The ready reference hand-book of diseases of the skin

Front matter

Class Book

Wl^l

J

Preface

The aim of this book has always been to furnish students and practitioners with a comprehensive yet compact exposition of dermatology. The rate of growth of the subject is in a way reflected in some statistics of its increase in size. Its first edition in 1902 contained 502 pages discussing 164 diseases. In this edition there are 726 pages describing 257 diseases. In spite of liberal pruning, rewriting, and the elimination of anything obsolete, this new issue is 32 pages longer than its predecessor.

New sections have been added on acarodermatitis urticariodes, cutis verticis gyrata, eczema marginatum, eczematoid dermatitis, erythema figuratum perstans, gangosa, granuloma coccidioides, ground itch, hemisporosis, keratodermia gonorrhoica, leukemia cutis, lichenification, lichen nitidus, lichen planus sclerosus et atrophicus, and trypanosomiasis. Many of the old sections have been entirely rewritten.

The author acknowledges with thanks his indebtedness to his friends: Dr. M. F. Engman, for an article on Vaccines; to Dr. John A. Fordyce for one on Salvarsan; and to Dr. G. M. MacKee for one on the use of ar-rays. These gentlemen are so eminent in their respective fields that their contributions add greatly to the value of the

IV PREFACE

book. Hearty thanks are also due to Dr. H. Noguchi for pictures of Treponema pallida, and to Dr. H. Fox for some admirable photographs of cases.

To the medical public the author expresses his appreciation for the kindly reception accorded the previous editions of the book and the hope that it will continue to render acceptable service.

G. T. J. 11 East Forty-eighth Street, New York.

DISEASES OF THE SKIN.

Part I. General Considerations

Anatomy and Physiology of the Skin.

The skin varies in thickness in different regions of the body from J to 8 mm. It is composed of three distinct layers, namely : (1) the epidermis; (2) the derma, also named the cutis vera or corium; and (3) the subcutaneous connective tissue. At all the orifices of the body lined with mucous membrane, the latter and the skin merge into each other. The appendages of the skin are the hair, the nails, the sebaceous and the sweat glands. This complicated structure is supplied with bloodvessels, lymphatics, and nerves.

Epidermis. — The epidermis scarf skin, or cuticle, is composed of four layers, called strata, namely: (1) the stratum corneum; (2) the stratum lucidum; (3) the stratum granulosum; and (4) the stratum mucosum. Of these strata, the two that most concern us are the first and the last — that is, the stratum corneum and the stratum mucosum. The other layers of the skin may, for our present purpose, be regarded as simply transition-layers through which an epithelial cell passes on its developmental way to become a fully formed corneous cell. Each of the four strata of the epidermis 2 is divided again into layers, but these are of no practical importance. The thickness of the epidermis varies from 0.25 to 1.65 mm., being thickest and most compact

Fig. 1

Vertical section through the skin. Diagrammatic. (After Heitzmann.)

where it is subjected to the most pressure of intermittent character, as on the palms and soles.

The stratum corneum, or horny layer, consists of a series of superimposed layers of flattened, elongated cells that increase in flatness from below upward. The upper layers are called scales. The cells of each layer are united to each other so much closer than the layer itself is united to those above or below it that when an effusion takes place into the stratum corneum a layer of cells in the affected area is raised and the fluid is found between two layers. The lamellated scaling met with in certain scaly diseases, such as dermatitis exfoliativa, in which great plates of scales are readily removable, is likewise due to this close relation between the cells of each layer. This stratum is largely a protective one, its compactness affording a fair degree of resistance to injury of the underlying, more succulent layers of the epidermis.

