Class of Practice of Medicine, University of Edinburgh. 
AN ETIOLOGICAL NOSOLOGY 
OF 
DISEASES OF THE SKIN. 
BY 
THOMAS LAYCOCK, M.D., F.E.S.E., &c„ &c 
PROFESSOR OF THE PRACTICE OF MEDICINE AND OF CLINICAL MEDICINE, 
AND LECTURER ON MEDICAL PSYCHOLOGY AND MENTAL DISEASES, 
IN THE UNIVERSITY. 
EDINBURGEI 
PRINTED BY NEILL & COMPANY. 
MDCCCLXII. INDEX. 
Physiological Proem, ...... 3 
Terminology, ....... 4 
Anatomy and Semeiology, ..... 5 
Classification of Cutaneous Inflammations, ... 5 
Etiology, ........ 9 
General Causes, . . . . • .10 
Local Causes, . . . • - .12 
Figurate Causes, ..... 13 
Etiological Nosology, . . . . . .14 
Hematic Diseases, . . . . . .14 
Specific Diseases, . . . . . .16 
Constitutional Diseases, . . . . .17 
Sordid Diseases, . . . . . .18 
Figurate Diseases, ...... 20 
Diseases of Special Cutaneous Tissues, . . .21 
PAGE AN ETIOLOGICAL NOSOLOGY OF DISEASES 
OF THE SKIN. 
Physiological Proem. — The skin is a complex structure, 
which may be likened to a composite secreting and excreting 
viscus spread out, so as to show the separateness and distinctness 
of its various elements. Or it may he considered as a musculo- 
mucous tube, with its subjacent tissues turned inside out over the 
surface of the body, so that the surface of the tube, with the 
outlets of the glandular ducts, is external, and the contractile and 
connective tissue subjacent or internal. 
Besides the structures and tissues proper of the skin, as a 
composite viscus or extended mucous membrane, with various 
gland-ducts opening upon it, there are the cutaneous appendages 
which belong to it as the structure of the body in immediate 
relation with external things. From this point of view the skin 
of man exhibits, either actually or potentially (i.e., is capable of 
exhibiting under given conditions), the appendages observed on 
the skin of lower unfeathered vertebrates. But even feathers and 
porcupine quills are analogous to hair, as well as horns and claws 
to nails, and hoofs and scales to the horny layer of epidermis. 
Parts of the human skin which are bare—i.e., have those tissues 
in an atrophied state which clothe homologous parts in other 
animals—may become clothed ; and portions which are devoid of 
colour in man or in white races may become coloured, or vice 
versa. In short, all these various appendages may undergo pro- 
gressive or retrogressive development, and also the glands in con- 
nection with them, as the sebaceous and sudoriparous glands. 
From these considerations arises a division of skin diseases, 
according as they are general and visceral; or according as they 
are local—the appendages, with their glands, being only involved. 
The general diseases of the skin, considered as visceral diseases, 
are to be grouped with those of the mucous membranes in general. 
Different tissues are affected in these general diseases, accord- 
ing as the mucous membranes or their glands are affected. In 
the majority of febrile cutaneous diseases, the rete mucosum and 4 
sweat-glands suffer in common with various mucous surfaces— 
buccal, pharyngeal, respiratory, gastro-intestinal, genito-urinary. 
In the Syphilitic group, the hair-follicles and sebaceous glands arc 
involved. There may be, however, strictly local diseases of the 
skin of this group, the mucous membranes remaining unaffected. 
Special tissues are involved in cutaneous inflammations. The 
skin is constituted of tissues having distinct functions, and sub- 
ject to the action of causes of disease peculiar to each. It is 
made up of three fundamental elements—the Epiderma, the Derma 
or Corium, and the Glandular System. The Epiderma, or cuticle, 
consists of (a) the horny layer or epithelium, which corresponds in 
composition with nails, hair, quills, hoofs, horns ; and (6) the rete 
mucosum, or layer of cells derived from the surface of the derma, 
and which produces the horny layer. The cutaneous pigment is 
contained in these cells in the coloured races, or becomes the seat 
of coloration in the white. It is continuous with the inner or 
secreting membrane of the cutaneous glands, and is essentially a 
mucous membrane. The Corium or Derma belongs to the system 
of fibrous and contractile tissues, as of the arterial tunic, bronchi, 
&c. It consists of connective and elastic tissue, with muscular 
fibres. It has two layers, viz., the inner or reticular layer, in 
which the hair-follicles and glands are imbedded, and the super- 
ficial or papillary layer*, containing the papillae, the ducts of the 
glands, and the vascular rete, which supplies the constituents of 
the cells of the rete mucosum. 
The Glands are involutions of the rete mucosum, or mucous 
membrane. Their cell-producing or lining membrane secretes 
albumen, pigments, oil, and sweat, and perhaps carbonic acid, 
with various odorous matters. The oil is poured out by the 
sebaceous glands—the sweat by the sudoriparous. The piliferous 
glands, or hair-follicles, and the sudoriparous glands, are deep in 
the connective tissue. The latter are convoluted tubes, consisting 
of a thick fibrous investment and an inner or cell-layer; between 
these are muscular fibres. They are also the scent-glands of the 
skin. The tissues of the skin, therefore, and its products, may 
be divided into three groups of fundamental tissues,—namely, 1. 
The mucous with its horny and other secretions ; 2. The vascular ; 
and, 3. The fibrous or connective, including muscular tissue. 
The causes of disease, and the anatomical and pathological changes, 
may be classed accordingly. 
Terminology,*—This is a chaos of names and synonyms, ex- 
tremely puzzling to the student, and obstructive to progress in 
cutaneous pathology. The time, however, has not yet come for 
a scientific nomenclature, so that it is only possible to simplify 
* The student is recommended to look out the origin of all the names of 
skin diseases in Dr Mayne’s “ Expository Lexicon,” as a useful exercise in the 
etymology of medical terras. the existing terms, by grouping those that are synonymous under 
one term selected from the rest as most descriptive either of the 
appearances, origin, progress, or termination of the disease. Hence 
terras indicating morbid variations in the colour, form, mode of 
spread on the surface, or extension of the disease, or clearly in- 
dicating the exciting or predisposing causes, are to be preferred. 
