Case Report: Diffuse Hypertrichosis in the Course of Hepatitis C Treatment by IFN-Alpha and Ribavirin

A 32-year-old man with hemophilia and hepatitis C experienced diffuse hypertrichosis (excessive hair growth) after being treated with interferon-alpha (IFN-α) and ribavirin for 6 months. Prior to treatment, the patient had no facial hair, but post-treatment, he observed significant hair growth on his torso, limbs, eyelashes, eyebrows, and scalp. The hypertrichosis was addressed with laser therapy. While hypertrichosis has not been previously reported in patients with hemophilia or viral hepatitis, and ribavirin is not known to induce hair growth, IFN-α is typically associated with hair loss in 10%-30% of patients. However, in this case, IFN-α is believed to be the probable cause of the hypertrichosis, marking the first reported case of diffuse hypertrichosis, as opposed to previously reported localized hypertrichosis of eyelashes or eyebrows. The mechanism behind IFN-α-induced hypertrichosis is unclear, but it may involve abnormalities in the cytokine network or mutations in IFN-α receptors, suggesting an idiosyncratic effect.