The stratum mucosum, rete Malpighii, or mucous layer, is the deepest layer of the epidermis, and is seated upon the papillary layer of the corium. It is composed of several layers of cells, but may be considered as consisting of two chief layers, namely, the columnar epithelium and the prickle cells. The columnar epithelial cells are arranged perpendicularly to the papillae of the corium, while the prickle cells, which are polygonal in shape with spherical nuclei and with little filaments running out from their sides toward the neighboring cells, are arranged in strata over them. As the stratum granulosum, which lies above the stratum mucosum, is approached, the prickle cells become flatter, and finally lie with their long axis parallel to the general surface. The "granules" contain eleidin (Ranvier) and keratohyalin (Waldeyer), the former being a fluid and the latter a solid substance. The stratum mucosum is the most important stratum of the epidermis, and the seat of that most common of all skin diseases, eczema. From its lower part it sends down projections between the papillae of the corium, which are called interpapillary projections. Most of the pigment of the skin is situated in the lower part of the stratum mucosum. As the upper part is approached, less and less pigment is found. The pigment itself is in tl^e form of granules and of diffused coloring matter. According to Unna, the pigment is found even in the upper part of this layer, while in pathological conditions it may be located in the corium. In the so-called colored races pigment is always found in the corium, and even the horny layer is stained.

From this arrangement of the cells of the epidermis it will be seen that nutrient fluids can readily work upward from below by means of the little channels formed by the interlacing of the filaments running between the cells.

The epidermis has no bloodvessels. It receives its nutrition entirely from the corium. Though there are no true lymphatics in the epidermis, there are abundant lymph spaces between the cells that take their place. Nerves of the non-medullated variety have been traced between the cells of the epidermis, and have been described by some histologists as entering into the cells to end at the nucleus, though not to enter it. The final distribution of the nerves in the epidermis is not yet fully determined.

Corium. — The corium is composed of white fibrous and yellow connective tissue, disposed in horizontal bundles above and in oblique bundles below. It is a very dense and tough tissue, and is pierced in all directions to allow of the passage of bloodvessels, lymphatics, sweat ducts, and nerves, and affords lodgement for the hair follicles and sebaceous glands. It contains a considerable amount of elastic fibers, especially in regions such as about the joints where there is more or less motion. The upper part has been named the pars papillaris, and the lower part the pars reticularis corii. From its upper part it sends off a vast number of projections called papillw. These vary in length, being longest and most marked on the ends of the fingers and toes. The epidermis follows these projections and dips down between them. They are readily seen as parallel markings on the ends of the fingers. Over most of the body surface the papillae are but slightly raised, and merely give a wavy appearance to the upper edge of the corium when viewed under the microscope. As the lower part of the corium is reached the bundles of fibers are less closely crowded together, and becoming successively looser, gradually pass over into the —

Subcutaneous Connective Tissue. — This is a loose connective tissue with large and small spaces in it, which are filled with adipose tissue. This consists of fat cells collected into lobulated masses that in some cases have about them a connective-tissue sheath. Each lobule is supplied with an afferent artery, a capillary plexus about it, and efferent veins. This part of the skin is called the panniculus adiposus, and is found everywhere except in the skin of the penis, scrotum, labia minora, eye-lids, pinna, and beneath the nails. It contributes to the roundness and beauty of the body, besides acting as a store-house for fuel against such times as the body cannot gain its proper nutriment from food, as in fevers. It also gives lodgement to the coil or sweat glands, and aids in protecting the underlying parts from injury. The lower ends of the deep hair follicles are also in this part of the skin. The subcutaneous tissue merges into the underlying fasciae of the muscles and the periosteum of the bones. Under the name of columnce adiposce, J. C. Warren has described certain prolongations of fatty tissue running up to the bases of the hair follicles. They are important in relation to the pathology of carbuncle.

Bloodvessels. — The arteries which supply the skin come up from below to form a horizontal plexus in the subcutaneous tissue, from which the vessels proceed perpendicularly through the corium to form a second horizontal plexus just below the papillae. From the lower plexus small branches pass to the fat cells, sweat glands, and, according to Unna, the hair papillae. From the upper plexus branches are given off which enter the papillae of the skin. There are also branches to the hair follicles, sebaceous glands, and the tissue of the corium itself. Papillae that give lodgement to a tactile corpuscle have no arterial twig. The veins follow the same course as the arteries, but, of course, in the opposite direction.

Lymphatics. — Lymph vessels are large in the subcutaneous tissue, smaller in the upper part of the corium, and form plexuses. "Juice spaces/' filled with lymph, are found abundantly in the epidermis and papillae, about the glands of the skin, and around the muscles of the skin and the connective-tissue bundles and fat lobules.

