Eyelash Trichomegaly Complicating Pembrolizumab for Colorectal Cancer

Pembrolizumab, an immune checkpoint inhibitor used for treating various cancers, can cause rare hair-related adverse events, including eyelash trichomegaly. This case report discusses a 63-year-old male with colorectal cancer who developed eyelash trichomegaly after two cycles of pembrolizumab. Despite discomfort, the patient continued treatment due to a complete radiologic response of his cancer. The case highlights the importance of clinicians being aware of such uncommon side effects for effective patient management.