Squaric acid sensitization is not required for response in the treatment of alopecia areata.
BACKGROUND
Topical immunotherapy using potent contact allergens, such as squaric acid dibutylester (SADBE), can be used to treat alopecia areata. However, there are conflicting reports regarding the best protocol for its administration, particularly with regard to the necessity of an eczematous response after the initial sensitization treatment.


OBJECTIVE
We sought to assess the impact of initial sensitization on subsequent hair regrowth.


METHODS
This is a retrospective review of the use of SADBE in the treatment of alopecia areata in 14 patients.


RESULTS
Eleven of 14 patients underwent initial sensitization before initiating treatment. Three of these patients had an eczematous reaction after 1 attempt, 5 after ≥2 attempts, and 3 failed to develop a clinical reaction. Four of 14 initiated treatment without a clinical reaction or a previous sensitization. Eleven of 14 patients experienced regrowth, 7 with previous sensitization and 4 without.


CONCLUSIONS
This observational study is limited by sample size.


CONCLUSIONS
SADBE sensitization regimens and reactions vary widely, and the absence of an initial eczematous reaction to sensitization does not predict a failed response with continued SADBE treatment.
Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts.
Priyanka
P
Vedak
Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts. Electronic address: dkroshinsky@partners.org.
Daniela
D
Kroshinsky
D000287:Administration, Topical; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000506:Alopecia Areata / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003503:Cyclobutanes / Q000494:pharmacology*; D005260:Female; D005500:Follow-Up Studies; D006197:Hair / Q000187:drug effects / Q000254:growth & development*; D006801:Humans; D007114:Immunization; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment; D012494:Sampling Studies; D016896:Treatment Outcome; D055815:Young Adult
D000305:Adrenal Cortex Hormones; D003503:Cyclobutanes; C020637:squaric acid dibutyl ester; C030042:squaric acid
alopecia areata; squaric acid dibutylester; topical immunotherapy