Alopecia
Introduction Hair loss (also called alopecia) may occur as thinning of the hair or shedding of hair , and is common in adults. It is often a cause of great concern to the patient for cosmetic and psychologic reasons. Hair Growth Cycle Hair loss disorders are usually due to the hair growth cycle being interrupted at different stages. During a person's lifetime, each follicle goes through many cycles of anagen, catagen and telogen . Anagen: A long (2- to 6-year) growing phase Catagen: A brief (3-week) transitional apoptotic phase Telogen: A short (2- to 3-month) resting phase At the end of the resting phase, the hair falls out. Normally, about 50 to 100 scalp hairs reach the end of resting phase each day and fall out. Classification Alopecia can be classified as focal or diffuse and by the presence or absence of scarring . Scarring (cicatricial) alopecia Is the result of active destruction of the hair follicle. The follicle is irreparably damaged and replaced by fibrotic tissue. In...