Exogenous ochronosis: case report and literature review

Exogenous ochronosis is a rare, cosmetically disfiguring condition, resulting from the longterm use of topical hydroquinone in treatment of melasma. It manifests as gray-brown or blue-black macules in hydroquinone-exposed regions. The exact incidence of ochronosis is unknown. High rates have been reported in the South African population, and it is rare in the United States. We report the case of a patient who developed exogenous ochronosis while using topical hydroquinone. It is necessary to recognize this disorder at the earliest stage and discontinue hydroquinone immediately, as its treatment is difficult. Sun exposure facilitates the formation of exogenous ochronosis and must be strictly avoided, although it is a practical problem in the tropical climate of Brazil, particularly for those who work outdoors.     

Transepidermal elimination in exogenous ochronosis. A report of two cases

Exogenous ochronosis is caused by the long-term application of skin-lightening creams containing hydroquinone. This irreversible disfiguring cosmetic problem assumes epidemic proportions in South African blacks. Mild ochronosis is characterized clinically by coarsening and darkening of the skin; severe ochronosis, by coalescing, caviar-like black papules and atrophy. Histology shows ochronotic collagen fibers with eventual formation of ochronotic colloid milium. A variable cellular infiltrate, which may be granulomatous, is present. We describe two patients with severe exogenous ochronosis who developed superimposed papular lesions. Histology in both cases showed transfollicular elimination of ochronotic fibers. In one patient, gross epidermal hyperplasia, a dense lichenoid infiltrate, and partial destruction of ochronotic fibers accompanied the process of elimination (cell-rich type). In the other, concomitant epidermal hyperplasia and a cellular infiltrate were absent (cell-poor type). Further studies are needed to prove or disprove the existence of such a proposed subdivision. Transepidermal elimination in exogenous ochronosis has been mentioned in a previous report, but to our knowledge this is the first detailed documentation of this phenomenon. The clinical and histopathological spectrum of exogenous ochronosis is thus expanded.     

Endogenous ochronosis: case report and a systematic review of the literature

Background Endogenous ochronosis (EO) is a rare autosomal recessive disorder due to accumulation of oxidized and polymerized forms of homogentisic acid (HGA) in connective tissues, giving them a deep dark blue pigmentation. Aim Through a new Tunisian case of EO and a review of the literature, we aimed to define the epidemioclinical features of EO, its diagnostic criteria, and evolution. Methods Three hundred and forty patients were enrolled through 54 articles and four abstracts. Case report A 35‐year‐old woman, born in consanguineous parents, presented with blue‐grey patches of fingernails, first interdigital spaces, and ears with brown conjunctival pigmentation. Urine specimen turned dark on standing overnight. The diagnosis of EO was confirmed by urinary high levels of HGA. Investigations revealed radiologic signs of ochronotic arthropathy. Review of the literature EO is ubiquitary. Its prevalence was estimated at almost 6.5 cases/year. The mean age at diagnosis was 55.9 years (M/F: 1.85). Onset symptoms mainly consisted in cutaneous signs. Ochronotic arthropathy was the most frequently reported manifestation. Treatment was mainly symptomatic. Discussion EO is often revealed in adulthood mainly after the fourth decade. Urinary darkening is the first sign of the disease but is rarely reported as an onset sign. Skin signs are the alerting features. Ochronotic arthropathy is insidious but may be debilitating. No specific medical treatment of EO is available. Conclusion Cutaneous manifestations are the hallmarks of OE. As vital organ involvement has been reported, close monitoring and continuous surveillance is warranted.     

Endogenous ochronosis: a case description

Endogenous ochronosis or alkaptonuria is an autosomal recessive disease caused by a deficiency of the enzyme homogentisic acid oxidase. Affected individuals excrete high levels of homogentisic acid in the urine, which darkens when it is alkalinized or oxidized. Deposits of blackish-brown pigment also occur in connective tissue; this causes, usually starting around the age of 40, the typical external manifestations of this disease, along with disorders in other organs. We present a clinical case of endogenous ochronosis, a very infrequent disease in our milieu. We will discuss the most noteworthy features of the case.     

