skin, characterized by the eruption of prominent pustules, of a rounded form and considerable size, upon any part of the surface of the body. The pustules are usually discreet, they are developed on a hard and inflamed base, and terminate in dark-coloured crusts, which leave a deeply congested surface on their fall, and sometimes a superficial ulcer, followed by a cicatrix. The eruption is for the most part partial and successive; in rare instances it is general; in the former case it may endure for one or two weeks; in the latter, for several months. It is not contagious.

376. Ecthyma is endowed by Willan with four varieties, having relation to the constitution and age of the patient; these are, ecthyma vulgare, ecthyma infantile, ecthyma luridum, and ecthyma cachecticum. I prefer, however, with Rayer, to consider the disease as presenting an acute and a chronic type; the former of these divisions corresponding with the ecthyma vulgare, and the latter embracing the three remaining varieties. In a tabular form, the varieties of ecthyma are, Ecthyma acutum seu vulgare.

Ecthyma chronicum,

E. infantile,

E. luridum,

E. cachecticum.

ECTHYMA ACUTUM SEU VULGARE.

377. This eruption (PLATE 10, H.-N.) is most frequently seen upon the extremities, often on the shoulders and neck, but rarely on the scalp. Its development is indicated by the appearance of small, red, and circumscribed spots, which gradually rise above the surface, are hard and painful to the touch, and increase to a variable size. Upon the summit of each of these conical elevations, a small quantity of puriform fluid is effused beneath the epiderma, and the matter continues to be augmented by additional secretion, until a pustule is formed. The size of the pustule is various; usually it is as large as the half of a pea, and surrounded by a hardened base of vivid redness, while at other times it covers the whole extent of the hardened base, and resembles a bulla distended with pus. The development and growth of the pustule is accompanied by severe pain, which is frequently of the lancinating kind. In the course of three or four days after the completion of the pustule, the contained fluid dries up into a darkcoloured scab of various thickness, which falls off in a few days, leaving behind a congested circular spot, of a deep red colour. Sometimes the purulent fluid is removed by absorption, and the surface of the skin is restored to its natural state, after repeated desquamation. At other times a superficial ulcer is formed, particularly on the lower extremities, and terminates with a slight cicatrix. When the eruption of pustules has been numerous, the congested spots left by the fall of the crusts present a remarkable appearance.

Rayer gives so excellent an account of the structure of the pustules, during their progressive development, that I am tempted to quote his words.

"We find," writes this author, "1. that in their first stage

Translation by Willis, second edition, p. 530.

(red elevations) there is merely sanguineous injection with conical tumefaction of the corion; 2. that in the apex, more rarely over the whole surface of the elevations, and under the cuticle, there is an ef fusion of a certain quantity of purulent serum; 3. that in the third stage, which follows immediately after, there is a kind of pseudo-membranous matter deposited in the centre of the elevation, which is now evidently perforated; 4. that after the voidance of this matter, and the removal of the cuticle, the pustule appears under the form of a cup-shaped cavity, surrounded by a hard, thick, puffed edge; 5. lastly, that on the following days this thickened margin subsides, at the same time that a slight cicatrix is formed under the crust, the centre of which is fixed within the point where the perforation has been observed.

ECTHYMA CHRONICUM.

378. Chronic ecthyma (PLATE 10, H.-Q.) is a more common form of disease than the acute variety; it occurs in successive eruptions, generally in persons of debilitated and cachectic habit, and is prolonged

for several months.

When it appears in ill-fed, ill-clad, and weakly children, or in those who are debilitated from preceding disease, it constitutes that variety which has been designated by Willan, ecthyma infantile. This eruption is not unfrequently associated with irritation, or disease of the alimentary mucous membrane. The pustules are very dissimilar in point of size, some being small, and some large; they are circular in form, surrounded by an areola more or less inflamed, and terminate by absorption of the purulent fluid, and epidermal desquamation, or by ulceration. The ulcers in this disease are unhealthy, and difficult of cure.

In old persons, and in those who have injured their constitution by excess, the congested areolæ often present a purplish-red and livid colour; the pustules are of large size, and filled with a sanguinolent, puriform fluid, and they are remarkable for the tardiness of their course. This character of the eruption constitutes the ecthyma luridum (P. Q.) of Willan and Bateman.

