DIAGNOSIS.—The diagnosis of a typical case of erysipelas is so simple that the nature of the malady is often recognized by those unskilled in such matters. It is difficult to mistake for any other affection the circumscribed, swollen, shining, and rosy-reddish patch of skin, accompanied by fever or marked malaise, with adenopathy of near glands, and often with a history of traumatism to which the origin of the disorder may be readily referred.
It is to be distinguished from dermatitis in its various forms (venenata, medicamentosa, phlegmonosa, suppurativa) by its characteristic features, and by the frequent absence in these inflammations of a febrile reaction and of a shining, rosy-red hue of the skin, and by the peculiarities described above of the elevated margin of the erysipelatous area.
Eczema, especially in its chronic erythematous forms, exhibited in the face of adults in middle and later life, is of much slower development, is productive of itching, is ill-defined in contour, and is not accompanied by fever.
Erythema in all its varieties is a purely hyperæmic affection and unaccompanied by fever. In erythema multiforme there is an exudative process by reason of which various papules, nodosities, and at times even bullæ, appear upon the surface. None of them, however, are accompanied by a diffused area of redness spreading at the periphery. All of its lesions are circumscribed, and rarely affect the face.
Pemphigus could only be mistaken for the form of erysipelas bullæ, but its lesions do not rise from a broadly inflamed area; they rather have attended with each a distinct individual halo when the integument from which they spring is at all congested. They are also rarely accompanied by a febrile process.
Scarlatina, though a febrile affection, is readily distinguished from erysipelas by the appearance of its exanthem, symmetrically and generally developed over the entire surface of the body, or progressively and symmetrically from the upper to the lower segment of it. The exanthem has also a dull scarlet color or the boiled lobster hue, differing thus from the rosy-red and shining patch of erysipelas.
Urticaria also is often of symmetrical development, is rarely accompanied by fever, and is characterized by typical wheals, which, however closely packed together, never have the smoothness of the surface affected with erysipelas.
PROGNOSIS.—The prognosis of a simple case of uncomplicated erysipelas occurring in an individual in fair health and possessed of a reasonable degree of vigor may be regarded as favorable. Even in the weakness of infancy a large area may be involved in the disease and a high degree of fever be aroused without alarming results.
Erysipelas should, however, always be regarded as a serious disease or a serious complication of any existing malady. It is often a grave feature in surgical injuries. Erysipelas involving the entire surface of the face and head is always a formidable affection. In the puerperal state it is dreaded by every accoucheur.
All these circumstances are rendered more portentous by the existence of the disorder as a complication of any other grave malady, or by its occurrence among the subjects of alcoholism, struma, phthisis, or various other cachexias, and among the aged. Occurring in epidemic form among the inmates of prisons, camps, and hospitals, the mortality of the disease may be increased tenfold.