pityriasis nigra

tin·e·a ni'g·ra

a fungus infection due to Exophiala werneckii, marked by dark lesions giving a spattered appearance and occurring most commonly on the palms of the hands.

Synonym(s): pityriasis nigra

pityriasis nigra

See tinea nigra.

pityriasis

(pit?i-ri'a-sis) [Gr. pityron, bran, scale + -iasis]

A skin disease characterized by scales that resemble bran.

pityriasis alba

A form of decreased melanin in the skin marked by patches of round or oval macular skin lesions with fine adherent scales. The lesions are commonly seen in the facial areas of children. They are virtually painless and usually require no therapy. They may disappear spontaneously. The cause is unknown, but the disease is regarded as a mild form of eczema.

pityriasis capitis

Dandruff.

pityriasis lichenoides et varioliformis, acuta

Abbreviation: PLEVA

A skin disorder characterized by development of an edematous pink papule that undergoes central vesiculation and hemorrhagic necrosis. The lesions clear spontaneously after weeks or months but leave scars.

pityriasis linguae

Transitory benign plaques of the tongue. Synonym: geographic tongue

pityriasis nigra

Tinea nigra.

pityriasis rosea

An acute inflammatory skin disease sometimes associated with human herpes virus 6 or 7 infection, marked by a macular eruption on the trunk, obliquely to the ribs, and on the upper extremities. The initial (herald) patch appears in more than half of the cases. In a few days it enlarges to several centimeters. Then, within 2 to 21 days, secondary eruptions occur. They are rose-red and somewhat scaly with a clearing in the center, or reddish ring-shaped patches symmetrically distributed over the limbs. The symptoms disappear spontaneously within 2 to 10 weeks. Treatment consists of the local application of antipruritics.

pityriasis rubra pilaris

Persistent general exfoliative dermatitis of unknown cause

See: exfoliative dermatitis

pityriasis versicolor

Tinea versicolor.