Erythema Multiforme, in which many of the lesions have become bullous—
Erythema Bullosum.
What type of the eruption is most common?
The papular, appearing usually upon the backs of the hands and forearms, and not infrequently, also, upon the face, legs and feet. The papules are usually pea-sized, flattened, and of a dark red or violaceous color.
Describe the various shapes which the erythematous lesions may assume.
Often the patches are distinctly ring-shaped, with a clear centre— erythema annulare; or they are made up of several concentric rings, presenting variegated coloring—erythema iris; or a more or less extensive patch may spread with a sharply-defined border, the older part tending to fade—erythema marginatum; or several rings may coalesce, with a disappearance of the coalescing parts, and serpentine lines or bands result—erythema gyratum.
Does the eruption of erythema multiforme ever assume a vesicular or bullous character?
Yes. In exceptional instances, the inflammatory process may be sufficiently intense to produce vesiculation, usually at the summits of the papules—erythema vesiculosum; and in some instances, blebs may be formed—erythema bullosum. A vesicular or bullous lesion may become immediately surrounded by a ring-like vesicle or bleb, and outside of this another form; a patch may be made up of as many as several such rings—herpes iris. In the vesicular and bullous cases the lips and the mucous membranes of the mouth and nose also may be the seat of similar lesions.
What is the course of erythema multiforme?