title: Pigmented contact dermatitis due to therapeutic sensitizer as complication of contact immunotherapy in alopecia areata.
abstract: Pigmentary complication by contact immunotherapy (CI) for alopecia areata (AA) has been reported but its pathophysiology remains unknown. To characterize pigmentary complication by CI and its pathophysiology, we examined the incidence of hyperpigmentation in 186 consecutive patients treated with CI using diphenylcyclopropenone. From clinical data of AA totalis (AAT) or universalis (AAU) patients (n = 78), we studied the correlations between this complication and age, sex, atopic background, duration and treatment responsiveness, duration of CI, final concentration of diphenylcyclopropenone and administration of anti-histamines by χ(2)-test or Mann-Whitney U-test. Additionally, the histopathology of pigmentation was studied. As a result, 11 (5.91%) of the 186 patients had hyperpigmentation in this series. All of them had AAT or AAU, suggesting that the pigmentation is apt to occur in severe AA. When the AAT or AAU patients with (n = 11) and without hyperpigmentation (n = 67) were compared, those with pigmentation showed poorer responsiveness to CI (P < 0.05) but no significant tendency for other factors. Histopathologically, skin specimens showed lichenoid or vacuolar interface dermatitis with necrotic keratinocytes and dermal melanophages, consistent with pigmented contact dermatitis (PCD). Together, pigmentary complication by CI corresponds to PCD from therapeutic sensitizer, representing clinical indicator of poor responsiveness.
authors.affiliation: Department of Regenerative Dermatology, Osaka University School of Medicine, Suita, Osaka, Japan. inui@r-derma.med.osaka-u.ac.jp
authors.forename: Shigeki
authors.initials: S
authors.lastname: Inui
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Toda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Itami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000506:Alopecia Areata / Q000628:therapy*; D002648:Child; D003521:Cyclopropanes / Q000009:adverse effects*; D003877:Dermatitis, Contact / Q000209:etiology*; D003879:Dermatologic Agents / Q000009:adverse effects*; D005260:Female; D006801:Humans; D017495:Hyperpigmentation / Q000139:chemically induced* / Q000473:pathology; D007167:Immunotherapy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003521:Cyclopropanes; D003879:Dermatologic Agents; C029402:diphenylcyclopropenone