Imiquimod-induced hypertrophic lupus erythematosus-like reaction

Imiquimod is a topical immunomodulator that acts as an inducer of interferon (IFN)-a expression through Toll-like receptor (TLR)7 signaling with indications for the treatment of non-hyperkeratotic actinic keratosis of the face or scalp, superficial basal cell carcinoma (BCC), and external genital and perianal warts. Imiquimod is also used off-label for nodular BCC, cutaneous T-cell lymphoma, pyogenic granuloma, and melanoma. Imiquimod-induced lupus-like reactions have been reported. However, hypertrophic lupus erythematosus (HLE) is a rare variant of cutaneous lupus and imiquimod-induced hypertrophic lupus has not been reported to date. We report a case of local induction of a plaque that resembled HLE clinically and histologically in an 82-year old woman following topical treatment with imiquimod.