A young woman simultaneously developed erythema nodosum (EN) and serological signs of lupus erythematosus (LE) while taking an oral contraceptive. Both the EN and LE disappeared following cessation of medication, then recrudesced with reinstitution of therapy. Substitution of an anovulatory preparation, which differed from the original by only a single methyl group on the estrogen moiety, resulted in a marked diminution of the clinical signs of EN and a virtual disappearance of serological abnormalities. In vivo skin tests and in vitro lymphocyte-transformation studies utilizing the constituent hormones in the drug did not produce evidence of cellular hypersensitivity. In the absence of demonstrable hypersensitivity, the association of EN and LE indicates that immune complex may contribute to the pathogenesis of EN.
Elias PM. Erythema Nodosum and Serological Lupus ErythematosusSimultaneous Occurrence in a Patient Using Oral Contraceptives. Arch Dermatol. 1973;108(5):716-718. doi:10.1001/archderm.1973.01620260064027