Abstract Ramsay Hunt Syndrome (RHS), also known as herpes zoster oticus, is caused by the reactivation of varicella zoster virus (VZV) in the geniculate ganglion of the facial nerve. Herein, we report a case of Ramsey Hunt Syndrome in a patient after antimonial treatment for Cutaneous Leishmaniasis. The patient presented with microvesicles grouped on an erythematous base, starting in the neck and ascending towards the scalp margin on the right side of the head. The patient also developed grade V peripheral facial palsy the day after initiating the herpes zoster treatment, this outcome corroborated the assumption of Ramsey Hunt Syndrome.

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.

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.