HI Well come to HCM I really appreciate your concern, the underlying cause of hair fall need to be found out and most common is fungal infection, on tentative basis this can be given try with selenium Shampoo apply this on affected part prior to bath at least half an hour, the affected area may become black after some day, then comes to normal and hair falls stops, once the hair the hair fall stops then Minoxidile 5% can be tried, in such condition clinical observation would be much helpful, hope this information helps, take care.