Scanning Electron Microscopy of Erlotinib-induced Hair Changes: Pili Torti et Canaliculi

The cutaneous toxicity of the epidermal growth factor receptor inhibitors, such as erlotinib, is associated with a wide range of manifestations, such as papulopustular eruptions, xerosis, paronychia, and changes in the growth pattern of hair and nails. Hair manifestations are seen in 10%–20% of the patients. A female patient taking erlotinib for lung cancer for 8 months noticed that her scalp hair became rough on palpation and that her eyelashes were elongated. Some scalp hairs were cut and proximal and distal portions were examined in natura with scanning electron microscopy. Torsions and important grooving were seen in the proximal portions, but not in distal hair portions. Erlotinib-induced hair changes are pili torti et canaliculi.