Ocronose exógena induzida por hidroquinona: relato de quatro casos

Abstract

Exogenous ochronosis is an infrequent dermatosis characterized as a dark blue hyperpigmentation localized where the causing agent was applied. It may be caused by the use of systemic medication such as antimalarials and by the use of topic substances such as phenol, resorcinol, benzene, or hydroquinone, which is a fenolic compound with depigmentation action, largely used in the treatment of melasma and other hyperpigmentation. The physiopathology of this process is not well clear up to this moment, and the therapeutic measures are not satisfactory either. Here we present four cases of female patients that developed hyperpigmentation on their faces after the use of hydroquinone containing compounds, characterized clinically and histological as ochronosi. We emphasize the possibility of exogenous ochronosis cases being misdiagnosed as a melasma treatment failure. We also emphasize the risks of the indiscriminated use of hydroquinone containing compounds, used, in many instances, without medical prescription. Keywords: Hydroquinones; Hyperpigmentation; Melanosis; Ochronosis Resumo: A ocronose exógena é uma dermatose, aparentemente pouco frequente, caracterizada por hiperpigmentação negro-azulada fuliginosa, localizada na região onde foi aplicado o agente causador. Pode ser causada por uso de medicamentos sistêmicos, os antimaláricos e de uso tópico, como fenol, resorcinol, benzeno, ácido pícrico e a hidroquinona -que é um composto fenólico, com propriedade despigmentante, muito utilizado em formulações dermatológicas para o tratamento de melasma e outras hiperpigmentações. A fisiopatogenia deste processo ainda não está esclarecida e as abordagens terapêuticas são insatisfatórias. Relatam-se quatro casos de pacientes do sexo feminino que, após uso de preparados contendo hidroquinona, desenvolveram hiperpigmentação acentuada na face, caracterizadas no exame dermatológico e histopatológico como ocronose. Enfatiza-se a possibilidade de casos de ocronose exógena estarem sendo diagnosticados erroneamente, como falha de tratamento de melasma, e também para os riscos do uso indiscriminado de formulações, contendo hidroquinona, muitas vezes, sem acompanhamento médico.

Aplicação da dermatoscopia no auxílio diagnóstico da ocronose exógena

“…Some reports describe cases of EO with use of concentrations of hydroquinone 2%, suggesting that in some patients the concentration of the substance is not the most important risk factor. 10,11 The high prevalence of pigmentary disorders in patients with high phtotype in Fitzpatrick scale would be one of the factors for a greater number of described cases in this population. However, there are reports in patients who are Asian and Caucasian descendants.…”

“…These findings were similar to the ones found by Berman et al 13 Many therapeutic options are described for the treatment of EO such as retinoic acid, glycolic acid, azelaic acid, Q-switched (755nm) laser, but all them with unsatisfactory results. 10,14 As most EO cases are iatrogenic resulting from inadequate use of hydroquinone for the treatment of melasma, dermatologists should pay attention not only to prevention but also to early diagnosis of EO. As there are few reports about the use of dermoscopy to help to diagnose EO the authors present three cases where dermoscopy was efficient in the differentiation between pre-existing melasma and exogenous ochronosis.…”

Toxics in cosmetics: chemical properties, impact mechanism and clinical cases derived from major chemical components

“…Experiments results showed that the inhibition of the enzyme that oxidized by hydroquinone, leading to the accumulation of homogentisic acid which transforms into ochronotic pigment. [10] In Riba's paper in 2010, there were 4 specific clinical reports which shows how hydroquinone affects skins. In case 01, a 36-year-old female patient who was treated with 2% concentration of hydroquinone for 5 years got facial melanoma appeared in molar region, and symmetrically on dorsal of the supralabial and nose (for 8 years??).…”

“…Reported cases of skin damage caused by using hydroquinone containing cosmetics Experiments were conducted to further discover the relationship between hydroquinone and exogenous ochronosis. Experiments results showed that the inhibition of the enzyme that oxidized by hydroquinone, leading to the accumulation of homogentisic acid which transforms into ochronotic pigment [10]. In Riba's paper in 2010, there were 4 specific clinical reports which shows how hydroquinone affects skins.…”

Evidence-Based Treatment for Melasma: Expert Opinion and a Review

“…Moin et al [ 3 ] found a statistically significant relationship between melasma and ethnicity, and phototype and grade of parity. Exogenous ochronosis has also been reported to be being misdiagnosed as a melisma treatment failure [ 76 ]. However, these prognostic factors lack sufficient scientific evidence.…”