As to the general or universal diseases, the pathological results 
of morbid changes may also be named, because these are mainly 
the sequehe of inflammatory action of various kinds. Thus, in 
the variolas and varioloids we have circumscribed inflammation, 
either effusive or suppurative. This part of the terminology of 
skin diseases should also define, when possible, the particular 
tissue of the skin involved in the disease—as the papillae, the 
epithelium, vascular rete, derma, &c.; and must therefore, to 
this end, be based upon, and explain, the pathological anatomy of 
cutaneous diseases. 
Anatomy and Sem biology.—The results of cutaneous inflam- 
matory action may be classed according as they arc Primary or 
Secondary. To the Primary belong : 1. Redness, or pimply spots, 
Erythema—macula ; 2. Pimple—papula; 3. Lumps or tubercles— 
nodus, tuherculum; 4. Blains—including (a) tetter or vesicle, as 
in Herpes—vesicula; (6) Water blebs or blisters, large vesicles— 
bulla, phlyctcena, pomphus; 5. Pustules—(a) vesicular or jisy- 
dracious pustules ; (6) Purulent or phlyzadous pustules—Ex. 
Ecthyma; 6. Boil or carbuncle; 7. Haemorrhages. 
To the Secondary results of cutaneous inflammation belong, 
1. The production of epithelial scales—Dandriff, dry scale, or 
squamous inflammation ; 2. Crack or fissure of the derma ; 3. 
Excoriation of the epiderma; 4. Ulcer; 5. Slough; 6. Crusts or 
scabs; 7- Cicatrix; 8. Freckle, stain, or discoloration. 
These results of inflammatory action are often consecutive in 
the same case. Psoriasis, for example (a scaly disease) begins 
with a papula and sometimes ends with a discoloration; a 
rupious ulcer begins with a vesicle. Hence, in diagnosis from the 
pathological anatomy, the primary stages of the disease must be 
determined as well as the terminal. 
Classification of Cutaneous Inflammations.—I. Congestive 
Inflammations of the Skin. In these there is an increased number 
of red corpuscles circulating or heaped up within the capillaries of 
the vascular rete of the part affected. It is the first stage of in- 
flammation of any of the structures of the skin. The characteristic 
mark is increased redness. 
1. Erythema designates the congestive redness which occupies 
the derma, in homogeneous patches or otherwise, and not limited 
to or specially involving the papillary layer or the vascular rete 
of glands. 
2. Spotted, Maculated, or Pimply Inflammation, is (a) conges- 6 
tive inflammation of the vascular boundary surrounding the 
excretory or secretory ducts, as those of the sweat and oil glands 
and hair-follicles, or (6) of the tactile papillae. It is usually dis- 
tinct; hut when confluent, it passes into or is complicated with 
ei’ythema. Thus the congestive inflammation in scarlatina is first 
distinct and papular; then, as the inflammation advances, the red- 
ness becomes confluent. It is the first stage of all purely eruptive 
diseases of the skin, whether acute or chronic, commencing 
with a red spot. It is the most common form in typhus exan- 
thems. 
3. The redness of cutaneous inflammation varies in tint accord- 
ing to the condition of the blood or of the capillaries of the part, 
or of both. Inflammation of the surface (epiderma) is marked 
by a vivid rose red (burns or blisters); of the derma, by a dusky or 
deep red ; inflammation of the papillae is of a bright red. A\ hen 
the blood is morbid, the tint assumes a livid hue: Ex., Rubeola 
nigra. When morbid capillaries allow the morbid blood 
corpuscles to be effused, there are various tints of yellow, green, 
and purple, or lividity. Petechice are spots of papillary inflam- 
mation in which there is effusion of red corpuscles. If the effu- 
sion be in patches, the purple spots are vihices. The erythema 
in gouty inflammation is of a deep or mahogany red, changing 
into yellow; Ex., Erythema nodosum, E. arthriticum. This is 
probably due to diathetic causes influencing the blood corpuscles 
of the pai't (uric acid). Pigment deposits in the epiderma take 
place in chronic cachectic or diathetic states, and modify the in- 
flammatory tint; hence the “ coppery” hue in syphilitic inflam- 
mation, the liver colour in pityriasis versicolor, &c. 
4. (Edema is a frequent accompaniment of those acute con- 
gestive inflammations which depend upon the action of a fever- 
poison : Ex., Erysipelas—Variola. It indicates low capillary power, 
and is apt to precede effusive and destructive inflammations of a 
low type. 
5. Variations in Form of Congestive Inflammation.—Whether 
it be circumscribed or diffused, the redness may take a particular 
form or figure, or be figurate (figuratus). (a) It may advance 
by a margin (marginate): Ex., Erysipelas proserpens and Erythema 
marginatum. (6) The margin may assume a characteristic form, 
as—i. Crescentic: Ex., Rubeola, ii. Annulate or circinate: Ex., 
Erythema circinatum, E, annulatum, E. iris, iii. Gyrate: Ex., 
Roseola gyrata. (c) It may be symmetrical in its progress—that 
is, spread equally over the two halves of the body: Ex., Symme- 
trical erysipelas. These figurate forms of inflammation are equally 
manifested whether the inflammation be congestive, effusive, exuda- 
tive, suppurative, or ulcerative, and give rise to specific names; 
as Ex., Lichen Anmdatus; Herpes iris ; Psoriasis gyrata; Prurigo 
scutulata ; Herpes serpiginosus. &c. 7 
II. White Inflammation.—This occurs when empty capillaries 
take the place of the full or congested, or are intermingled with 
them. It may be diffuse, as inllrticaria; papillary, as in Strophulus 
albidus and S. candidus ; flgurate, as in Herpes iris or Variola 
vaccinia, in which red and white circles alternate. It may inter- 
mingle promiscuously with red papillary inflammation, as in the 
white pimples of Eczema rubrum. In a certain class of cases 
this white appearance is a circumscribed pallor, and due, probably, 
to a death-like condition of the capillaries. It is seen as a cen- 
tral point in anthrax; in certain forms of human glanders ; in 
the first stage of gangrene of the nose in the course of typhus, or 
from frost-bites, &c. It also occurs in cases of imperfect inner- 
vation of the cutaneous capillaries in which serum is poured from 
them, whether into the cellular tissue (anasarca) or from the 
surface (white effusive inflammation): Ex., Pemphigus. The 
emptying and filling of the capillaries may be intermittent or 
fleeting; Ex., Erythema evanidum, Urticaria evanida. 
III. Congestive Inflammation of the Skin, with Plastic Exuda- 
tion.—This is characterised by redness and swelling, which differ 
according to the portion of the skin affected, (a) Papillary exu- 
dation takes place when the papillary layer is the seat of inflam- 
mation ; the result is a small hard red elevation of the skin, termed 
a papula. 
