Mechanism of action: Topical immunotherapy acts by varied mechanisms of action. The most important mechanism is a decrease in CD4 to CD8 lymphocyte ratio which changes from 4:1 to 1:1 after contact immunotherapy. A decrease in the intra-bulbar CD6 lymphocytes and Langerhan cells is also noted. Happle et al, proposed the concept of ‘antigenic competition’, where an allergic reaction generates suppressor T cells that non-specifically inhibit the autoimmune reaction against a hair follicle constituent. Expression of class I and III MHC molecules, which are normally increased in areas affected by alopecia areata disappear after topical immunotherapy treatment 34 .A ‘cytokine inhibitor’ theory has also been postulated 34 .
Androgenic Alopecia - Androgenetic
Androgenetic alopecia In men, or male pattern baldness, is recognized increasingly as a physically and psychologically harmful medical condition. Androgenetic alopecia affects at least half of white men by the age of 50 years. Although androgenetic alopecia does not appear to cause direct physical harm, hair loss can result in physical harm because hair protects against sunburn, cold, mechanical injury, and ultraviolet light. Hair loss also can psychologically affect the balding individual and can Influence others' perceptions of him. A progressive condition, male pattern baldness is known to depend on the presence of the androgen dihydrotestosterone - DHT - and on a genetic predisposition for this condition. Medicines, hair transplantation, and cosmetic aids have been used to manage male pattern baldness. Two US Food and Drug Administration-approved hair-loss drugs - the potassium channel opener minoxidil and the dihydrotestosterone synthesis inhibitor finasteride -- are somewhat effective for controlling male pattern baldness with long-term daily use. Regardless of which treatment is chosen for alopecia, defining and addressing the patient's expectations regarding therapy are paramount in determining outcome.