Pityriasis rubra; Generalized exfoliative dermatitis
Definition. A general, or often universal, inflammatory disease of the skin, accompanied by constitutional symptoms and characterized by intense redness, followed by profuse desquamation.
Symptoms. While there are several varieties of inflammation of the skin and universal scaling which might call for differentiation, the typical symptoms are fairly constant. There may be no prodromal symptoms, or there may be general feelings of malaise with gastric disturbances, chill, and other pyretic symptoms. A temperature of 101* to 104* F. has been observed, but it rarely continues. Redness, which may vary from a bright red to a violet hue, often begins about the flexor junctions of the extremities, but may appear on any or several parts at the same time. Within two days to three weeks it extends, meets new horizons accompanied by sensations of formication, itching tingling or tension. After a variable period, the skin assumes a dull color, and scales of various sizes form, being usually largest upon the back, where they may be an inch or two in their largest diameter, and smallest on the face, being of a branny nature. These appear to be formed by a rapid drying and separation of epidermic epithelia, which if they remain for a time attached at the center or margin, present a fluffy look, or, if the flakes are large, resemble plates of armor. Separation at the natural lines of the skin will give them a ribbed appearance. When detached, they resemble torn pieces of brownish tissue paper. They may be so extensive as to fill a pint or larger measure in twenty-four hours. After the scales are removed, the skin beneath appears smooth, dry or moist, but is soon recovered by scales. In fact, the continuous exfoliation is the most characteristic feature of the disease. When the palms, hands and soles of the feet become involved, the exfoliation occurs in large pieces or in casts like a glove. The appendages of the skin may suffer to a large degree with baldness and shedding of the nails. The earliest stages of this disease are not often seen by physicians, but they may present papular, vesicular, bullous or squamous lesions or they may follow, eczema, psoriasis, pemphigus, etc. (secondary exfoliative dermatitis). There may occur irritating fluid exudations from large or small vesicles, which are most likely to be situated on parts of the skin in contact, as beneath the breasts of women, the axillae, and the genitourinary region. These preliminary eruptions may be temporary, persistent or recurrent.
The disease begins as a rule in adult life. It may go on with varying remissions for years. The most favorable cases last for only a few weeks or months. As it pursues its course, special symptoms or complications are apt to appear. Itching may or may not be pronounced; the same may be said of heat or burning. There is always sensitiveness to cold. and, in the later stages, thickening and constriction may interfere with motion causing ectropion and similar, atrophies. Inflammation of the mucous membrane of the eyes, bronchi, stomach, and mouth frequently occurs. The urine may become over-acid, of high specific gravity, while renal and cardiac complications impair nutrition and lead to general debility and cachexia. Death may result from exhaustion, but frequently some diseases like pneumonia or pleurisy causes the end.
In the rarer form, pityriasis rubra (Hebra), the origin is obscure, the development more insidious, the scales finger, moisture is absent and the result is nearly always fatal. While the same general symptoms with dull red color and profuse though finger scaling occur, the exfoliation is continuous and there is atrophic thinning and contraction of the skin. Progressive weakness is the natural result, and some internal disease usually precipitates the fatal ending.
Etiology and Pathology. Males are nearly twice as liable to the diseases as females, and, while it may occur at any age, the disease usually occurs between the fortieth and sixtieth years of life. It is probably the result of acute toxemia or poisoning, but rheumatism and gout have been so commonly found as underlying factors that the view has become prevalent that the disease is a diathetic affection. Some cases seem to be of septic or parasitic origin. Association with or occurrence after eczema, psoriasis, lichen, tuberculosis, alcoholic poisoning, malaria, applications of chrysarobin, arnica, iodoform and mercury have caused these factors to be known as predisposing or exciting agents. The exact cause of pitryiasis rubra is unknown. While the histological investigation has shown the process to be a dermatitis, it has not determined whether this is primary or secondary to some disturbance in the central or peripheral nervous system. Hence it may be said that the pathological origin is obscure.