These are seen in Strophulus, Lichen, and Prurigo, The 
papulae may be flat, pointed, or globular. In these forms the 
papillae are usually exclusively the seat of the exudation ; but it 
may take place also into the connective tissue or sheath of the 
sebaceous glands (Acne rosacea, A. indurata). The congestion 
usually extends to the interspaces, and erythema is conjoined with 
the papulaa, (6) Tubercular inflammation of the derma occurs 
when there is exudation into the deeper connective tissue of the 
derma, or of that constituting the fibrous investment of the 
sudoriparous or piliferous glands : Ex., Tubercular syphilis, 
Erythema nodosum, E. tuberculatum, (c) The exudation may 
be diffusely circumscribed, and occupy the connective tissue gene- 
rally, as in Urticaria, Condyloma; or (c?) may extend to the subcu- 
taneous cellular tissue, ending in anasarca and suppuration, as in 
Erysipelas phlegmonoides; or in induration, as in True Leprosy 
and Barbadoes Leg. 
IY. Effusive Inflammation of the Skin. — When, after con- 
gestion or irritation of a portion of the vascular rete of the 
epiderma, or of the papillar or excretory ducts, effusion of serum 
takes place, and it is retained beneath the epithelium or horny 
layer, a bleb, blister, or vesicle is formed. The extent, colour, 
form, and other characteristics of this effusive inflammation, 8 
coincide, mutatis mutandis, with those of congestive inflammation. 
When the papillae are specially involved, and the vesicles burst, 
leaving a bare exuding surface, the disease is Eczema; when the 
vesicles form in clusters, and are confluent, it is Herpes. If they 
be large and solitary, it is Pemphigus or Pompholix. 
Effusive inflammation will pass into the suppurative; or, in 
other wmrds, pus is formed on the inflamed surface. Hence cer- 
tain diseases, as the Variolas, are vesicular in the earlier stages, 
and suppurative in the later, ending in sloughing, excoriation, or 
ulceration. 
Effusive inflammation will be figurate, following in this respect 
the law of form of the congestive inflammations. The vesicles 
will multiply by a margin from a centre, as in Herpes circinatus, 
or one vesicle will be the centre for an ulcerative inflammation 
spreading by a margin, as in Pemphigus or Rupia. The vesicles 
will also be developed symmetrically, as in Herpes zoster, or be 
intermingled with purple petechias, as in Variola cum petechiis. 
V. Suppurative Inflammation of the Skin.—The term is limited 
to abscess of the derma; of which there are two forms,—namely, 
pustules, and abscesses proper, in which the subcutaneous tissue 
and lymphatic glands are involved. 
Pustular suppurative inflammation is always circumscribed. 
(a) It may be acute as to each pustule, and as to all; Ex., Vario- 
lous pustules. (6) It may be acute as to each pustule, but 
chronic as to all, when pustules follow each other in succession : 
Ex., Parasitic pustular inflammations—Sycosis, Scabies, Acne, 
(c) The suppuration may be superficial, and restricted to the papil- 
lary layer, when the pustule is usually sero-purulent or psydra- 
cious : Ex., Impetigo. (d) Or it may be deeper-seated in the 
reticular layer, causing the phlyzacious pustule: Ex., Ecthyma, 
(e) It may be complicated with other forms of inflammation— 
i. Exudation into the connective tissue: Ex., Acne indurata, 
Boil, Ecthyma chronicurn. ii. Effusive papillary inflammation : 
Ex., Scabies pustulosa, Eczema impetiginoides, Impetigo erysipe- 
latodes. (/) It may differ according as it terminates—i. In cica- 
trization : Ex., Variola, Ecthyma, ii. In ulceration and crusts : 
Ex., Crusta lactea, and other forms of Impetigo, iii. Gangrene 
or sloughing ; Ex., Ecthyma luridum, Carbuncle, or Anthrax, 
(p) It may be figurate : Ex., Impetigo figurata. 
Abscesses of the derma are (a) circumscribed—Ex., Glanders ; 
or (6) diffused—Ex., Erysipelas phlegmonoides ; or (c) limited, as 
when caused by Ectozoa, the Guinea worm, ova of chiggre, &c. 
VI. Ulceration of the Derma.—The term is limited to chronic 
ulcerations. («) May he circumscribed and superficial, as in 
chronic Impetigo, rodent nicer; or (h) circumscribed and deep- 9 
seated, with exudation into the reticular tissue, when it is ulcer- 
ative tubercular inflammation: Ex., Lupus exedens, Leprous ulcers, 
Gouty ulcers, (c) May be uncircumscribed—Strumous ulcers. 
Ulceration may spread by a margin, either superficially, as in 
Herpes serpiginosus, Lupus serpiginosus, rodent ulcers, syphilitic 
ulcers. In this and other respects, spreading ulceration follows 
the laws of spreading inflammations, and may be figurate. 
VII. Destructive Inflammation of the Derma.—(a) The in- 
flammation terminates in death of the tissues. May be circum- 
scribed, as in furuncle; or spread by a margin, as phagsedenic ulcer 
of skin, (6) The inflammation terminates in atrophy of the 
derma: Ex., Lupus non exedens, Keloid. 
VIII. Cutaneous Haemorrhages.—The capillaries of the vas- 
cular rete give way under certain morbid states, and haemorrhages 
take place. When the connective tissue or surface of the papillary 
vascular rete is the seat, the haemorrhage is punctiform: Ex., 
Purpura in P. haemorrhagica. When it is situate in the vascular 
rete of the sudoriparous glands, it is nodose; when diffused over 
the surface, as in advanced scorbutus, the patches are vibices. 
Cutaneous haemorrhages may be symmetrical, and due to changes 
in the action of the nervous system; in this and other re- 
spects they follow the order of congestive and effusive inflam- 
mations. 
IX. Discolorations of the Skin.—These may depend either 
upon the absence of pigment in the epiderma where it ordinarily 
occurs (Leucopathia), or the presence of pigment where it ordi- 
narily is not (Yellow bronzing; Melasma), When the change is 
in the colour of the hair, it is generally to whiteness (canities). Pig- 
ment may be poured out by the sebaceous and sudoriparous glands; 
in the former case (Stearrhoea nigricans, &c.) it is like the epithe- 
lial or hair pigment, in the latter (chromidrosis) it belongs to 
the urinary pigments. 
