Folliculitis decalvans associated with erlotinib

Conflict of interest: none declared. A 60‐year‐old woman with metastatic non‐small cell lung cancer presented with hair loss. She had been using erlotinib (Tarceva™; Roche Netherland bv, Woerden, the Netherlands) 150 mg/day for 6 months. She reported a mild ‘acne‐like’ rash on her face and trunk that resolved spontaneously, but after this she noticed that her scalp was painful, and this was accompanied by the hair loss. She denied scratching or otherwise manipulating the affected area. There had been no response to mometasone fuorate 0.1% lotion. On physical examination, marked erythema, pustules crusts were seen on the scalp, with scarred patches of alopecia containing hair tufts (Fig. 1a). Histological examination of a biopsy taken from the scalp found ruptured and merging hair follicles, with a dense perifollicular infiltrate of plasma cells (Fig. 1b). Neutrophils formed pustules in the follicular infundibula and ostia. Bacterial and fungal stains were negative, but Staphylococcus aureus (tetracycline‐sensitive) was cultured from a pustule.