Pityriasis Versicolor

(also called tinea versicolor), a fungal disease of the skin that proceeds without affecting the hair or nails. Pityriasis versicolor is classified as a dermatomycosis. The causative agent is the pathogenic mycelial fungus Microspo-ron furfur. The disease is localized predominantly on the skin of the chest, back, neck, and shoulders. It is characterized by the appearance of sharply delineated, gradually enlarging, irregularly shaped desquamatory scales that are yellow-pink, light brown, or dark brown in color. As a rule, no internal sensations arise. Without proper treatment, the disease, which is only slightly infectious, may persist for decades. Depigmented spots mark the sites of previous rashes, especially after exposure to ultraviolet radiation. Pityriasis versicolor is treated with desquamatory agents and can be prevented with conscientious care of the skin and control of perspiration.

pityriasis versicolor

pityriasis

[pit″ĭ-ri´ah-sis] any of various skin diseases characterized by the formation of fine, branny scales.acute lichenoid pityriasis an acute or subacute, sometimes relapsing, widespread macular, papular, or vesicular eruption that tends to crusting, necrosis, and hemorrhage; when it heals it leaves pigmented depressed scars, followed by a new crop of lesions. Progression to the chronic lichenoid form occasionally occurs.pityriasis al´ba a chronic condition with patchy scaling and hypopigmentation of the skin of the face.chronic lichenoid pityriasis a chronic brown to red-brown scaly macular eruption, seen mainly on the trunk, with epidermal changes and a perivascular lymphocytic infiltrate. It may arise independently or happen as a progression of the acute lichenoid form.pityriasis ro´sea a common acute or subacute, self-limited exanthematous disease of unknown etiology. It begins with a solitary red to tan plaque (herald plaque), usually on the trunk, arms, or thighs, which is followed by similar but smaller papular or macular lesions; these later may peel and leave a scaly collarette.pityriasis ru´bra pila´ris a chronic inflammatory skin disease marked by pink scaling macules and cone-shaped horny follicular papules; it usually begins with severe seborrhea of the scalp and face, associated with keratoderma of palms and soles.pityriasis versi´color tinea versicolor.

tin·e·a ver·sic·'o·lor

an eruption of tan or brown branny patches on the skin of the trunk, often appearing white, in contrast with hyperpigmented skin after exposure to the summer sun; caused by growth of the fungus Malassezia furfur in the stratum corneum with minimal inflammatory reaction. Synonym(s): pityriasis versicolor

tin·e·a ver·si·col·or

(tin'ē-ă vĕr'si-kŏ-lŏr) An eruption of tan or brown branny patches on the skin of the trunk, often appearing white, in contrast with hyperpigmented skin after exposure to the summer sun; caused by growth of Malassezia furfur in the stratum corneum with minimal inflammatory reaction.
Synonym(s): pityriasis versicolor.

pityriasis versicolor

A common fungus infection of the outer layer of the skin (the EPIDERMIS) that causes white, brown, or salmon-coloured flaking patches. The condition may be inapparent until the unaffected skin becomes tanned by the sun. Treatment is by antifungal creams or lotions.