الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Alopecia areata (AA) is a disease characterized by non scarring hair loss on the scalp or any hair-bearing surface. A clinical presentation of AA can occur from a single patch of hair loss to complete loss of hair on the scalp (alopecia totalis) or the entire body (alopecia universalis). AA in severe or chronic cases may cause psychological and emotional distress for affected individuals.
Although exact pathogenesis of alopecia areata remains undetermined, most evidence supports AA is an autoimmune disease. Alopecia areata is associated with other autoimmune conditions, such as thyroid disease and vitiligo.
The treatment of alopecia areata continues to be difficult. Many therapeutic modalities have been used to treat alopecia areata, like minoxidil, corticosteroids, sulfasalazine, azathioprine and topical immunotherapy. None of these agents are curative or preventive. Also many of these therapeutic agents have not been subjected to randomized, controlled trials. So, these forms of therapy are unsatisfactory.
Superficial hypothermic cryotherapy with liquid nitrogen appears to promote hair growth in AA, liquid nitrogen therapy may improve blood circulation within hair follicles, the improved blood circulation promoting topical nutrition and acceleration of hair regrowth, so cryotherapy is one of therapies for treatment of alopecia areata.