Epidermal pigment deposit results from congestive and effusive 
inflammations of the epiderma; as in solar erythema and lichen, 
herpes, blisters. Ordinary pigmentation is prevented by ulcera- 
tive inflammation of the epiderma, the pigment layer of cells (rete 
mucosum) being destroyed, when leucopathia results. These 
colour changes may be figurate, in accordance with the general 
laws of figurate cutaneous inflammations. They are symmetrical 
when the discoloration is due to changes in the innervation of 
the vascular rete of the epiderma or the glands. 
Etiology of Skin Diseases.—The causes of skin diseases ma 
be classed under the three heads of General, Local, and Figurate. 10 
I. General Causes.—These may be either Haematic, Toxic, or 
Constitutional (diathetic). 
1. Hcematic Causes are those agents which act upon the cuta- 
neous tissues through the circulation, being either present or 
multiplying in the blood, and which induce haematic cutaneous 
diseases. These include the entire group of febrile cutaneous 
diseases, as the Exanthemata, and all acute or chronic cutaneous 
diseases dependent upon blood-poisons. When the poison in- 
creases or multiplies, and is communicable from one person to 
another, the disease is infectious or contagious; Ex., Variola, 
Syphilis. When after one attack (variola), or several attacks 
(syphilis) of the cutaneous inflammation, the patient is no longer 
morbidly susceptible of the action of the poison, it is non- 
recurrent. 
2. Toxic Causes.—When certain mineral and vegetable poisons 
are received into the blood, and circulate with it through the 
capillaries of the vascular rete of the skin, they excite, under given 
conditions, various forms of inflammation, which may be termed 
Toxic cutaneous inflammation. Of this class of causes there is a 
great variety ; amongst these, (a) Mineral Poisons, as mercury, ar- 
senic, iodine, sulphur’, and their salts ; (6) Narcotics—Belladonna, 
opium, hydrocyanic acid; (c) Terebinthinates, tar, copaiba; (d) 
Dietetic Poisons—Poisonous fish, fruit, fungi, &c. In addition to 
erythematous, papular, or effusive inflammations (erythema, lichen, 
Herpes eczema, pemphigus), these toxic agents for the most part 
excite also pruritus, formicatio, or stinging. 
3. Constitutional or Diathetic Causes.—It not unfrequently 
happens that the predisposing and exciting causes of skin-diseases 
arise or take effect only in persons of certain habits, or of a parti- 
cular diathesis, or having special cachetic conditions of the blood 
or tissues, or hereditarily, or at a certain age, or in one or other 
of the sexes. These constitutional conditions may be classed as 
follows:— 
(a.) Nervous Diathesis.—Predisposes to—i. Excessive activity 
of the vascular rete on the application of causes ; ii., Excessive re- 
ceptivity of the nerve-centres, and therewith susceptibility to 
action of causes, otherwise harmless, of cutaneous inflammations 
and neuroses. Hence idosyncrasies as to articles of food, drugs, 
and various local irritants of the skin; tendencies to prurigo and 
pruriginous affections—as Urticaria, Erythema evanida. The 
cutaneous diseases proper of this diathesis are included under the 
Neuroses. 
(h.) Arthritic or Gouty Predispositions.—The determination 
of urates to the skin, as a causa morbi: is amongst the best estab- 
lished facts of pathology; uric acid has been found in the blebs 
of pemphigus. The gouty skin-diseases are a distinct group, 
and may be classed according to the tissue affected—namely, the 11 
epiderma, or the connective tissue of the derma; and according 
as the inflammation is congestive, effusive, or desquamative ; or 
acute or chronic: middle life and old age are most predisposed. 
The ulcers on the legs of old persons, with hardened edges and 
condensed connective tissue below, are often arthritic; so also the 
fetid perspirations of the feet. The arthritic diathesis predisposes 
more especially to all those febile cutaneous inflammations in which 
the connective tissue of the derma, or of the sudoriparous glands 
are involved : Ex., Syphilis. It also predisposes to diathetic pur- 
pura, to pigmentary changes of a diathetic character in the hair 
and epithelium; andTn women to nervous hamorrhages from the 
skin. Children of gouty parents are apt to have depositive inflam- 
mations, as Strophulus and Lichen, and severe attacks of scarlatina 
and rubeola. 
(c.) Strumous Diathesis and Cachexia.—Infancy and childhood 
manifest this class of diathetic predispositions most strongly. 
Under certain conditions (as dentition), it predisposes to rapid 
development of the epithelium (dandriff), to active inflammation 
when haematic or local causes are applied, and to a rapid evolution 
of its successive stages—viz., effusion, suppuration, and idceration. 
Hence, strumous children are particularly liable to severe attacks 
of the effusive and suppurative Exanthemata. They are, for the 
same reasons, predisposed to cachectic diseases of the skin, as 
chronic pemphigus and ecthyma ; to parasitic diseases of all kinds, 
as pediculi of the scalp, scabies, favus, impetigo, together with 
enlargement and ulceration of the cutaneous lymphatic glands. 
In strumous adults, low forms of diseases are manifested, as lupus, 
cutaneous cancer, zeroderma, inveterate squamous diseases, atro- 
phic diseases of the hair, parasitic diseases, as prurigo, morbus 
pediculosus, &c. The group includes all cachectic diseases. 
(d.) Syphili-strumous Diathesis.—It is necessary to distinguish 
between cutaneous diseases due to the action of the syphilitic 
poison, which are specific and communicable, and those that are 
ordinary diseases of the skin occurring in persons of a syphilitic 
habit or diathesis, and which are modified thereby as to their 
symptoms and course. In the syphili-strumous diathesis there is 
a tendency to defective nutrition of the connective tissue, both of 
the derma proper and of the glands therein. Hence a dingy 
pallor of the surface, imperfections in the horny layer, defective 
nutrition of nails and hair, defective transpiration'and sebaceous 
secretion. Inflammation and its sequelae—exudation and ulceration, 
occupy for the most part the connective tissue, and are of a low 
type. These constitute a group of cutaneous diseases to which a 
peculiar or special cachectic character is given by the diathesis. 
(e.) Age and Sex.—Certain groups of glands and hair-follicles 
are under the direct influence of the generative glands, being de- 
pendent upon them for development, or activity, or influenced by 12 
physiological states of the generative organs. In this way certain 
ages, as well as the sexes, manifest particular forms of cutaneous 
disease. The sebaceous and scent-giving sudoriparous glands 
situate in the region of the sexual hair, are most commonly 
thus influenced. Hence various forms of acne, stearrhsea, bald- 
ness or atrophy of the hair, and discolorations (nigrities). The 
mammae are highly developed sebaceous glands, and are some- 
times multiple in women, being developed abnormally in the 
axillary regions and groins. The sudoriparous glands also pour 
out pigments and scents under the like influences, and fat, in 
women, is deposited in the subcutaneous cellular tissue. 