Nerves. — The skin is provided with both medullated and non-medullated nerve-fibers and motor and vasomotor nerves. We have learned already that non-medullated nerve fibers have been traced between the cells of the epidermis, some terminating at, if not in, the nuclei of the prickle cells. It may be roughly stated that the nerves follow pretty much the same arrangement as the bloodvessels, forming a sort of plexus beneath the papillae and then giving off branches to the vessels, the tactile corpuscles, the papillae, the hair follicles, the sebaceous and sweat glands, and the epidermis.

The tactile corpuscles (corpuscles of Meissner) are located in the papillae. They are oval or rounded bodies, and their long axis runs longitudinally. Not more than one papilla in four is supplied with one of the corpuscles, even where they are most abundant — on the end of the index finger. They are composed, according to Unna, of large, flat connective-tissue cells, which are placed one above the other like coins in money rolls, and take up between them the terminal branches of the medullated nerves, which on entering the bodies lose their medulla and finally end between the cells. The transversely striped appearance presented by the corpuscles is due to the swollen lateral edges of the cells and the band-

CO

Hair Follicle and Shaft. (Darier.)

t. Shaft.

o. Follicle mouth, of funnel shape, co. Neck of follicle, tnu. Erector pili muscle, s. Sebaceous gland. r. Radicular portion of shaft or root, f. Connective-tissue sheath of follicle, ex. External epithelial layer, i. Internal epithelial layer.

i'. Internal epithelial layer, showing eleidine (keratohyalin) contained in the deeper portion, be. Bulb of hair shaft. The extremity is open and contains the papilla, p. Papilla.

g. Adipose tissue of the hypodermis. a Arteriole in cross-section. n. Nerve, be. Coils of sweat gland.

like nerve fibers that here and there appear upon the surface.

The corpuscles of Krause are located in the sensory mucous membranes. They are rounded in shape and bear a close resemblance to the Pacinian corpuscles in structure.

The Pacinian corpuscles are located in the subcutaneous tissues, and also in connection with the sensitive nerves. They are oval in form, visible to the naked eye, and consist in a colossal swelling-out of the sheath of Schwann, forming a thick connective-tissue capsule surrounding a much smaller cylindrical cavity filled with granular, faintly filamentous cellular substance, through the axis of which passes a sensitive nerve. As the latter enters the corpuscle it loses its medulla, and either terminates in the corpuscle or passes through it to enter one or more corpuscles. These corpuscles are most abundant in the fingers and toes, and the palms and soles. They are supposed to enable us to appreciate pressure or traction.

Less well understood are the MerheVs touch cells in the epidermis and corium. They are ovoid in shape with nucleus and nucleolus. Motor and vasomotor nerves are also found in the skin. The former are attached to the smooth muscles of the skin and glands; and the latter to the muscles of the vessel walls, and come into action in blanching and flushing of the skin.

Hair. — The hair is an epidermic structure which grows from a nipple-shaped projection, the hair papilla, situated at the bottom of a deep, slender pocket or saclike depression in the skin which is called the hair follicle. Commencing at the papilla it is bulb-shaped. This part is called the bulb and fits over the papilla like a cap. On leaving the papilla the body of the hair is first called the root, and then as it becomes narrower the shaft. The diameter of the shaft rapidly decreases until, leaving the skin, it terminates in the point. A fully formed hair is hollow, its central cavity being called the medullary canal and filled with the medulla. This is composed of

• a column of cells arranged in layers, one layer being superimposed on another. The main substance of the hair is called the cortex, and consists of long, spindle-shaped epithelial cells flattened out into fine bands which run in the long axis of the hair. This part of the hair gives it substance and strength, and in it is placed the pigment that determines the color of the hair. The outer layer of the hair is called the cuticle. It corresponds to the epidermis and consists of flattened, non-nucleated, fully cornified cells which cover the hair like scales and overlap each other like shingles.

