[A case of cutaneous vasculitis caused by erlotinib treatment and a review of literature].

Erlotinib is a potent drug used for treating epidermal growth factor receptor (EGFR) mutation positive lung cancer. In this study, we report a case of erlotinib induced cutaneous vasculitis. The patient was a 69-year-old woman with a history of left lower lobe resection for lung cancer. Two years after the resection, she had metastasis in the adrenal glands for which we initiated erlotinib therapy at a dose of 150 mg/day. The patient developed multiple purpurae with a partially necrotic region on both lower thighs at 8 weeks after initiating therapy. The skin biopsy results revealed cutaneous vasculitis. We stopped erlotinib therapy after this diagnosis because of this adverse effect as well as because it exacerbated the cancer. The patient's skin manifestation disappeared 2 weeks after stopping therapy, with no recurrence of any symptoms of systemic vasculitis. We reviewed the literature on drug-induced vasculitis due to oral EGFR inhibitors and found 13 such cases. In most cases, the symptoms appeared 1-2 months after initiating therapy. In all the cases, the symptoms resolved within 2-6 weeks after stopping drug therapy. Erlotinib-induced cutaneous vasculitis is rare but may cause fatal systemic vasculitis. Therefore, the skin of patients who are undergoing erlotinib therapy should be carefully examined at regular intervals during the course of therapy for drug-induced adverse effects.