(/.) Hereditary Tendencies.—These are to be distinguished 
into (a) the Diathetic, when there is a tendency to certain classes 
of diseases; and (6) the Special, when there is a tendency to par- 
ticular forms of disease, as ichthyosis, lepra, psoriasis, erythema 
of the nose and face, &c. 
II. Local Causes of Cutaneous Diseases.—These may act either 
generally, or upon special glands or tissues, developing special 
forms of disease. 1. All haematic poisons may act locally, and 
excite local symptoms only: Ex., the plague bubo, erysipelatous, 
scarlatinal, and diphtherial inflammation. 2. Dynamic causes 
may act either locally only, or, by their local action, intensify the 
operation of general or haematic causes. Hence the origin of local 
eruptions on the face, and the aggravation of these in variola, 
rubeola, &c. Heat, light, abstraction of heat, or cold, friction, 
and the atmosphere, are of this class. 3. Accumulated animal 
matters on the skin; as sordes, excreta, crusts, oil, scales. These 
act either as irritants, or predispose to the production of parasitic 
organisms. 4. Parasitic organisms. These are of two kinds, 
the animal, or ectozoa, and the vegetable, or epiphytes. They 
differ as they are indigenous and have their habitat on the human 
skin, in which case they multiply thereon ; or as their habitat is 
on other animals, as the horse or sheep, or elsewhere, as in sugar, 
flour, when they do not necessarily multiply in or on the skin. 
This difference determines whether the disease terminates spon- 
taneously, or requires to be cured by preventing the multiplica- 
tion or reproduction of the parasite. The inflammations and 
other changes induced by parasites may be figurate or not. If 
ectozoa be the cause, papular, effusive, and suppurative inflam- 
mations result (scabies), or abscess (ova of the Pulex penetrans 
or chiggre, and Filaria medinensis or Guinea worm) of no deter- 
minate form. If the epiphytes, these morbid appearances are 
often figurate in various ways. This is due to the conditions of 
life and multiplication of the parasitic organisms. 5. Mechanical 
and chemical irritants. These are of various kinds, as powders, 
dyes of clothing, detergent soaps, needle-like products of animals 13 
and vegetables, poisons inserted locally, as of the stinging 
nettle, &c. 
III. Causes of FigurateDiseases oftheSkin.—This is a proposed 
new group of cutaneous diseases, to include those in which the 
cause of disease multiplies locally in the cutaneous tissues, and 
spreads symmetrically, so as to assume a determinate outline or 
figure. This may be—i. Symmetrical, as to the body or limbs ; 
when the state of the sympathetic nerves of the skin may be con- 
sidered the determining cause of the form assumed ; Ex., Herpes 
zoster, or zona. ii. Marginate. In these there is probably a 
multiplication of the materies morbi in the skin itself, as part of 
the morbid process, in which case the disease is locally con- 
tagious ; or, in other words, the diseased condition extends along 
the skin by a margin, in consequence of progressively direct 
inoculation of the healthy tissue by a materies morbi generated 
in the tissues successively affected—as in Erysipelas proserpens, 
Lupus serpiginosus. iii. Circumscribed or circidar. (a) The 
crescentic form, as in rubeola, seems due to the anatomical dis- 
tribution of the capillaries or of their nerves, and belongs, there- 
fore, to the symmetrical class. (b) The circinate is due to the 
spread of the materies morbi from a centre by a circumference, as 
in Psoriasis circumscripta, Herpes circinatus, H. Iris, (c) 
This will be annular or ring-like when that portion of the skin 
which has been first affected (the central) is restored to health, 
while the morbid action extends at the periphery, as in Lepra 
vulgaris, ((i) When the spread in the annular form is inter- 
rupted at a segment of the circle, and two or three of these coalesce, 
the form assumed is the gyrate. (e) When a number of centimes 
and circumferences of spread have become confluent, so as to 
occupy a considerable surface, the general is serpiginous, as in 
Lupus serpiginosus. 
The materies morbi which thus multiply in or on the skin or 
its tissues, may also be classed—i. The Hoematic, in which a 
local inoculation having occurred, the materies multiplies locally, 
and the disease spreads symmetrically; but at the same time the 
blood is affected, and the materies, multiplying therein, is 
deposited from the blood on other portions of the surface. There 
are two forms of these haematic figurate inflammations,—namely, 
the acute and the specific. Under the acute are to be classed 
the figurate exanthems resulting from the virus generated in 
the exanthematic fevers. The specific are illustrated by true 
syphilis, in which the primary or local sore (chancre) is cir- 
cular or circinate, and the exanthems of the secondary or consti- 
tutional stage are also circinate. These are probably modified by 
diathetic states.—ii. The Diathetic. In this class there is a mode 
of morbid nutrition developed in the cutaneous tissues, which 
is manifested as a special form of inflammation. And it seems 14 
probable that when diathetic inflammation is developed locally by 
local causes, the adjoining tissues take on morbid action, in con- 
sequence—not of the action of the local cause—but of the inflam- 
mation it has induced extending by contiguity. This seems to 
be the mode of spread in certain forms of diathetic erysipelas or 
erythema, usually termed gouty, and in herpes and pemphigus.— 
iii. The Epiphytic. In this class the materies morhi is a 
fungus, lichen, or mould, and follows the laws of multiplication 
of the Cryptogamia. In epiphytic figurate diseases, the circular 
form (it has been suggested) is probably due to the same cause as 
the circular form of lichens on rocks and stones, of “fairy rings” 
in meadows, and the like. The extension or cessation of the dis- 
ease will depend upon the multiplication and dying out of the 
cryptogamous plants ; and these will depend upon whether the skin 
offers conditions favourable or unfavourable to their continued 
existence and reproduction. Hence it is only under certain con- 
ditions of patients that these epiphytic diseases can occur at all, 
or, in other words, be induced or communicated. A general law 
seems to be common to the entire class,—namely, that they mul- 
tiply most rapidly on diseased organisms, whether they be animal 
or vegetable. Hence cachectic or diathetic states highly pi'edispose 
to epiphytic diseases. These states also seem not only to deter- 
mine the kind of inflammation which results from the action of 
the parasites, but also the form which they or their reproductive 
organs assume. Or in other words, there is great variety as to 
the form and modus operandi of epiphytic organisms of the same 
species, so that it has been stated that the Achorion of Favus can 
be developed into the Torula cerevisise, or into the microsporons. 
