Localized hair loss may be sub-divided into Scarring and Non-Scarring types. Alopecia Areata is a genetic, auto-immune disease that typifies the Non-scarring type. It manifests itself with the sudden onset of round patches of hair loss associated with normal skin and can be treated with local injections of Cortico-steroids. Fungal infections can cause hair loss in children. Scarring Alopecia can be caused by a variety of medical or dermatological conditions such as Lupus and Lichen Planus, or local radiation therapy. Baldness from injuries, or from local medical problems that have been cured, is usually amenable to hair transplantation. Traction Alopecia is the hair loss that occurs with constant tugging on the hair, in some beauty treatments.
Contrary to popular belief, dandruff usually does not cause hair loss. Like wise, type of water, frequent shampooing, oiling the scalp do not affect hair growth at all. Various shampoos which claim to make the hair grow have no basis.