In persons of unsound and cachectic constitution, of all ages, the cachectic form of eruption is developed. The pustules occur upon all parts of the body, but most frequently on the legs. The inflammation preceding the eruption is more extensive than in ecthyma acutum, and variable in degree. At the end of six or eight days, the epiderma is raised by the effusion of a small quantity of dark, sanguinolent pus, which forms by its increase an unhealthy and discoloured pustule. When the pustule is fully developed, the epiderma bursts, and the denuded surface becomes covered by a thick, dark-coloured crust, which appears enchased within the skin, and remains adherent for several weeks. If the crust be removed by accident or design, an ill-favoured ulcer with inflamed edges is exposed, which is tedious and difficult of

cure.

The pustules of ecthyma are not unfrequently associated with scabies, lichen, prurigo, and some other chronic affections of the skin.

379. Diagnosis. The large size and prominence of the pustules,

their inflamed bases, and the mode of their development, serve to distinguish ecthymna from all other pustular affections. When the pustules of acne and sycosis attain a large size, they bear some resemblance to ecthyma, but are easily distinguished by the broad and inflamed areola of the latter, and the hard, tubercle-like elevations without areolæ of both the former.

Syphilitic ecthyma is distinguished from the form at present under consideration, by the more chronic character of the eruption, the limited extent of the areola, its coppery hue, the blackness and concentric marking of the crust, and the presence of other signs of constitutional syphilis.

380. Causes.-Ecthyma may be developed at all periods of life, and at all seasons, but is principally observed in young persons and in the adult, and most frequently in the spring and autumn.

It may be excited by various stimuli applied to the surface of the skin, such as sugar, lime, salt, sulphur, &c. Grocers are liable to this eruption, from the irritation produced by the first of these substances, and bricklayers of the second. The manipulation of pulverulent substances of all kinds is apt to act as an exciting cause, and simple friction may give rise to the same consequences. The pustules following the irritation of tartarized antimony are ecthymatous; they are umbilicated, contain in their interior a false membrane, are very numerous, and succeeded by dark-coloured crusts.

Ecthyma is frequently excited by the irritation caused by other cutaneous diseases, as by variola, rubeola, scarlatina, herpes, prurigo, scabies, &c.

This eruption is often symptomatic of a disordered state of the system, as of some chronic affections of the viscera, or irritation of the gastro-intestinal, or uterine mucous membrane. It may also be induced by excess of mental or physical exertion, by bad and deficient food, want of proper clothing, residence in damp and unhealthy situations, want of cleanliness, debilitating causes of various kinds, excesses, and exposure to vicissitudes.

381. Prognosis.-The prognosis of ecthyma depends on the state of constitution of the patient rather than upon the eruption, which is in most cases an effect of disordered health. When the cause is external, and the form of the disease acute, the eruption seldom continues longer than two or three weeks; but the chronic affection may be prolonged for several months.

382. Treatment. In the acute variety of ecthyma, after the removal of the cause, some gentle laxative and alterative medicine with diluents and abstemious regimen is all that will be required. The best local application is the superacetate of lead, or oxide of zinc ointment, or if the inflammation be severe, sedative and emollient fomentations and water-dressing.

When the disease is symptomatic of visceral disturbance, the treatment must be directed to the organ affected; the abstraction of blood is sometimes useful; tonic medicines, preparations of iron; abstinence from stimulating food or drinks; the cold or tepid bath, succeeded by friction on the sound integument, &c. I have employed the iodide of

potassium with great benefit, in the bad state of health which accompanies ecthyma cachecticum. The ill-favoured ulcers sometimes left by the latter variety of the disease may be brought into good condition by water-dressing, and mild stimulants, such as a solution of the nitrate of silver, sulphate of zinc, supersulphate of alumina, chloride of lime, &c., or the weak nitric acid lotion, either with or without opium.

CHAPTER VI.

DEPOSITIVE INFLAMMATION OF THE DERMA.

