Eyelash trichomegaly is an unusual effect of this class of drugs, most frequently associated with cetuximab.³ We presente a case of a 68-year-old female patient undergoing treatment for metastatic colorectal cancer with panitumumab who developed elongation of the eyelashes and nasal hair (vibrissae).
Immunohistochemical evaluation suggested that the tumor originated in the gastrointestinal tract and had a staining pattern consistent with colorectal origin, although no apparent lesions had been detected during colonoscopy or other imaging tests, including CT-scan of the chest, abdomen and pelvis.
Palliative chemotherapy was indicated. Twelve cycles of a 6-month Folfox regimen (5-FU plus oxaliplatin) associated with targeted therapy with bevacizumab, a monoclonal antibody that blocks the action of vascular endothelial growth factor (VEGF), were chosen. Maintenance therapy was subsequently prescribed with the chemotherapy agent 5-Fluorouracil, from the class of antimetabolites. After 3 months of maintenance therapy, there was an increase in CEA tumor marker associated with an increase in peritoneal lesions. Treatment with Folfiri regimen (consisting of folinic acid, 5-Fluorouracil, and irinotecan) associated with panitumumab was then prescribed for 6 months.
At the beginning of panitumumab therapy, the patient developed skin toxicity with overgrowth of the eyelashes and nasal hairs (vibrissae) (Figure). Although it is not a severe or systemic adverse drug reaction, this side-effect caused cosmetic problems and discomfort to the patient and she was managed with eyelash trimming.
The patient had a good performance status, thus, continuous palliative care was indicated using palliative chemotherapy with panitumumab. She achieved a good response with control of cutaneous side-effects using prophylactic oral doxycycline, moisturizer, daily sunscreen, and topical hydrocortisone. The patient maintains regular follow-up visits with a dermatologist.