ETIOLOGICAL NOSOLOGY. 
I. Haematic or Febrile Diseases of the Skin.—A virus multi- 
plying in the blood and the cutaneous tissues excites fever and 
inflammation of the skin (an exanthem). 
1. Herpetic Fevers.—Exanthem—Herpes, clustered vesicles, 
usually about the lips—Herpes labialis. Occurs in both 
endemic and epidemic fevers. 
2. The Exanthemata.—Exanthem very constant, but not 
essential; one attack prophylactic against a second. 15 
i. Variola and the Varioloids.—Exanthem at first 
papular, then vesicular, pustular, and ulcerative. 
In irregular forms, effusive, papular, or petechial, ery- 
sipelatous. 
ii. Rubeolar Fevers.—Morbilli; Rubeola ; Inflammation 
congestive, at first roughly papular or pulicular, then 
confluent, crescentic. In irregular cases, erythemat- 
ous or scarlatinal, vesicular, miliary, petechial. 
iii. Scarlatinal Fevei’s.—Congestive inflammation of the 
epiderma—at first papular, then confluent, sometimes 
interminged with vesicles, with inflammation of the 
throat-glands, external or internal, or both. 
iv. Diphtheria cutanea.—Exanthem, a pellicular inflam- 
mation of portions of the skin, conjunctiva, &c. May 
be wholly local, but usually accompanies the buccal, 
pharyngeal, and tracheal forms of diphtheria. 
3. Exanthematous Typhus Fevers.—Epidemical fevers, one 
attack prophylactic of a second. Cutaneous inflammation, 
congestive, macular, papular, or carbuncular. 
i. Exanthematous Typhus—Spotted Typhus. Exanthem 
congestive, macular, or papidar,of a deep or mulberry- 
red, appearing about the fifth day. May be petechial 
or vesicular (Petechial Typhus; Miliary Fever), 
ii. Glandular Typhus—Levant Plague. Exanthem con- 
gestive and rubeoloid ; cutaneous glands and lym- 
phatics inflamed (Buboes and Carbuncles). 
iii. Bilious Typhus—Relapsing Fever, European Yel- 
low Fever 1 Exanthem, when present, papular, 
rubeoloid. 
iv. European Gastro enteric Typhus—Typhoid Fever. 
Exanthem papular, of a rose-colour, appearing first 
about the seventh day. 
v. Occidental Gastric Typhus—Yellow Fever.—Exan- 
them, when present, rubeoloid or papular. Super- 
ficial and diffused cutaneous haemorrhage ? 
vi. Asiatic Gastro-enteric Typhus—Asiatic Cholera— 
Epidemic Cholera. — Exanthem occurs in typhus 
stage; macular, papular, diffused, and desquamative. 
4. Septic Cutaneous Fevers.—Due to a sepsis or putrescent 
ferment received into the blood. 
i. Erysipelas proserpens.—Exanthem an erythema, with 
oedema or effusive inflammation; serpiginous, mar- 
ginate. ii. Erysipelas phlegmonoides.—Exanthem 
red or white; subcutaneous cellular tissue involved, 
iii. Erysipelas Glandularis—Inflammation phlegmo- 
noid, erythematous, effusive; cutaneous lymphatic 
glands enlai’ged and suppurating. 16 
5. Epizootic Cutaneous Fevers.—Virus derived from cattle 
and horses. 
i. Equinia or Maliasmus—Human Glanders.—Inflam- 
mation oedematous and erysipelatous, with bullae; sup- 
purative and destructive as to termination, ii Car- 
buncular Fever.-—Inflammation erysipelatous, car- 
buncular, gangrenous ; Anthrax; Phlegmonous ery- 
sipelas. 
II. Specific Diseases of the Skin.—Impure Fevers, A virus 
multiplying in the blood, and exciting recurrent attacks of 
fever and inflammation ; insusceptibility to the action of the 
virus finally established. 
1. True Leprosy.—Inflammations usually recur during the 
lifetime in various forms : (a) Erythematous ; (6) Des- 
quamative; (c) Pigmented (black leprosy); (d) Tuber- 
cular or plastic, with or without ulceration; (e) Effusive 
(in blebs), with anajsthesia of the skin and gangrene of the 
extremities ; (/) Parasitic (Acari and pediculi). 
2, The Syphilids.—Inflammation recurrent in acute febrile 
paroxysms; various as to race, climate, and constitution. 
i. Benign Syphilis. Inflammation for the most part 
limited to the epiderma and papillae; connective tissue, 
and fibrous or sero-fibrous membranes generally, not 
commonly involved, (a) Virulent Gonorrhoea. Prim- 
ary ulcer, a patchy excoriation ; exanthem rubeolar 
or macular. (6) Papular Syphilis. Primary ulcer 
simple, exanthem papular, (c) Pustular Syphilis. 
Primary ulcer with raised but not indurated edges; 
exanthem effusive and suppurative, ending in crusts 
and superficial ulcerations, (d) Phagsedenic Syphilis. 
Primary ulcer either corroding or gangrenous, exan- 
them pustular or tubercular, ending in crusted mar- 
ginate ulcers (Rupia) ; not always benign. 
ii. True, or Scaly Syphilis. Inflammation occupies con- 
nective tissue of the derma. Primary ulcer excavated, 
with thickened edges and base (specific plastic exuda- 
tion). Exanthem at first congestive, ending in (a) 
desquamation; (6) tubercles and ulceration; (c) con- 
dylomata; (d) fungoid growths; (e) periosteal in- 
flammation, and deposits in connective and fibrous 
tissues generally. 
iii. Ethnic and Climatic Syphilis, (a) African Syphilis. 
Yaws, or Pian ; Framboosia. Inflammation at first 
congestive and superficial; then deeper seated, with 
rupia like ulcerations and yaws or fungoid figurate 
growths (mulberry-like). (6) Norwegian Syphilis. 17 
Radesyge or wheel-like cachexia. Exanthem figurate, 
papular, pustular, tubercular; ulcerations rupious, 
marginate, serpiginous, (c) Levant Syphilis—Scher- 
lievo. Framboesia of Eastern Europe. Exanthem 
pustular, tubercular ; ulcers figurate, rupious ; con- 
dylomata and yaw-like fungoid growths, (d) Scot- 
tish Framboesia—Sibbens. Exanthematous inflam- 
mation both deep-seated and superficial ; roseola, 
followed by condylomata and fungoid figurate growths 
(like raspberries). (e) Button Scurvy, Irish Fram- 
bcesia or Sibbens. 