383. By the term "depositive," which I have selected only in the absence of a more suitable word, I mean to express that condition of the inflamed membrane in which plastic lymph is exuded by the capillary rete into the tissue of the derma, so as to give rise to the production of small hard elevations of the skin, or pimples. In the preceding groups of diseases we have seen simple congestion of the papillæ of the derma, effusion of the serous portion of the blood on the surface of the derma, formation of pus on the surface of the derma; but in the alteration now under consideration there is no primary serous effusion, and no generation of pus. As far as my observation of the pathological characters of the present disease enables me to determine, there is capillary congestion and effusion of plastic lymph into the tissue of the derma, constituting a pimple of small size.1

384. The pathognomonic symptoms accompanying pimples correspond, moreover, with the supposition of such a pathological structure; they are accompanied by incessant itching, a sensation which may be explained by reference to the moderate degree of pressure produced upon the nervous plexus of the derma by the effused lymph, or, probably, by the distention of the neurilemma of the nerves by the more fluid parts of the lymph, so as to affect the nutrition of the nervous substance. Pruritus is unquestionably a degree of pain, but it is one of a mild kind, and such as we see for the most part in papular eruptions of the skin, or when the derma is returning to its natural state after inflammatory congestion of its tissue, or, again, when

[There has been much difference of opinion in regard to the pathological changes in a pimple or papula. Henle believes them to consist in an accumulation of inflammatory exudations in the papillæ of the skin. Rokitansky ascribes them to an inflammatory process, in which a product of inflammation is poured into the parenchyma of the corium, and into each of the papillary bodies, or into the deeper layers of the same. Rosenbaum, Lessing, Klenke and Hebra regard papulæ as originating in a morbid condition of the sebaceous glands. The researches of Simon accord greatly with those of Henle and Rokitansky; and lead him to believe that a papula is an inflammatory stasis in the vessels of the cutis, with an accumulation of fluid exudations in the tissue of that membrane. (Op. cit. s. 93.)]

foreign substances, such as scabs and crusts, effused fluids, parasitic animalcules, &c., lie in contact with the skin.

385. The diseases which are here characterized by the designation "Depositive inflammation of the derma," correspond with the order Papulæ, of Willan; and in this instance no difference of opinion exists among dermatologists as to the morbid affections admitted into the group. They are three in number-namely,

Strophulus.

Lichen.

Prurigo.

Rayer and Gibert remark that the above number might very properly be reduced to two; for that strophulus is nothing more than the lichen of young children and infants, while Alibert considers the whole under the single genus, Prurigo.

386. The definition given by Willan of the elementary form of papular affections admits of no improvement. A papula or pimple is "a very small and acuminated elevation of the cuticle (derma) with an inflamed base, very seldom containing a fluid, or suppurating, and commonly terminating in scurf." Papulæ terminate by resolution, generally with furfuraceous desquamation of the epiderma. The papulæ of strophulus have usually a greater elevation than those of lichen and prurigo. Some differences are perceived also in relation to colour; thus the pimples of strophulus may be either red or pale, those of lichen are always more or less red and inflamed, while the papulæ of prurigo scarcely differ in tint from the surrounding skin.

387. In the first edition of this work, I stated my belief that the precise element of the dermal system affected in the papular diseases was the papillæ of the skin. More recent and careful examinations have proved to me that this is not the case, but that the real seat of morbid change is the vascular boundary of the various excretory tubules of the skin; for example, the sudoriferous and sebiferous ducts, and hair-follicles. This fact being determined, we have an explanation of various of the phenomena which accompany the eruption; for example, the frequent perforation of the pimples by a hair, the formation of a thin scale upon the summit of the papule, the occasional appearance of a minute aperture in this situation, and the oozing of a transparent and colourless fluid from the same point. We can also better understand the provoking itching which is a symptom of the eruption, the obstruction which is offered to the escape of secretions, and the obstinacy of these disorders. The papulæ of prurigo are perfectly identical with the papule of lichen, the difference between them being, that the latter are generally acute in their course, while the former are always chronic. But there is an appearance of the skin in prurigo that must be familiar to all who are conversant with cutaneous diseases; an unevenness of surface, produced by numberless slight but broad elevations, separated from each other by the linear markings of the skin. Now these are the elevations which have been described by all dermatologists, not excluding myself, under the name of the broad and flat papule of prurigo. "Soft and smooth papulæ, somewhat larger and less accuminated than those of lichen, and seldom appearing red or inflamed, except from violent friction.