Hair Loss and Hedgehog Inhibitors: A Class Effect?

The article discusses the side effects of hedgehog pathway inhibitors, specifically vismodegib and sonidegib/erismodegib, which are used to treat advanced basal cell carcinomas. It reports on a series of 5 patients (4 females, 1 male, median age 51) treated with these drugs who experienced profound hair thinning and increased shedding, with a median onset of 3 months after starting treatment. The pattern of hair loss was diffuse and also affected body hair in four cases. Histopathological examination of scalp biopsies from 4 patients showed a non-scarring process with an increase in telogen hairs, consistent with telogen effluvium. One patient experienced hair regrowth after ceasing treatment, suggesting that the hair follicles may recover when the medication is stopped. The article suggests that alopecia is a class effect of hedgehog pathway inhibitors and emphasizes the importance of counseling patients about this side effect.