Endogenous ochronosis

Blue ears: a clue to diagnosis of alkaptonuria identified via telemedicine consultation

Alkaptonuria is a rare autosomal recessive metabolic disorder with wide systemic involvement including pigment deposition. We present an unusual case diagnosed by an image obtained via telemedicine showing pigment deposition in the earlobe. We highlight how this clue may allow prompt diagnosis of alkaptonuria and prevent disease progression.

A Mimic of Ankylosing Spondylitis, Ochronosis: Case Report and Review of the Literature

PURPOSE OF REVIEW

Ochronosis and alkaptonuria are manifestations of the same condition-a rare autosomal recessive disorder resulting from a constitutional lack of homogentisate 1,2-dioxygenase (HGD) with the consequent accumulation of homogentisic acid (HGA). In ochronosis, HGA undergoes autoxidation as well as enzymatic oxidation to form an ochronotic pigment that accumulates in cartilage and connective tissues. In the beginning, there is homogentisic aciduria and pigmentation of cartilages and other connective tissues. In later years, generalized osteoarthritis of the spine and large joints, termed ochronotic arthropathy, develops.

RECENT FINDINGS

The diagnosis is confirmed by quantitative measurement of HGA in urine and mutation analysis of the HGD gene. One of the differential diagnoses for the skin findings is exogenous ochronosis, a limited hyperpigmentation of skin caused by some chemicals. As for the lumbar spine findings, there can be radiographic similarities with ankylosing spondylitis (AS) including reduced intervertebral disc spaces and loss of lumbar lordosis; however, ochronosis will spare the sacroiliac joint, and the lumbar spine will show dense, wafer-like disk calcification with a vacuum disc phenomenon and broad syndesmophytes. Here, we present a case of a patient with probable ochronosis that was treated many years as ankylosing spondylitis without response, and we provide a review of the current literature on ochronosis pathogenesis, diagnosis, and treatment.

Eponymous signs in dermatology

Clinical signs reflect the sheer and close observatory quality of an astute physician. Many new dermatological signs both in clinical and diagnostic aspects of various dermatoses are being reported and no single book on dermatology literature gives a comprehensive list of these “signs” and postgraduate students in dermatology finds it difficult to have access to the description, as most of these resident doctor do not have access to the said journal articles. “Signs” commonly found in dermatologic literature with a brief discussion and explanation is reviewed in this paper.

Aplicação da dermatoscopia no auxílio diagnóstico da ocronose exógena

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