Diagnostic utility of dermatoscopy in hydroquinone‐induced exogenous ochronosis

Background Hydroquinone is the preferred topical bleaching agent used in the treatment of melasma. The adverse effects of its chronic use are confetti‐like depigmentation and exogenous ochronosis. Exogenous ochronosis manifests clinically with gray‐brown or blue‐black hyperpigmentation, as well as pinpoint hyperchromic caviar‐like papules over the malar region. Dermatoscopic findings of ochronosis are unique and point towards a clue for its diagnosis. Methods Three cases of suspected hydroquinone‐induced exogenous ochronosis while treating melasma were subjected to dermatoscopy and histopathology studies. Results Dermatoscopy in the areas of caviar‐like hyperpigmentation revealed accentuation of the normal pseudo‐rete of the facial skin with amorphous densely‐pigmented structures obliterating some follicular opening and multiple thin, short arciform structures. On histopathological examination, curved ochre‐colored structures, ‘banana‐shaped’ fibers, were seen in the dermis of all patients. Conclusion Exogenous ochronosis is difficult to treat. Dermatologists should be able to differentiate it from melasma and immediately discontinue hydroquinone. Exogenous ochronosis has characteristic features on dermatoscopy which may obviate the need for an invasive procedure of biopsy for its diagnosis.     

小汗腺汗孔瘤恶变

报告1例小汗腺汗孔瘤恶变.患者男,47岁.因左手掌皮损10年就诊.皮损表现为左手掌近小鱼际处可见直径约0.5 cm淡红色圆形肿物.组织病理检查:小汗腺汗孔瘤,增生活跃,部分区域呈非典型性.考虑患者为良性小汗腺汗孔瘤基础上恶变,并向恶性小汗腺汗孔瘤早期发展.行手术切除.     

A case of ochronosis successfully treated with the picosecond laser

Exogenous ochronosis is a cutaneous condition characterized by blue‐black pigmentation resulting as a complication of long‐term application of skin‐lightening creams containing hydroquinone and other substances such as quinine, phenol and mercury derivatives. We report a case of a 55‐year‐old woman who developed exogenous ochronosis as a result of prolonged use of topical hydroquinone for 5 years, characterized by greyish hyperpigmented patches on the nose and cheeks. The diagnosis was confirmed histologically. Treatment with picosecond laser resulted in marked clinical improvement together with improvement in overall texture and quality of the skin.     

Pyogenic granuloma-like Kaposi sarcoma: a diagnostic pitfall

Pyogenic granuloma-like Kaposi sarcoma (PG-like KS) is a clinicopathologic variant of Kaposi sarcoma (KS), a vascular tumor caused by human herpesvirus-8 (HHV-8). PG-like KS is a challenging entity to diagnose because its clinical and histological features encompass both pyogenic granuloma (PG) and KS characteristics. Immunhistochemical staining with HHV-8 latent nuclear antigen-1 (LNA-1) has been shown to exhibit high sensitivity and specificity for diagnosing KS. Therefore, the integration of clinical features and context, histopathogical findings, and immunohistochemical analysis is important in obtaining the correct diagnosis of PG-like KS. We report a case of PG-like KS in an HIV-positive man.     

司库奇尤单抗治疗伴甲损害的寻常型银屑病一例

患者,男,38岁。头皮、腋下红斑脱屑,手足甲增厚变色1年余。皮肤科查体：头皮、双侧腋下可见红斑,部分红斑上可见细小鳞屑;双手足部分甲板远端甲分离、甲下角化过度,甲变色,甲板表面可见点状凹陷。诊断为寻常型银屑病、甲银屑病。给予司库奇尤单抗治疗,皮损迅速消退,指/趾甲损害显著改善。随访1年未见皮损反复及明显不良反应。     

Exogenous ochronosis: an epidemiological study

A survey was conducted to investigate the relationship between exogenous ochronosis and the use of skin lightening preparations amongst black individuals attending general outpatient departments in two South African hospitals. In the sample, 15% of males and 42% of females were found to have exogenous ochronosis. The prevalence amongst users of skin lighteners was 69%. The main demographic associations with ochronosis were an inverse relationship to education, and predominance of the female sex. Clinical and behavioural aspects were also recorded. Even products limited to 2% hydroquinone or less, and combined with a sunscreen, were found to cause ochronosis.