Enanthem in Patients With COVID-19 and Skin Rash

Discussion | Lysophosphatidic acids bind the P2Y5 receptor in the hair follicle epithelium and activate hair growth.5 In ARWH due to LIPH pathogenic variants, loss-of-function variants in LIPH lead to a deficiency of lysophosphatidic acids and insufficient activation of P2Y5. The present prospective interventional study suggests that minoxidil could be associated with improvements in hypotrichosis in ARWH owing to LIPH pathogenic variants. There appears to be a binary response to minoxidil, with one group responding better than the other. The data on causative pathogenic variants suggest that it is unrelated to the LIPH pathogenic variants. Among the 8 patients with ARWH due to LIPH pathogenic variants, 5 patients were unrelated, and the other 3 were from 1 family. All 3 members of the family were in the group responding better. Thus, we cannot exclude the possibility that the family had an unknown genetic modifying factor affecting the efficacy of minoxidil. We need to know more about the follicular pathology to understand the pharmacologic response to minoxidil.