Panitumumab-induced trichomegaly in a patient with metastatic colorectal cancer: Case report and systematic literature review

The advent of targeted therapies, such as panitumumab, has significantly improved treatment outcomes for metastatic colorectal cancer (mCRC). However, these therapies can also induce unique side effects, including trichomegaly, characterized by the abnormal thickening, lengthening, and curling of eyelashes. We report the case of a 67-year-old male with metastatic colorectal cancer who developed trichomegaly following treatment with panitumumab. The patient was initially treated with FOLFOX (fluorouracil, leucovorin, and oxaliplatin) and bevacizumab, but received panitumumab after disease progression. Two months after starting panitumumab therapy, the patient exhibited significant elongation and curling of the eyelashes. Despite the discontinuation of panitumumab due to disease progression, the trichomegaly persisted. Panitumumab-induced trichomegaly, while not requiring discontinuation of treatment, can be persistent and may cause discomfort. Awareness and management of this side effect are essential, especially considering its potential impact on patients' quality of life. Future studies are needed to better understand the mechanisms and long-term implications of panitumumab-associated trichomegaly.