3. Contagious (?) Furunculoid.—Inflammations of the skin 
occurring epidemically. Exanthem in successive crops, and 
various; impetiginous, ecthymatous, furuncular, carhuncu- 
lar, gangrenous. Cause unknown; probably communicable. 
III. Constitutional Diseases of the Skin.—Diseases dependent 
on constitutional conditions, either predisposing or exciting, and 
due to (a) a rnateries morbi produced in the blood or tissues ; 
or (6) to special modes of nutrition of the skin and its struc- 
tures, occurring with or without fever. 
1. Rheumatic and Gouty Diseases of the Skin are acute and 
chronic, and congestive, effusive, and capillary. 
i. Congestive Gouty and Rheumatic Diseases, (a) Ery- 
sipelas; (b) Roseola; (c) Urticaria—U. evanida, U. 
perstans, U. tuberosa (cachectic) ; (d) Erythema—E. 
fugax, E. la?ve (cachectic), E. nodosum, E. tubero- 
sum, E. papulatum, E. podagricum, E. chronicum. 
ii. Papular Rheumatic or Gouty Diseases, (a) Lichen— 
L. urticatus, L. pruriginosus, L. agrius or eczema- 
toides, L. evanidus, L. tropicus, L. infantilis or 
Strophilus; (6) Prurigo. (These two groups of 
congestive and papular diseases are apt to occur in 
persons who have an idiosyncrasy for special articles 
of diet or for drugs, and to he associated with cuta- 
neous and other neuroses.) 
iii. Effusive Gouty and Rheumatic Diseases. (a) 
Herpes—H. zoster, H. phlyctenoides. (h) Eczema 
—E. ruhrum, E. senilis, E. infantilis, E. serpi- 
ginosura. (c) Pemphigus—P. acuta, P. chronica. 
iv. Desquamative Gouty and Rheumatic Diseases. 
These are consecutive to the congestive, papular, and 
effusive forms, (a) Pachulosis (inveterate eczema) ; 
(6) Psoriasis diffusa ; (c) Pityriasis versicolor 
(cachectic). 
v. Capillary Gouty and Rheumatic Diseases, (a) Acute 
Purpura haemorrhagica ; (6) Purpura urticans; (c) 18 
Diathetic haemorrhages (haemorrhagic diathesis); 
Hysteric haemorrhages (neuro-arthritic diathesis). 
2, Cachectic Diseases of the Skin—are diseases in which the 
cutaneous inflammations or structural changes are modi- 
fied by cachectic states of the blood and tissues. They are 
infantile, senile, strumous, syphili-strumous, cancerous, 
visceral; and, for the most part, effusive, squamous, sup- 
purative, ulcerative, or dystrophic. 
i. Cachectic, Effusive, and Suppurative Diseases, (a) 
Crnsta lactea (infantile). (b) Impetigo—I. sparsa, 
I. figurata. (c) Ecthyma—E. chronicnm, E. ca- 
checticum, E. lividum, E. furunculoides. (d) 
Rnpia—B. syphilitica, R. escharotica, R. promi- 
ncns. (e) Carbuncle. 
ii. Cachectic Squamous Diseases. (a) Favus ? (6) 
Psoriasis inveterata ; (c) Pellagra. 
iii. Cachectic Diseases of the Capillaries and Blood. 
Purpura—P. senilis, P. scorbutica, P. splenica. 
iv. Cachectic Ulcers, (a) Strumous. (6) Gouty, (c) 
Chlorotic (on legs). (d) Splenic (on legs), (e) 
Syphilitic. (/) Leprous, cancerous. 
v. Dystrophic Diseases, (a) Zeroderma (wrinkled skin). 
(6) Alopaecia—A. senilis, A. syphilitica, (c) Epi- 
thelioma ; (d) Keloid ; (e) Vitiligo, or Leuce. 
IV, Sordid Diseases of the Skin—are diseases primarily de- 
pendent upon an unclean condition of the skin, either as to 
excreta, products of inflammation, parasitic organisms, or inor- 
ganic matter, or as to all these ; often associated with cachectic 
states of the general health or of the skin, and appear more 
particularly in children and the aged of cachectic habits. 
1. Parasitic Diseases of the Skin.—Parasitic organisms mul- 
tiplying and exciting morbid changes in the skin. 
i. Ectozoic Diseases.—Inflammations dependent upon 
the presence of an animal parasite or ectozoon. 
(а) Scabies group. Varieties of itch, caused by a 
Sarcoptes or Acarus. a. Scabies vulgaris, 
caused by human Arams. Varieties—S. papu- 
laris (rank itch), S. vesiculosa, S. pustulata. 
b. Epizootic Scabies, caused by Sarcoptes from 
animals ; viz., Acarus setosus, or bovis (cow) ; 
A. cynotis (dog’s ear canker) ; A. bippopodis 
(horse’s foot canker) ; A. fclis, mange, c. Arti- 
san’s Scabies, caused by Acari (?) from sugar, 
flower, silk cocoons, &c.; Grocer’s itch ; Baker’s 
itch ; Silk cocoon winder’s itch. 
(б) Acari or epiphytes in sebaceous follicles. 19 
Doubtful group. a. Acne—A. vulgaris, A. 
rosacea, from Acarus folliculorum ? Sycosis 
faciei ? Impetigo faciei \ b. Lupus—L, serpi- 
ginosusl L.exedensl Molluscum contagiosum? 
(c) Phtheiriasis—a. Morbus pediculosus. From 
pediculi; P. capitis, P. pubis, P. corporis, b. 
Prurigo—P. vulvse 1 P. podicis ? 
(c?) Pulicular Diseases. From the pul ex—a. Ma- 
culae puliculares (flea-bites), b. Abscessus pedis 
(ova of Pulex penetrans). 
ii. Epiphytic Diseases—Diseases of the skin, caused by 
the multiplication of microscopic fungi and algae on 
the epiderma, in the sebaceous ducts and hair-follicles, 
and on the hairs. They are congestive, effusive, and 
ulcerative, and lead to desquamation, and to atrophy 
of the hair. 
