Erlotinib-induced scalp perifolliculitis

Erlotinib is a highly specific epidermal growth factor receptor tyrosine kinase inhibitor used to treat various metastatic cancers. The most commonly reported side effects in patients receiving erlotinib are dermatitis and diarrhea. The authors present two cases of erlotinib-induced severe scalp perifolliculitis, which is an adverse reaction that has not been reported to date. Both patients developed pustules and thick yellow-green crusted plaques on the scalp within weeks of starting treatment with erlotinib for metastatic non-small cell lung carcinoma. Skin biopsies revealed a perifollicular accumulation of inflammatory cells, lymphocytes, and neutrophils. Both patients were treated with oral doxycycline and achieved complete resolution within 2 to 3 weeks and no recurrence despite continuing the epidermal growth factor receptor tyrosine kinase inhibitor. This is a unique presentation of an erlotinib-induced skin eruption.