Folliculitis-perifolliculitis related to erlotinib therapy spares previously irradiated skin.

Erlotinib, a specific epidermal growth factor receptor tyrosine kinase inhibitor, is used to treat various metastatic cancers. It is known to cause an acneiform rash. Herein, we report a case where the rash spared the previous radiotherapy field. A limitation of this study is that it is an anecdotal case report. Further research into the pathologic process of the rash is warranted to understand the reason for its absence in the irradiated skin.