Читать книгу Essentials of Diseases of the Skin - Henry Weightman Stelwagon - Страница 38

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(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 pricking 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 pronounced 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 factitia, 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).

Fig. 12.

Dermatographism. (After C.N. Davis.)

Are subjective symptoms always present in urticaria?

Yes. Itching is commonly a conspicuous symptom, although at times pricking, stinging or a feeling of burning constitutes 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 associated, hence the varieties known as urticaria papulosa, urticaria hæmorrhagica, 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 hæmorrhagica.

Urticaria hæmorrhagica 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).

What is acute-circumscribed œdema?

In rare instances there occurs, along with the ordinary lesions of the disease or as its sole manifestation, sudden and evanescent swelling of the eyelids, ears, lips, tongue, hands, fingers, or feet (urticaria œdematosa, acute circumscribed œdema, angioneurotic œdema). One or several of these parts only may be affected at the one attack; in recurrences, so usual in this variety, the same or other parts may exhibit the manifestation.

(These œdematous swellings occurring alone might be looked upon, as they are by most observers, as an independent affection, but its close relationship to ordinary urticaria is often evident.)

Describe urticaria bullosa.

Urticaria bullosa is a variety in which the inflammatory action has been sufficiently great to give rise to fluid exudation, the wheals resulting in the formation of blebs.

What is the etiology of urticaria?

Any irritation from disease, functional or organic, of any internal organ, may give rise to the eruption in those predisposed. Gastric derangement from indigestible or peculiar articles of food, intestinal toxins, and the ingestion of certain drugs are often provocative. The so-called “shell-fish” group of foods play an important etiological part in some cases. Idiosyncrasy to certain articles of food is also responsible in occasional instances. Various rheumatic and nervous disorders are not infrequently associated with it, and are doubtless of etiological significance. External irritants, also, in predisposed subjects, are at times responsible.

What is the pathology of urticaria?

Anatomically a wheal is seen to be a more or less firm elevation consisting of a circumscribed or somewhat diffused collection of semi-fluid material in the upper layers of the skin. The vasomotor nervous system is probably the main factor in its production; dilatation following spasm of the vessels results in effusion, and in consequence, the overfilled vessels of the central portion are emptied by pressure of the exudation and the central paleness results, while the pressed-back blood gives rise to the bright red periphery.

From what diseases is urticaria to be differentiated?

From erythema simplex, erythema multiforme, erythema nodosum, and erysipelas.

Mention the diagnostic points of urticaria.

The acuteness, character of the lesions, their evanescent nature, the irregular or general distribution, and the intense itching.

What is the prognosis in urticaria?

The acute disease is usually of short duration, disappearing spontaneously or as the result of treatment, in several hours or days; it may recur upon exposure to the exciting cause. The prognosis of chronic urticaria is to be guarded, and will depend upon the ability to discover and remove or modify the predisposing condition.

What systemic measures are to be prescribed in acute urticaria?

Removal of the etiological factor is of first importance. This will be found in most cases to be gastric disturbance from the ingestion of improper or indigestible food, and in such cases a saline purgative is to be given, probably the best for this purpose being the laxative antacid, magnesia; or if the case is severe and food is still in the stomach, an emetic, such as mustard or ipecac, will act more promptly. Alkalies, especially sodium salicylate, and intestinal antiseptics are useful. Calcium chloride in doses of five to twenty grains should be tried in obstinate cases. The diet should be, for the time, of a simple character.

What systemic measures are to be prescribed in chronic and recurrent urticaria?

The cause must be sought for and treatment directed toward its removal or modification. Treatment will, therefore, depend upon indications. In obscure cases, quinine, sodium salicylate, arsenic, pilocarpine, atropia, potassium bromide, calcium chloride, and ichthyol are to be variously tried; general galvanization is at times useful, as is also a change of scene and climate. A proper dietary and the maintenance of free action of the bowels, preferably, as a rule, with a saline laxative, is of great importance in these chronic cases.

In acute circumscribed œdema treatment is essentially that of urticaria, the diet being given special attention.

What external applications would you advise for the relief of the subjective symptoms?

Cooling lotions of alcohol and water or vinegar and water; lotions of carbolic acid, one to three drachms to the pint; of thymol, one-fourth to one drachm to the pint of alcohol and water; of liquor carbonis detergens, one to three ounces to the pint of water, or the following:—

℞ Acidi carbolici, … … … … … … … … … … … ʒj-ʒiij

Acidi borici, … … … … … … … … … … … … ʒiv

Glycerinæ, … … … … … … … … … … … . … . fʒj

Alcoholis, … … … … … … … … … … … . … . f℥ij

Aquæ, … … … … … … … … … … … … … … f℥xiv. M.

Alkaline baths are also useful, and may advantageously be followed by dusting-powders of starch and zinc oxide.