PITYRIASIS

(Lat.), n. f. PiH-iMu(!r)-i;!-as(a3s)'i:!s. Gen., -as'eos ia's is). Gr., TriTvpcatris (from nirvpov, bran). Fr., herpes furfueux volatil, dartre furfur a cee (ou farineuse), teigne furfur a cee. Ger., Kleienau chlag, Kleiengrind. Exfoliation of the skin in the:orm of branny scales; formerly (and by some still) regarded as an ndependent disease, but now by most dermatologists considered only as a secondary condition incident to various cutaneous diseases. [G.] Hebra's p. Chronic p. rubra. [" Un. med. et sci. du Nord-Est."; "Province med.," Oct. 6, 1888, p. 577.] " P. acneique. Of Bazin, p. characterized by the appearance "of a series of true acne-pustules, situated at the base of the hairs at the circumference of scaling patches. [G.] P. alba of the external ear. A rare mycosis of the external auditory canal sometimes atfuracee, cra e de la tete. Ger., Kopfschabe. P. of the scalp or tiead; dandruff. [G.] Cf. SEBORRHCEA. P. chronique et circonscrit (Fr.). Of Bazin, a chronic circumscribed form of p., e entially identical in character with seborrhrea sicca. [G.] P. circinata. Of Horand, see P. rose a.V. circinata et margin at a. A parasitic disease of the skin characterized by rose-colored or pale-brown patches on the trunk and extremities and in the axillee. [Vidal, " Proc. of the Internal. Med. Cong.," 1881, iii, p. 167 (G).] P. e ential is. Idiopathic p., p. rubra. [G.] P. gravida ruin. See CHLOASMA gravid arum.V. indica. See P. nigra.- P. in fan til is. P. of infants; according to Fuchs, an eruption affecting infants, attended not only with desquamation but also with vesicles, erosions, and moist exudation; probably eczema. [G, 5.] P. in namma to ire (Fr.). Of Bazin, a chronic circumscribed form of p. occupying hairy parts of the body, and attended with a copious reduction of large adherent scales on a reddened surface. [G.]. Jf. SEBORRHCEA congestiva.P. maculata et circinata. Fr.,p. rubra aigu, p. macule et circine. Of Baziu, a form of p. described as " pseudo-exanth6matique arthritique," characterized by red or rose-colored spots that coalesce to form either large patches or ings, and attended with furfuraceous desquamation. [G.] Cf. P. ose a and ROSEOLA furfur ace a her pet i form is. P. nigra. Fr., ephelide scorbutique. 1. See MELASMA. 2. Of Will an, a cutaneous affection observed in children born in India and afterward brought to England. It "commenced in a partial papulation of the skin, and terminated in a black discoloration with slight furfuraceous exfoliations." According to Rayer. p. is frequently a ociated with pellagra. 3. Of Bazin. a parasitic affection, p. versicolor of a darker color than usual. [G, 10, 15.] P. rose a. 1. An acute inflammatory disease of the skin characterized by an eruption of pale-red or rose-colored scaly patches and rings. A macular form (p. maculata) and a circinate form (p. circinata) have been described. The macular form, which is the one first described by Gibert, occurs in rose-colored papules or in small reddish patches slightly scaling and but little elevated above the surrounding skin, appearing most commonly upon the neck or trunk and thence spreading. The circinate form represents a later stage of the disease, in which the patches, extending at the periphery, leave a smooth fawn-colored centre, with red and scaling borders. [" N. Y. Med. Jour.," Dec. 24, 1887, p. 724, and Mar. 8, 1890, p. 278 (a, 17); G, 25.] 2. Cf. HERPES tonsurans maculosus, P. maculata et circinata, and P. circinata et margin at a.F. rubra. Ger., Rothkleie, rot he Kleienflechte. 1. A disease characterized by intense hyperEemia of the skin attended by very copious exfoliation of the epidermis. The affection may continue for years, producing atrophy and contractions of the skin and general marasmus. Many authors make a distinction between the p. rubra of Hebra, that arises independently of any antecedent cutaneous affections, such as psoriasis, and tends to a very protracted course with atrophy of the skin, and other le severe forms of disease that have been described under the name of exfoliativa dermatitis. 2. Of Bazin, p. in flamm a to ire. 3. A hyperaemic condition of the skin which sometimes follows eczema. [G.] 4. See P maculata et circinata. Y. rubra pilar is. See LICHEN ruber. P. senilis. P. of the aged. Of the older writers (as generally used), eczema. [G.] P. simplex. Fr., p. simple. P. not attended with hyper semi a or redne . The term is used to distinguish the simpler forms of p. (such as p. capitis, etc.) from p. rubra and p. versicolor. [G.] P. tabescentium. Seborrhoea. |G.] P. versicolor. Ger., Kleienflechle. 1. An old name for certain forms of chroma to sis. 2. More recently, derma to mycosis furfur ace a. P. vulgar is. See P. simplex. [s. 279]