(a). Ringworms.—Circular inflammations of the epi- 
derma, usually desquamative, but sometimes con- 
gestive only, or ending in effusion, suppuration, or 
ulceration, with impaired nutrition of the hair. 
Seat the epiderma and hairs or hair-papillse; 
cause a microscopic fungus—the Tricophyton 
tonsurans (Gruby) or Tricophyton decalvans 
(Malmsten) or Microsporon Andouini. 
a. Ringworms of the scalp, characterised by 
desquamation and baldness. Trichosis (Mason 
Good). Trichosis furfuracea; Trichonosis 
furfur; Tinea tonsurans; Porrigo furfurans, 
P. scutulata, P. circinata, P. tonsorea, P. 
decalvans; Alopsecia circumscripta, A. areata, 
A. gyrata; ophiasis, b. Ringworms of the 
face, limbs, and trunk. Inflammation 
papular, ending in scales or vesicles. Varie- 
ties, Lichen and Herpes—L. circumscriptus, 
L, annulatus, L. gyratus, L. marginatus, 
L. figuratus, L. serpiginosus; Herpes circin- 
atus, H. circinatus phlyctenoides, Pemphigus 
circumscriptus. c. Squamous ringworms. 
Doubtful as to epiphytic causes. Varieties: 
Lepra vulgaris ; Psoriasis gyrata, P. circum- 
scripta, P. centrifuga, P. palmaris. 
(6.) Tinea or Favus. — Figurate or uncircurascribed 
diseases of the sebaceous glands and hair-follicles 
of the scalp, face, and trunk, extending to the 
epiderma, and ending in scales, crusts, excoriations, 
pustules, or ulcers. Causes : the Achoi'ion Schon- 
leinii (Remak). 20 
a. Tinea or Favus of the Scalp. Yellow circular 
crusts, the centre at the orifices of the hair- 
follicles, coalescing or figurate. Erythema, 
Excoriation, or Ulcer of the Epiderma. Va- 
rieties—i. Distinct Favus—F. urceolatus, F. 
disseminatus, F. furfuracea, F. dispersus, F. 
isolatus; Porrigo favosa—P. lupinosa. ii. 
Patchy or figurate Favus. Favus confertus— 
Porrigo scutulata, P. scutiformis, P. scutu- 
lata conferta. iii. Confluent Favus—Porrigo 
squamosa, P. larvalis; Eczema chronicum. (?) 
(b.) Tinea or Favus of the Face, Body, and Limbs. 
Favus urceolatus, raentagra, Sycosis menti, S. 
furfur, S. pustulosa. 
(c.) Diffused Epiphytic Squamous Diseases.—Cause 
the Microsporon furfur (Eichsted) or Achorion 
Schonleinii. Pityriasis—P. rubra capitis, P. pal- 
pebrarum, P. versicolor ; Onyxis ; Alopsecia ? 
Y. Figurate Diseases or the Skin.—Are Hsematic, Diathetic 
and Parasitic, and, in being developed, spread by a margin or 
assume the form of a circle, or of a segment thereof. 
1. Figurate Congestive Inflammations, (a) Rubeola; Rose- 
ola—R. vaccinia, R. annulata. (6) Erythema—E. iris, E. 
circinatum, E. annulatum (Palmare), E. marginatum, (c) 
Erysipelas—E. marginatum, E. proserpens, (d) Urticaria 
gyrata. 
2. Figurate Depositive Inflammations.—(a) Papillary, i. 
Lichen—L. annulatus, L. circumscriptus, L. figuratus, L. 
gyratus, L, serpiginosus, L. marginatus, L. tuberculatus 
annulatus, ii. Strophulus volaticus (circinatus). (6) 
Dermic, i. Condyloma, ii. Tubercle. 
3. Figurate Effusive Inflammations, (a) Herpes—II. iris ; 
H. circinatus; II. proserpens ; H. serpiginosus; H. 
tonsurans. (6) Pemphigus—P. circumscriptus. (c) 
Eczema—E. serpiginosus. 
4. Figurate Squamous Inflammations, (a) Lepra vulgaris. 
(b) Psoriasis—P. gyrata, P. circumscripta, P. centrifuga, 
P. annularis. 
5. Figurate Suppurative Inflammations.—(a) Porrigo: P. 
Favosa? (Favus), P. scutulata, P. circinata. (b) Impe- 
tigo figurata. 
6. Figurate Ulcerative Inflammations.—(a) Rupia; (6) 
Lupus—L. exedens, L. exedens serpiginosus; (c) Ulcus 
rodens; (a?) Framboesia (fungoid); (e) Hunterian chancres. 
7. Figurate Dystrophic Diseases.—(a) Porrigo decalvans ; 
(6) Alopcecia ; A, circumscripta ; A. areata; A. gyrata; 21 
(c) Ophiasis; (d) Lupus non exedens; (e) Kelis ovalis; 
(/) Melanosis circumscripta. 
VI. Diseases of Special Cutaneous Tissues. 
1. Horny and Papillary Layer.—(a) Papillary nsevus; (b) 
Pachulosis; (c) Verruca (Warts); (d) Tylosis (Laminated 
Corns) ; (e) Clavus (Fibrous Corns); (/) Onyxis. 
2. Vascular Mete.—Vascular nsevus. 
3. Colour Rete.—(a) Pigmentary naevus; (6) Epbelis (Sun- 
burn) ; (c) Lentigo (Freckle); (d) Chloasma (Pityriasis 
versicolor); (e) Melasma (yellow and swarthy) ; (/) Me- 
lanosis ; (y) Leucopathia. 
4. Diseases of Cutaneous Glands.—(a) Sudoriparous Glands. 
i. Ephidrosis; ii. Osmidrosis; iii. Chromidrosis; iv. Hse- 
midrosis; (6) Sebiparous Glands, i. Secretion increased ; 
Stearrhcea: S. Simplex, S. Flavescens, S. Nigricans, 
S. Cyanea; Ichthyosis; Cornua, ii. Secretion suppressed ; 
Zeroderma. iii. Secretion retained; Acne, Milium, Mol- 
luscum, Atheroma, (c) Lacteal Glands, i. Hypertrophy ; 
ii. Multiple glands ; iii. Galactirrhcea. 
5. Diseases of the Hair and Hair-follicles.—(a) Hairy noevi; 
(6) Alopsecia—i. Congenital; ii. Senile ; iii. Accidental; 
(c) Canities (Grey hair); (d) Albinismus; (e) Trichosis 
(Diseased hair); T. furfuracea; T. plica; (/) Trichiasis 
(Felting).