The Dark Side of Gefitinib: Reflectance Confocal Microscopy Applied to Hair Hyperpigmentation.

Gefitinib is a multi-target tyrosine kinase inhibitor used for the treatment of non-small cell lung cancer. Papulo-pustular and/or paronychia, abnormalities in hair growth, itching, and dryness due to epidermal growth factor inhibitors - i.e., PRIDE Complex - are a common effect of tyrosine kinase inhibitors. We report a case of hair and eyebrow hyperpigmentation after 7 months of treatment with gefitinib. In the literature, we found no data regarding rapid pigmentation of hair due to treatment with any multi-target tyrosine kinase inhibitors. To our knowledge, this is the first case reporting both hair and eyebrow hyperpigmentation. We hypothesize the role of different mechanisms linked to rapid hair hyperpigmentation.