The hair follicle is located, for the most part, in the corium, but in some very strong hairs it reaches down into the subcutaneous tissue. It is always, excepting at the dorsal edge of the eye-lids, placed at an angle to the skin, and is a permanent structure that is not removed when the hair is plucked. It is composed of three layers, which are derived from the corium as it dips down to form the follicle. Between the follicle and the hair is the root sheath, which is derived from the epidermis. It is composed of two layers, which are called the external and the internal root sheaths. The whole arrangement of the hair and its sheath may be graphically conceived by regarding the hair as a blunt needle pressed against the skin. The needle would form the hair, the epidermis would form the root sheath, and the corium would be to the outside of all and form the hair follicle.

Hair is found on all parts of the body excepting the palms and soles, the terminal phalanges of the fingers and toes, the glans penis, prepuce, labia minora, and the vermilion border of the lips. In form it is flattened or rounded, straight or curled. There are three main varieties of hair: (1) long, soft hair, as of the head and beard; (2) short, stiff hair, as of the eye-brows and eye-lashes; and (3) lanugo, or soft, downy, colorless hair, that is scattered all over the surface of the body.

Nails. — The nails, like the hair, are epidermic structures. They are placed on the extensor surfaces of the terminal phalanges of the lingers and toes. Their proximal end is called the root, under which is the matrix, from which they grow. On the way to their distal end they pass over the nail bed. This is separated from the matrix by a more or less convex and apparent line called the lunula. At their posterior and lateral margins they are embedded in a fold of skin that is called the nail fold. At their distal extremity they are separated from the end of the finger or toe. They are formed by the matrix, but in passing over the bed they receive a certain amount of nourishment from it, and their cells become rapidly cornified. They are slightly curved from side to side, being convex above and concave below, and are marked with fine lines. The flesh beneath the nail is the same as the skin in general, though without subcutaneous tissue. The nail takes the place of the corneous and granular layers of the skin. They are horny and transparent, and are composed of several layers. It has been estimated that it takes from one hundred and eight to one hundred and sixty-one days for a finger nail to grow from the lunula to the free edge, the rate of growth being more rapid in summer than in winter. It has been noted that in a case of fracture of a limb the nails of the fingers or toes may cease growing until the bone is well knit.

Sebaceous Glands (Fig. 1). — These glands are of the racemose variety, and are closely related to the hairs, from two to six being attached to each hair, emptying by their ducts into the upper third of the follicle. Each gland is composed of a number of acini that empty by a common duct. They are composed of a delicate, structureless capsule, the membrana propria, which continues along the duct to merge into the hair follicles. This is lined with large, although short, cubical or cylindrical epithelial cells arranged in one or two rows. These are continuous through the duct with the cylindrical cells of the outer root sheath of the hair and of the skin. The interior of the glands is filled with fatty secretion.

Around the glands passes the external layer of the hair follicle. These glands occur also on the vermilion border of the lips, the labia minora, and the glans penis and prepuce, though in these locations there are no hairs. They are not found on the palms, soles, or backs of the third phalanges of the fingers and toes.

The function of the sebaceous glands is to oil the hair and skin, thus rendering them soft and supple, and giving luster to the hair. This oily secretion, or sebum, is produced by the cells, which, as they reach the central part of the acini, undergo fatty degeneration. It is composed of fats, fatty acids, cholesterin crystals, debris of cells, and water. It is forced out of the glands by the constant production of new sebum. The glands are largest in the nose, cheeks, scrotum, mons veneris, labia, and about the anus. It is not settled whether the smegma is composed of exfoliated cells alone or mixed with sebaceous matter.

Sweat Glands (Fig. 1). — The sweat glands are simple coil glands that are located in the lower part of the corium and in the subcutaneous tissue. Their ducts ascend through the corium in a straight or wavy line to the interpapillary spaces, where they enter the epidermis. The cells lining the coil are simple cubical epithelial cells. These are seated upon muscular fibers; and a connective tissue, the membrana propria, comes outside of all. An abundant net-work of bloodvessels surrounds each gland and sends off branches to its interior. The glands are also richly supplied with nerves. The duct is made up of pavement epithelium upon the membrana propria. When the epidermis is reached the membrana propria is lost, and the further tract of the duct seems to be made by the sweat working its own channel up between the epidermic cells. The duct ends as a rounded aperture on the surface of the skin that is called a sweat pore. Unna teaches that the sweat produced by the coil glands is mixed with other elements while passing through the epidermis, so that the secretion

