1/5. Hereditary ochronosis: hyperpigmented skin overlying cartilaginous structures.Hereditary ochronosis, or alkaptonuria, results from deficiency of homogentisic acid oxidase. It is an autosomal recessive condition found in geographically isolated populations. The excess homogentisic acid deposits in collagenous structures, leading to unusual pigmentation of the skin overlying cartilaginous structures, but on occasion pigment is also seen in the sclera, in sweat after oxidation, and classically, in urine when left standing at room temperature. This case report highlights the pathogenesis and expression of this rare disorder.- - - - - - - - - - ranking = 1keywords = ochronosis (Clic here for more details about this article) |
2/5. Vaginal hyperpigmentation due to ochronosis.BACKGROUND: ochronosis is a manifestation of alkaptonuria, a rare metabolic disorder. It results in the accumulation of pigment in connective tissues. After several years, ochronosis may produce a distinctive form of degenerative arthritis.CASE: Vaginal ochronosis was diagnosed in an asymptomatic elderly woman with vaginal hyperpigmentation and severe degenerative arthritis.CONCLUSION: Vaginal hyperpigmentation is a rare clinical finding that necessitates biopsy.- - - - - - - - - - ranking = 1.2keywords = ochronosis (Clic here for more details about this article) |
3/5. minocycline-induced hyperpigmentation masquerading as alkaptonuria in individuals with joint pain.alkaptonuria, a rare autosomal-recessive disorder caused by mutations in the HGD gene and a deficiency of homogentisate 1,2-dioxygenase, is characterized by accumulation of homogentisic acid (HGA), ochronosis, and destruction of connective tissue resulting in joint disease. Certain medications have been reported to cause cutaneous hyperpigmentation resembling that of alkaptonuria. We present 5 such cases. Eighty-eight patients with a possible diagnosis of alkaptonuria were examined at the National Institutes of health Clinical Center between June 2000 and March 2004. The diagnosis of alkaptonuria was confirmed or ruled out by measurement of HGA in the urine. Five patients with findings consistent with ochronosis, including pigmentary changes of the ear and mild degenerative disease of the spine and large joints, were diagnosed clinically as having alkaptonuria, but the diagnosis was withdrawn based on normal urine HGA levels. All 5 patients were women who had taken minocycline for dermatologic or rheumatologic disorders for extended periods. minocycline-induced hyperpigmentation should be considered in the differential diagnosis of ochronosis. This could be of increased significance now that minocycline and other tetracyclines have been proposed as therapeutic options for rheumatoid arthritis, bringing a new population of patients with ochronosis and arthritis to medical attention with the potential, but incorrect, diagnosis of alkaptonuria.- - - - - - - - - - ranking = 0.8keywords = ochronosis (Clic here for more details about this article) |
4/5. Exogenous ochronosis and striae atrophicae following the use of bleaching creams.Exogenous ochronosis is a paradoxical hyper-pigmentation of the skin caused by the long-term use of hydroquinone-containing bleaching creams. ochronosis is an uncommon condition characterized by yellow-brown pigmented deposits in the dermis. We report two cases of exogenous ochronosis in two female patients of the sub-Saharan African population. The lesions were characterized by an asymptomatic hyper-pigmentation of the face with gradually progressive blue-black macular patches, and in case no. 2, in addition to dyschromic lesions, striae atrophicae were present. This phenomenon is the outcome of the use of skin care products containing high concentrations of hydroquinone- and glucocorticoid-based products, and, in addition, certain modalities in the use of bleaching products are likely to facilitate complications.- - - - - - - - - - ranking = 1.2keywords = ochronosis (Clic here for more details about this article) |
5/5. Alkaptonuric ochronosis: report of two affected brothers.Alkaptonuric ochronosis is a rare inborn metabolic disorder. Because of the deficient activity of the enzyme homogentisic acid oxidase, homogentisic acid accumulates in plasma, is deposited in various tissues and is excreted in large amounts in urine. Dark brown discoloration of urine on exposure to air or after addition of alkaline solution is characteristic. We describe two brothers with typical alkaptonuric ochronosis with dark urine, blue pigmentation of auricles and axillae, focal brown hyperpigmentation of sclerae, and anthropathy.- - - - - - - - - - ranking = 1.2keywords = ochronosis (Clic here for more details about this article) |