Erythema Nodosum.
Erythema nodosum (syn., dermatitis contusiformis) is an acute inflammatory affection characterized by the formation of variously-sized, roundish or ovalish, more or less elevated erythematous nodes. Febrile disturbance usually ushers in the eruption, often accompanied with gastric derangement, malaise, and rheumatic pains. The efflorescence appears rapidly, having special predilection for the arms and legs, particularly the tibial surfaces. The lesions vary in size, being rarely smaller than a cherry and often as large as an egg, and are ovalish or roundish in shape. They are reddish in color, with a bluish or purplish tinge, which becomes more decided as they grow older. Later, as they are disappearing, yellowish, greenish, and bluish coloration manifests itself, as in the case of a bruise. Not infrequently the lesions are hemorrhagic. When at its height a node has a shining, tense appearance, indicative apparently of beginning suppuration; this latter process, however, does not occur, absorption invariably taking place. Firm and hard at first, as they begin to decline they become softer. They are apt to appear in crops. The lesions are rarely present in large numbers, from five to twenty being the average; occasionally, however, they are much more numerous. The mucous membranes may, as in erythema multiforme, be invaded. They are tender and more or less painful, and are usually accompanied with a sense of burning. Lymphangitis is at times observed. At the end of two or three weeks the affection has usually run its course.
The causes of the disease are not known. It is closely allied to erythema multiforme, and by many observers is regarded as merely a manifestation of that disease. It is generally encountered in the spring and autumn months, and occurs most frequently in children and young persons. It is usually associated with rheumatic pains, and not infrequently with digestive derangement. It is not a common disease. It is regarded by Lewin as an angio-neurosis. According to Hebra, in most cases it is essentially an inflammation of the lymphatics. Bohn regards it as due to embolism of the cutaneous vessels giving rise to inflammatory infarctions. The process is an inflammatory oedema. There is considerable serous transudation, with some blood-corpuscles, and not infrequently with more or less hemorrhage. The lesions usually bear resemblance to bruises, abscesses, and gummata. The rosy hue, the apparently violent character of the process, the number, course, and situation of the lesions, will serve to distinguish it. The prognosis is favorable, as the affection tends to disappear in a few weeks, rarely lasting more than a month.
As spontaneous recovery results, treatment should be conservative. Rest, the more complete the better, sedative applications, as of lead-water and laudanum or of carbolic acid, with the use of saline laxatives and full doses of quinia, are the measures indicated. The diet should be regulated according to the case.
Urticaria.
Urticaria, hives, or nettlerash, is an erythematous affection characterized by the development of wheals of a whitish, pinkish, or reddish color, accompanied by stinging, pricking, and tingling sensations. The advent of the efflorescence is usually sudden; not infrequently symptoms of gastric derangement precede its appearance. The wheals are of variable size, shape, and color. Ordinarily they are of the size of a coffee-grain or bean, rounded or ovoidal in shape, and whitish, pinkish, or reddish in color. They occur isolated or in the form of patches caused by a coalescence of several lesions, and vary in elevation from half a line to several lines. Instead of the ovoidal or rounded form, the eruption may appear in streaks or irregularly-shaped patches. To the touch the lesions may be soft or firm.
The efflorescence disappears, as a rule, without leaving a trace. Pigment-stains are in some cases left which may be slow to disappear. Burning, tingling, stinging, and itching are prominent subjective symptoms. The individual lesions are fugacious, inclining to disappear at one part and to show themselves at another. They are more apt to appear on parts subjected to pressure by contact of clothes, although no region is exempt. No age is spared, but the disease, especially in its acute form, is more common in the young. Ordinarily, urticaria is an acute disorder, lasting a few hours to several days, in which time frequent exacerbations may take place. On the other hand, it may be chronic in the sense that relapses occur successively, the skin, in fact, rarely being entirely free of the lesions.
At times the wheals are peculiar as to formation or are complicated with another condition, and hence arise the so-called varieties of the disease. The most common of these is urticaria papulosa, which was formerly known as lichen urticatus. The lesions have the form of a papule with most of the characteristics of a wheal. They appear, as a rule, suddenly, and after a few hours or days gradually disappear; they rarely occur in numbers, and are generally scattered over the trunk and limbs, especially over the latter. They are intensely itchy, and hence their apices are usually excoriated and covered with blood-crusts. The itching usually becomes more marked toward night. This form of the affection is observed particularly in badly-nourished or in ill-cared-for young children. The occurrence of the disease in association with purpura, or as a complication of the latter, has given rise to the names urticaria hæmorrhagica and purpura urticans or urticata. The lesion is of a mixed character—purpuric and urticarial. Sometimes the wheal formation is of such a nature as to give rise to fluid exudation, producing a bulla; hence the name urticaria bullosa. In rare instances large walnut- or even egg-sized nodes or tumors are formed, constituting urticaria tuberosa, or giant urticaria.
The causes of urticaria are numerous. Two that are well known may be classed under the heads of external and internal irritants. Under the former may be mentioned stinging nettle, jelly-fish, caterpillars, fleas, bedbugs, and mosquitoes; among the latter, whatever produces gastric and intestinal derangements. These latter are responsible for most instances of acute urticaria. With some persons indulgence in certain articles of food, as fish, oysters, clams, crabs, lobsters, pork, strawberries, and similar articles, almost invariably calls forth the efflorescence. A number of medicinal substances, such as copaiba, cubebs, turpentine, valerian, chloral, salicylic acid, iodide of potassium, quinine, and others, taken internally, may provoke an attack. Malaria, functional and organic diseases of the uterus, a weak or irritable state of the nervous system, and impaired digestion are common causes of both the acute and chronic forms of the disease. Various nervous, hemorrhagic, and rheumatic diseases are also sometimes associated with urticaria. In fact, an irritation from disease of any internal organ, functional or organic in character, may give rise to the eruption.
Anatomically, a wheal is seen to be a more or less firm elevation, consisting of a circumscribed collection of semi-fluid material exuded into the upper layers of the skin. It has its seat for the most part in the papillary layer. The vaso-motor nervous system is probably the main factor in the production of the wheal. Dilatation following a spasm of the vessels results in effusion; in consequence, the overfilled vessels of the wheal are emptied by the pressure of the exudation, and the central paleness produced, while the pressed-back blood gives rise to the red border.