PHYSIOLOGY 27

that appears at the sweat pores is not the same as that which leaves the coils. He further teaches that the office of the coil glands is not to produce sweat, but to oil the skin. This theory still needs confirmation before it can be accepted as proved. His arguments have considerable weight, but space will not allow of their statement here. It has long been known that there was a certain amount of oil in the sweat. Sweat glands are most numerous in the palms and soles. Their diameter is from 0.3 to 0.4 mm. The largest are in the axilla, where they have a diameter of 2 to 7 mm., and are very numerous. In the external meatus of the ear they secrete the so-called ear wax.

Muscles. — The skin is provided with muscles, both of the striated and unstriated variety. The striated muscles are found in the face and neck. The majority of the muscles of the skin are involuntary muscles. In the scrotum they run parallel with the raphe. On the penis and about the nipple their direction is circular. The arrectores pilorum muscles are found all over the body, running in a more or less oblique direction from the bottom of several papilla? down and around a sebaceous gland to be attached to the bottom of a hair follicle. By contracting they raise the hairs to a perpendicular position and aid in pressing out the contents of the sebaceous glands.. There contraction also causes the appearance known as "goose flesh" when cold strikes the skin.

Physiology.

The skin is a protective, sensory, heat-regulating, and secretory organ. It offers protection to the deep parts by the pad-like structure of the subcutaneous tissue with its panniculus adiposus, and the highly resistant nature of the insensitive horny epidermis, both to physical and chemical agencies, and to the penetration of bacteria. The most vulnerable points in the skin are the pilosebaceous openings, and these are usually plugged with masses of sebum.

The end organs of touch and temperature sensation are located in the skin, but the delicacy of these sensations varies markedly in different regions. Loss of sensation leads frequently to the formation of traumatic lesions in the anesthetic area. Little is known about the existence of trophic nerves, although the nutrition of peripheral parts seem to be influenced by the central nervous system.

The skin plays a very important part in the regulation of the amount of heat lost by the body through evaporation, radiation, and conduction. In man 77 to 85 per cent, of the total heat loss of the body is through the skin. The regulation is effected through the blood supply and the sweat secretion. The efficiency with which the mechanism serves its purpose is evidenced by the fact that in a dry atmosphere a temperature of over 250° F. will not produce any change in the body temperature as long as the sweat secretion remains active. When the body surface is exposed to cold, the sweat secretion is reduced to a minimum and the skin blanched by the contraction of the cutaneous vessels, under the control of the vasomotor centre. The emptying of the vessels is assisted by the contraction of the involuntary muscles of the skin, which increase the tension and the pressure around the vessels, and produce the condition known as gooseflesh (cutis anserina) .

The sweat is 99 per cent, water, and varies in amount from 600 to 1300 c.c. a day, but may rise under stimulation as by heat or exercise even to 400 c.c. an hour. Besides its heat regulating function, it serves also to remove small quantities of excretives from the body and to keep pliable and moisten the epidermis.

The sebum, besides lubricating the skin, prevents the absorption of aqueous solutions from without, and the evaporation of fluids from within. It is always very difficult to make the skin absorb medicaments, and it is believed that such absorption takes place through the glandular orifices and mouths of the hair follicles.

Diagnosis.

The Lesions of the Skin. — We speak of primary and secondary lesions of the skin. By the first of these terms we mean the form assumed by the efflorescence at its first appearance. By the second of these terms we mean the subsequent changes the primary lesion undergoes of itself, or as the result of extraneous causes acting upon it. In running its course, whether influenced by treatment or not, almost every disease of the skin exhibits more than one lesion, and we can only speak of it as a macular, papular, or other disease from its most prominent and characteristic lesion.

