Exogenous Ochronosis (EO): Skin lightening cream causing rare caviar-like lesion with banana-like pigments; review of literature and histological comparison with endogenous counterpart

Ochronosis is a cutaneous disorder caused by the accumulation of phenols, either endogenously as homogentisic acid in patients with alkaptonuria (autosomal recessive disorder with deficiency of the enzyme homogentisic acid oxidase), or exogenously in patients using phenol products such as topical creams containing hydroquinone or the intramuscular application of antimalarial drugs. Exogenous ochronosis (EO) typically affects the face and was reported in patients with dark skin such as Black South Africans or Hispanics who use skin-lightening products containing hydroquinone for extended periods. Recently more cases have been reported worldwide even in patients with lighter skin tones, to include Eastern Indians, Asians, and Europeans. However, just 39 cases of EO have been reported in the US literature from 1983 to 2020. Here we present two cases; a 69 and a 45-year-old female who were seen for melasma, given hydroquinone 4% cream daily and tretinoin 0.05%. Both patients noticed brown spots on their cheeks, which progressively enlarged and darkened in color. The diagnosis of ochronosis was confirmed by characteristic histopathological features on the punch biopsy. Unfortunately, neither patient responded to multiple treatments (to include, tazarotene 0.1% gel and pimecrolimus ointment, topical corticosteroids, and avoidance of hydroquinone containing products). We also present a case of classic (endogenous) ochronosis in a patient with alkaptonuria to picture the histological similarities of these two entities. EO is an important clinical consideration because early diagnosis and treatment may offer the best outcome for this notoriously refractory clinical diagnosis.

Alcaptonúria (ocronose): relato de caso de irmãos / Alkaptonuria (ochronosis): a case report of siblings

A Alcaptonúria é uma doença autossômica recessiva rara caracterizada pelo acúmulo de ácido homogentísico. Denomina-se também ocronose e manifesta-se por pigmentação azulada de tecidos orgânicos e urina enegrecida, além de artropatia. A seguir, será relatado o caso de irmãos portadores de artropatia ocronótica e a conduta ortopédica (AU)

Alkaptonuria is a rare autosomal recessive disease characterized by the accumulation of homogentisic acid. It is also called ochronosis and is manifested by bluish pigmentation of organic tissues and blackened urine, besides arthropathy. Here the authors report the case of siblings with ochronotic arthropathy and the orthopedic management (AU)

Aplicação da dermatoscopia no auxílio diagnóstico da ocronose exógena / Use of dermoscopy for diagnosis of exogenous ochronosis

A ocronose exógena consiste em hiperpigmentação crônica de áreas previamente tratadas com agentes tópicos como: a hidroquinona, a resorcina, os antimaláricos e o fenol. O diagnóstico precoce permite suspender prontamente o agente causador, uma vez que as opções terapêuticas disponíveis são escassas e com resultados insatisfatórios. Reportam-se três casos de ocronose exógena na face, diagnosticados pela dermatoscopia. O estudo dermatoscópico evidenciou estruturas amorfas de coloração cinza-enegrecido, algumas obliterando as aberturas foliculares. O exame histopatológico corroborou o diagnóstico.

Exogenous ochronosis consists of chronic hyperpigmentation of areas previously treated with topical agents such as hydroquinone, resorcinol, antimalarials and phenol. Early diagnosis allows to promptly suspend the causative agent and it is imperative since the available therapeutic options are scarce and have presented so far unsatisfactory results. Three cases of exogenous ochronosis on the face which were diagnosed with the use of dermoscopy are presented. Dermatoscopy showed blackish-gray amorphous structures, some obliterating the follicular openings. Histopathological examination confirmed the diagnosis.

Ocronose exógena induzida por hidroquinona: relato de quatro casos / Exogenous ochronosis hydroquinone induced: a report of four cases

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.

Gonartrosis por ocronosis alkaptonurica: reporte de un caso y revisión de la literatura / Gonarthrosys by ochronosis alkaptonuria: a case report and literature review

La ocronosis alkaptonurica es una rara enfermedad autosómica recesiva del metabolismo de la tirosina y fenilalanina caracterizada por una triada de orinas oscura (alkaptonuria), coloración negruzca de tejidos conectivos (ocronosis) y degeneración articular en adultos jóvenes (artritis ocronotica), por deficiencia del la 1,2 dioxigenasa homogentísica, produciendo la acumulación del Ácido Homogentísico (HGA). De tratamiento poco efectivo tanto con Vitamina C como con Nitisinone, aunque este último inhibe síntesis HGA. Se hace el reporte de una paciente femenina de 53 años, con gonartrosis bilateral severa a predominio izquierdo, sin antecedentes patológicos conocidos, que durante la artroplastia se evidenciaron lesiones negruzcas en todo el cartílago articular, por lo que se tomaron muestras para anatomía patológica que reportaron lesiones sugestivas de artrítis ocronótica. Posteriomente se evidencia orinas oscuras a la exposición al aire libre, artropatía degenerativa no limitante en esqueleto axil y parentesco de consanguinidad tanto de sus abuelos como de sus padres. Se hace este reporte por ser el primer caso registrado en la literatura nacional, además de su excepcional frecuencia.

Artropatia ocronótica / Ochronotic arthropathy

Os autores apresentam o relato de caso de um paciente com artropatia ocronótica. A ocronose é uma doença rara, de herança autossômica recessiva, manifestação clínica da alcaptonúria. O paciente apresenta clinicamente dor crônica lombar, fraqueza e limitação funcional dos ombros e joelhos, associada a urina de cor escura. O objetivo do tratamento ortopédico é o controle da dor e melhora das funções das articulações acometidas, realizando artroplastias quando necessário.

Hip arthroplasty for ochronosis

Alkaptonuria is a metabolic disorder in which homogentisic acid oxidase is absent. Therefore, homogentisic acid accumulates in cartilage and connective tissues. We can diagnose ochronotic arthropathy, a manifestation of long standing alkaptonuria, through careful radiological, physical, and laboratory examination. In this report, we describe 4 cases of ochronotic arthropathy to which we applied cementless total hip prosthesis due to severe hip involvement