Dr. L. Brocq, of Paris, has observed four cases of localized and persistent erythema from the use of antipyrine. They occur in either round or oval plaques, occasionally of quite large size, even eight centimetres in diameter. They appear isolated and scattered here and there on the surface of the body, without symmetry and generally few in number. In the beginning, the color is reddish gray, and they are often accompanied by burning sensations. There is rarely actual pruritus; later they become indolent. The erythema disappears, little by little, leaving a brown pigmented spot, which after repeated eruptions, which always select the same spot, may become blackish brown. Sometimes small vesicles are formed, and nearly always there is lamellar desquamation on disappearance of the erythema. The plaques are quite distinctly outlined, and are sometimes associated with a distinct swelling of the skin. The pigmentation is the last to disappear; in the smaller plaques it is no longer observed after two or three weeks, if the drug be left off; in the larger ones it persists longer. If the drug be still continued, a new erythematous outbreak appears on the old sites with increase of pigmentation. In some cases the eruption may last from a month to six months.
J Cutan Genito-Urin Dis. March 1895;13:128-129.
Pritchard. FH. Localized and Persistent Erythema from Antipyrine. Arch Dermatol. 1995;131(3):371. doi:10.1001/archderm.1995.01690150137039