Possible allergic contact dermatitis with reticulate postinflammatory pigmentation caused by hydroquinone

A case of frog egg‐like perifollicular allergic contact dermatitis due to hydroquinone

“…However, reports of ACD from HQ are rare. To our knowledge, there are only three case reports of ACD evidenced by positive PT reactions 3–5 ; they exhibited erythematous lesions followed by exogenous ochronosis, 3 leukomelanoderma, 4 and reticulate post‐inflammatory pigmentation, 5 which are all rare expressions of ACD. Thus, HQ is considered to be a weak sensitizer, but could also be an irritant.…”

Combination treatment algorithm for pigmentary disorders of the face: A prospective observational study in Asian patients

“…The use of an incorrect dosage of hydroquinone may affect its therapeutic efficacy and contribute to adverse reactions, such as irritation. [17][18][19][20][21][22] In this study, ZO R was applied using a bottle with a pump that emits a constant volume of solution, simplifying quantification of the drug and helping avoid dosage error. At the check-up in the 1st week, the dosage already administered was checked and adjustments were made to ensure the correct dosage for the rest of the treatment course.…”

Allergic contact dermatitis caused by phenylethyl resorcinol, a skin‐lightening agent contained in a sunscreen

“…Nineteen cases of contact dermatitis caused by depigmenting agents in cosmetics have been published in 14 reports, all involving middle-aged women (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). The incriminated bleaching molecules were quite diverse.…”