pityriasis rubra pilaris


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.

pit·y·ri·a·sis ru·'bra pi·la·'ris

[MIM*173200] an uncommon chronic pruritic eruption of the hair follicles, which become firm, red, surmounted with a horny plug, and often confluent to form scaly plaques; it is most conspicuously noted on the dorsa of the fingers and on the elbows and knees and is associated with erythema, thickening of the palms and soles, and opaque thickening of the nails.

pi·tyr·i·a·sis ru·bra pi·la·ris

(pit'i-rī'ă-sis rū'bră pī-lā'ris) An uncommon chronic pruritic eruption of the hair follicles, which become firm, red, surmounted with a horny plug, and often confluent to form scaly plaques.