Topical immunotherapy in alopecia areata

Abstract

Alopecia Areata (AA) is a common non-scarring alopecia directed against the anagenic hair follicle. Various treatment modalities have been used for the treatment of severe AA. Topical immunotherapy is the best documented treatment so far for severe and refractory AA. Dinitrochlorobenzene (DNCB), squaric acid dibutylester (SADBE), and diphencyprone (DPCP) are the contact allergens used for this purpose. DNCB has been found to be mutagenic by the Ames test and is largely replaced by DPCP and SADBE. DPCP and SADBE are both known to be non-mutagenic compounds and have comparable efficacy results and relapse rates. SADBE requires special solvents and additives to maintain its potency and is more expensive than the rest. DPCP has a response rate varying from 60% in severe Alopecia Areata to 17% in patients with alopecia totalis or universalis, and shows about 88 to 100% high response rate in patients with patchy Alopecia Areata.

Alopecia areata: An update

“…The efficacy of the both agents is almost same 50-60% with a range of 9-87%. [70,71] DPCP is preferred over SADBE as it is cheap and more stable in acetone, which is a potent UV-absorber. DPCP is light-and heat-sensitive, and it should be stored in amber-colored bottles.…”

“…[68] ANTHRALIN ANTHRALIN Anthralin is an irritant, and it's mechanism of action in AA is unknown. It is effective because of its Corticosteroids [5,29,[63][64][65] Corticosteroids [63][64][65][78][79][80][81][82][83][84][85][86][87] Cyclosporine A [91] Calcineurin inhibitors [97,98] Minoxidil [66][67][68] Sulfasalazine [88,89] Methotrexate [92] Biologicals [99,100] Anthralin [5,65] PUVA [90] Azathioprine [93] NBUVB [101] Immunotherapy [69][70][71][72] Capsaicin [94] Phototherapy [73,74] Topical bexarotene 1% gel [95] Prostaglandin analogues [75][76][77] Camoufl age [96] immunosuppressive and anti-inflammatory properties by generating free radicals. [5] It...…”

From pathways to people: applying the adverse outcome pathway (AOP) for skin sensitization to risk assessment

“…Demonstrated in vitro predictive power would provide more confidence when changing to an in vivo parameterization and predicting the response to an actual exposure scenario in humans. Ideally, model predictions and observations should be made in the system of interest and, to this end, topical immunotherapy may provide an opportunity to ethically study the emergence of a sensitizer-specific T cell response in humans (Singh and lavanya, 2010). the purpose of such an evaluation would be to provide sufficient confidence in the underlying mechanistic assumptions modeled in order to make predictions on novel ingredients for which no clinical data is available.…”

Limited Effectiveness of Platelet-Rich-Plasma Treatment on Chronic Severe Alopecia Areata

“…Topical immunotherapy: Topical immunotherapy may be useful for severe and refractory cases of AA especially in children whom treatment options are more limited [20]. It is hypothesized that the allergic reaction created by the topical immunotherapy generates suppressor T cells that inhibits an autoimmune reaction against the hair follicle [20].…”

“…It is hypothesized that the allergic reaction created by the topical immunotherapy generates suppressor T cells that inhibits an autoimmune reaction against the hair follicle [20]. Initially patients are sensitized by applying 2% DPCP in acetone or paraffin to the inner arm or a small area on the scalp under waterproof occlusion for 48 hours.…”