The primary lesions of the skin are the macule, the papule, the tubercle, the vesicle, the pustule, the bulla, the wheal, and the tumor. The secondary lesions of the skin are the crust, the scale, the excoriation, the fissure, the ulcer, and the cicatrix. These may be graphically represented, following Piffard. 1

Primary Lesions. — A macule is a spot or stain of the skin which is not raised above its surface. It may be of any size from that of a pinpoint to that of the palm of the hand, or larger. Large-sized and diffused, nonelevated lesions are usually spoken of as patches. A macule is usually round, but may be of any shape. It may be white, red, brown, black, blue, pink, or yellow, according to its cause. It may be due to hyperemia, as in erythema simplex; to a change in the pigmentation of the skin, as in lentigo and chloasma, where there is increase of pigmentation, or in vitiligo, where there is decrease of pigmentation; to a hemorrhage into the skin,

1 Cutaneous Memoranda. Wood, N. Y., 1885.

as in purpura; to a development of bloodvessels in the skin, as in nevus vascularis and telangiectasis; to a parasitic growth in the skin, as in chromophytosis ; to a change in the consistency of the skin, as in morphea and xanthoma; or to the introduction of foreign matter, as in powder stains or tatoo marks.

Fig. 2

LESIONS OF THE SKIN.

Primary.

Macule —

Fig. 3

Secondary.

Vesicle

Pustule

Bulla

Wheal

Tumor

A

Crust

Scale

Excoriation

Fissure -

V

Ul(

Cicatri

XXX

The macule may be evanescent or permanent; may remain as a macule during its existence, or may give place to a papule, vesicle, or pustule. It is the simplest of all the lesions of the skin, and is met with as a primary lesion in many of its diseases.

The principal macular diseases are chloasma, chromophytosis, erythema simplex, lentigo, melasma, morphea, nevus simplex and spilus, purpura, scleroderma, vitiligo, and xanthoma.

A papule is a circumscribed, solid elevation of the skin. In size it varies from that of a pinpoint to that of a split pea. It may be of different colors, from white as in milium, to black as in melanotic sarcoma, but is usually some shade of red. It is soft or firm to the touch. In form it may be acuminated, rounded, flattened, or umbilicated. Its base may be round, oval, or angular. It may be due to inflammation, as in eczema; to hypertrophy of normal structures, as in verruca; to the heaping up of epidermic cells about a hair follicle, as in keratosis pilaris; or to the retention of sebaceous matter in a follicle, as in comedo and milium.

The papule may remain as such throughout its course, and finally be absorbed; or it may change into a vesicle or pustule; or it may soften and break down.

Papular diseases have received the name of lichenoid diseases, and at one time we had a goodly number of lichens. Most of these have now been placed under other headings, as it is recognized that they are but single manifestations of other diseases. Papular diseases may be scaly and itchy.

The principal papular diseases are lichen tropicus, lichen ruber acuminatus and planus, lichen scrofulosorum, lichen pilaris or keratosis pilaris, lichen urticatus or papular urticaria, acne, comedo, milium, prurigo, syphilis, and psoriasis. Like the macule, the papule is found in many diseases that cannot be classed as papular.

A tubercle or nodule may be thought of as a large papule. Like it, it is a circumscribed solid elevation of the skin, usually of a reddish color. Indeed, the difference between a papule and a tubercle is mainly arbitrary and for convenience. Thus we speak of a solid lesion up to the size of a split pea as a papule, while above that it is spoken of as a tubercle. Some lesions which are usually spoken of as tubercles, such as the tubercular syphilide, may not be larger than a split pea. Stelwagon makes the good suggestion that "a papule may be a solid lesion extending upward; a tubercle a solid lesion projecting both upward and downward." Quite commonly, when a lesion is larger than a cherry it is spoken of as a node. Auspitz 1 makes the distinction between a papule and tubercle on more scientific grounds, and regards a tubercle as a cell infiltration into the corium. A tubercle is not only larger than a papule, but it extends deeper into the skin. In form and color a tubercle corresponds to a papule.

Tubercles may be absorbed and disappear and leave no trace; or they may break down and ulcerate and leave scars, as in syphilis; or they may remain unchanged for an indefinite period, as in molluscum.

The principal tubercular diseases are: carbuncle, epithelioma, keloid, lupus vulgaris, molluscum, rhinoscleroma, and xanthoma. Tubercles form a very prominent symptom in leprosy, syphilis, and erythema multiforme. Of course, tubercular used in this sense has nothing to do with the tubercle of tuberculosis.