pityriasis rubra pilaris

pityriasis /pit·y·ri·a·sis/ (pit″ĭ-ri´ah-sis) any of various skin diseases characterized by the formation of fine, branny scales.

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pityriasis al´ba  a chronic condition with patchy scaling and hypopigmentation of the skin of the face.

pityriasis ro´sea  a dermatosis marked by scaling, pink, oval macules arranged with the long axes parallel to the cleavage lines of the skin.

pityriasis ru´bra pila´ris  a chronic inflammatory skin disease marked by pink scaling macules and horny follicular papules, beginning usually with seborrhea of the scalp and face, with keratoderma of palms and soles.

pityriasis versi´color  tinea versicolor.

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pityriasis rubra pi·lar·is (p-lârs)

n.

A chronic eruption of the hair follicles, which become firm, red, surmounted with horny plugs, and often form scaly patches.

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pityriasis rubra pilaris

Etymology: Gk, pityron, bran; L, ruber red, pilus, hair

a chronic inflammatory cutaneous disease characterized by tiny acuminate, reddish brown follicular papules topped by central horny plugs in which are embedded hairs; disseminated yellowish pink scaling patches; and often solid confluent hyperkeratosis of the palms and soles with a tendency to fissuring.

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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.