Essentials of Diseases of the Skin Part 10

What is known in regard to the etiology?

The affection is closely allied to erythema multiforme, and is, indeed, by some considered a form of that disease. It occurs most frequently in children and young adults, and usually in the spring and autumn months.

Intestinal toxins are thought responsible in some cases. Digestive disturbance and rheumatic pain and swellings are often a.s.sociated with it. By many the malady is thought to be a specific infection.

What is the pathology of erythema nodosum?

The disease is to be viewed as an inflammatory [oe]dema, probably resulting, in some instances at least, from an inflammation of the lymphatics or an embolism of the cutaneous vessels.

What diseases may erythema nodosum resemble?

Bruises, abscesses, and gummata.

How are the lesions of erythema nodosum to be distinguished from these several conditions?

By the bright red or rosy tint, the apparently violent character of the process, the number, situation and course of the lesions.

State the prognosis of erythema nodosum.

Favorable, recovery usually taking place in ten days to several weeks.

State the treatment to be advised in erythema nodosum.

Rest, relative or absolute, depending upon the severity of the case, and an unstimulating diet; internally intestinal antiseptics, quinin and saline laxatives, and locally applications of lead-water and laudanum.

Erythema Induratum.

(_Synonym:_ Erythema induratum scrofulosorum.)

What do you understand by erythema induratum?

A rare disease characterized in the beginning by one or more usually deep-seated nodules, and, as a rule, seated in the legs, especially the calf region. The nodules gradually enlarge, the skin becomes reddish, violaceous or livid in color. Absorption may take place slowly, or the indurations may break down, resulting in an indolent, rather deep-seated ulcer, closely resembling a gummatous ulcer. The disease is slow and persistent, and is commonly met with in girls and young women, usually of strumous type. It suggests a tuberculous origin.

Treatment consists in administration of cod-liver oil, phosphorus and other tonics. Rest is of service. Locally antiseptic applications, and support with roller bandage are to be advised.

Urticaria.

(_Synonyms:_ Hives; Nettlerash.)

Give a definition of urticaria.

Urticaria is an inflammatory affection characterized by evanescent whitish, pinkish or reddish elevations, or wheals, variable as to size and shape, and attended by itching, stinging or p.r.i.c.king sensations.

Describe the symptoms of urticaria.

The eruption, erythematous in character and consisting of isolated pea or bean-sized elevations or of linear streaks or irregular patches, limited or more or less general, and usually intensely itchy, makes its appearance suddenly, with or without symptoms of preceding gastric derangement. The lesions are soft or firm, reddish or pinkish-white, with the peripheral portion of a bright red color, and are fugacious in character, disappearing and reappearing in the most capricious manner.

In many cases simply drawing the finger over the skin will bring out irregular and linear wheals. In exceptional cases this peculiar property is so p.r.o.nounced and constant that at any time letters and other symbols may be produced at will, even when such subjects are free from the ordinary urticarial lesions (_urticaria fact.i.tia_, _dermatographism_, _autographism_).

The mucous membrane of the mouth and throat may also be the seat of wheals and urticarial swellings.

What is the ordinary course of urticaria?

Acute. The disease is usually at an end in several hours or days.

Does urticaria always pursue an acute course?

No. In exceptional instances the disease is chronic, in the sense that new lesions continue to appear and disappear irregularly from time to time for months or several years, the skin rarely being entirely free (_chronic urticaria_).

[Ill.u.s.tration: Fig. 12.

Dermatographism. (_After C.N. Davis._)]

Are subjective symptoms always present in urticaria?

Yes. Itching is commonly a conspicuous symptom, although at times p.r.i.c.king, stinging or a feeling of burning const.i.tutes the chief sensation.

In what way may the eruption be atypical?

Exceptionally the wheals, or lesions, are peculiar as to formation, or another condition or disease may be a.s.sociated, hence the varieties known as urticaria papulosa, urticaria haemorrhagica, urticaria tuberosa, and urticaria bullosa.

Describe urticaria papulosa.

Urticaria papulosa (formerly called _lichen urticatus_) is a variety in which the lesions are small and papular, developing usually out of the ordinary wheals. They appear as a rule suddenly, rarely in great numbers, are scattered, and after a few hours or, more commonly, days gradually disappear. The itching is intense, and in consequence their apices are excoriated. Sometimes the papules are capped with a small vesicle (vesicular urticaria). It is seen more particularly in ill-cared for and badly-nourished young children.

Describe urticaria haemorrhagica.

Urticaria haemorrhagica is characterized by lesions similar to ordinary wheals, except that they are somewhat hemorrhagic, partaking, in fact, of the nature of both urticaria and purpura.

Describe urticaria tuberosa.

In urticaria tuberosa the lesions, instead of being pea- or bean-sized, as in typical urticaria, are large and node-like (also called _giant urticaria_).