A skin disease marked by the appearance of localized and circumscribed patches of thickened skin with lichenification, becoming scaly, without inflammatory changes, on the buttocks, thighs, abdomen, back, and arms, resulting from repetitive rubbing and scratching subsequent to pruritogenic stimuli. Common in Far East populations, less in South Africas, Bantus, Egyptians, and West Indias; onset between 7 and 76 years of age. Pregnancy or infection may precipitate onset.
Toyama's syndrome, or pityriasis circinata, is entered as a separate entity under T. Toyama, Japanese physician.
- E. Vidal:
Du lichen (lichen, prurigo, strophulus).
Annales de dermatologie et de syphilographie, Paris, 1886, 2 sér, 7: 133-154.
- C. Aguilera Maruri, L. Aguileri Diaz:
Le pityriasis circiné et marginé de Vidal, Maladie autonome.
Annales de dermatologie et de syphilographie, Paris, 1968, 95: 49-57.