Cetuximab-Induced Hypertrichosis of the Scalp and Eyelashes

The document reports a case of cetuximab-induced hypertrichosis, an abnormal hair growth, in a 100-year-old man being treated palliatively for metastatic squamous cell carcinoma of the scalp. After three months of cetuximab therapy, the patient, who previously had androgenetic alopecia with a Norwood-Hamilton stage of 7, developed black-to-grey curly thick hair on the temporoparietal regions of the scalp, as well as trichomegaly (elongation of eyelashes) and eyebrow growth. This case is notable as it is the first reported instance of scalp hypertrichosis following cetuximab treatment and the first where the new hair was black-to-grey in a grey-haired patient. The document suggests that cetuximab, an epidermal growth factor receptor (EGFR) inhibitor, may alter the hair growth cycle and the architecture of keratinocytes in the root sheaths, leading to changes in hair color and texture. It raises the possibility that EGFR-blockade could be explored as a potential treatment for alopecia, although further research is needed to establish this.