What is acute-circ.u.mscribed [oe]dema?

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 [oe]dematosa_, _acute_ _circ.u.mscribed [oe]dema_, _angioneurotic [oe]dema_).

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 [oe]dematous 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 "sh.e.l.l-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 a.s.sociated 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 circ.u.mscribed 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, a.r.s.enic, pilocarpine, _atropia_, pota.s.sium 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 circ.u.mscribed [oe]dema 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:--

[Rx] Acidi carbolici, ..................... [dram]j-[dram]iij Acidi borici, ........................ [dram]iv Glycerinae, ........................... f[dram]j Alcoholis, ........................... f[Oz]ij Aquae, ................................ f[Oz]xiv. M.

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

Urticaria Pigmentosa.

(_Synonym:_ Xanthelasmoidea.)

Describe urticaria pigmentosa.

Urticaria pigmentosa is a rare disease, variously viewed as an unusual form of urticaria and as an urticaria-like eruption in which there is an element of new growth in the lesions. It begins usually in infancy or early childhood and continues for months or years, and is characterized by slightly, moderately, or intensely itchy, wheal-like elevations, which are more or less persistent and leave yellowish, orange-colored, greenish or brownish stains. Exceptionally subjective symptoms are almost entirely absent. Anatomical studies show that the lesion has in some respects the structure of an ordinary wheal, with [oe]dema and pigment deposit in the epidermal portion, and cellular infiltration made up princ.i.p.ally of mast-cells.

[Ill.u.s.tration: Fig. 13.

Urticaria Pigmentosa.]

The nature of the disease is obscure and treatment unsatisfactory.

Ordinarily as early youth or adult life is reached it spontaneously disappears. The treatment advised is usually on the same lines as that of chronic urticaria.

Dermat.i.tis.

What is implied by the term dermat.i.tis?

Dermat.i.tis, or inflammation of the skin, is a term employed to designate those cases of cutaneous disturbance, usually acute in character, which are due to the action of irritants.

Mention some examples of cutaneous disturbance to which this term is applied.

The dermatic inflammation due to the action of excessive heat or cold, to caustics and other chemical irritants, and to the ingestion of certain drugs.

What several varieties are commonly described?

Dermat.i.tis traumatica, dermat.i.tis calorica, dermat.i.tis venenata, and dermat.i.tis medicamentosa.

Describe dermat.i.tis traumatica.

Under this head are included all forms of cutaneous inflammation due to traumatism. To the dermatologist the most common met with is that produced by the various animal parasites and from continued scratching; in such, if the cause has been long-continued and persistent, a variable degree of inflammatory thickening of the skin and pigmentation result, the latter not infrequently being more or less permanent. The inflammation due to tight-fitting garments, bandages, to constant pressure (as bed-sores), etc., also ill.u.s.trates this cla.s.s.