Discoid Lupus Erythematosus Lesions Associated with Systemic Fluorouracil Agents: A Case Report and Review

Systemic fluorouracil agents include not only 5-fluorouracil (5FU), but also capecitabine, tegafur, and uracil/tegafur (UFT). Systemic lupus erythematosus (SLE), subacute cutaneous lupus erythematosus (SCLE), and discoid lupus erythematosus (DLE) are subtypes of lupus erythematosus; drug-induced lupus erythematosus can also present in each of these subtypes. This report describes the case of a 65-year-old woman with systemic 5FU-induced DLE. Fluorouracil agent-induced DLE lesions occurring after initiating treatment with either systemic 5FU or its prodrugs have been described in 19 individuals (Including the woman in this report) in the literature: tegafur (10 patients), UFT (six patients), systemic 5FU (two patients), and capecitabine (one patient). The mean duration before the appearance of the DLE lesions on sun-exposed areas was 232 days after beginning the fluorouracil agent; however, the much earlier (three weeks) appearance of the DLE lesions after starting systemic 5FU in the women described in this report may have occurred since there was no delay associated with the conversion of a precursor drug to 5FU. Within two months (mean: 36 days) after stopping the fluorouracil agent, the DLE lesions resolved in 95% of the patients. Laboratory studies were only performed on some of the patients. None of the patients tested had antibodies to Ro/Sjogren’s syndrome A (Ro/SSA) and La/Sjogren’s syndrome B (La/SSB). The antinuclear antibody (ANA) titer was elevated in 71% of the tested individuals and decreased in all of the patients who were evaluated after the causative drug was discontinued. The pathogenesis for fluorouracil agent drug-induced DLE remains to be definitively established.