Tinea Nigra is a superficial fungal infection that causes dark brown to black painless patches on the palms of the hands and the soles of the feet.

Causes

This infection is caused by the fungus formerly classified as Exophiala werneckii but more recently classified as Hortaea werneckii

Hortaea werneckii

Hortaea werneckii is a Hortaea species.It causes Tinea nigra. This skin infection causes non-scaly, smooth, brown-black painless spots on the palms of hands and soles of feet.Young cells appear brown because of melanin production in the cell wall....

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The causative organism has also been described as Phaeoannellomyces werneckii.

Diagnosis

Diagnosis of tinea nigra causing fungus is made on microscopic examination of skin scrapings, mixed with potassium hydroxide

Potassium hydroxide

Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

 (KOH). The KOH digests the nonfungal debris.

Treatment

Treatment consists of topical application of dandruff shampoo, which contains selenium sulfide, over the skin. Topical antifungal imidazoles may also be used, such as Ketoconazole. This is the same treatment plan for tinea or pityriasis versicolor.

External links

• Overview at University of Adelaide
  University of Adelaide
  The University of Adelaide is a public university located in Adelaide, South Australia. Established in 1874, it is the third oldest university in Australia...