Author Affiliations: Department of Dermatology, Hospital Universitario Reina Sofía de Córdoba, Córdoba, Spain.
The Renbök phenomenon, or reverse Koebner phenomenon, was first reported in 1991 by Happle et al,1 who described 4 patients with extensive alopecia areata of the scalp with hair growth within plaques of psoriasis. Three additional cases have subsequently been reported,2- 4 and the term was later extended to include patients with mosaic phenomena, one with alopecia areata without a nevus flammeus, and another without a congenital nevus.5,6 Whereas the Koebner phenomenon involves psoriasis of traumatic or inflammatory origin, the Renbök phenomenon occurs when some inflammatory process is inhibited by psoriasis.
Garnacho-Saucedo GM, Salido-Vallejo R, Álvarez-López MÁ, Casas de la Asunción E, Ruano-Ruiz J, García-Nieto AV, Jiménez-Puya R, Moreno-Giménez JC. Renbök Phenomenon in a Patient With Alopecia Areata Universalis. Arch Dermatol. 2012;148(8):964-965. doi:10.1001/archdermatol.2012.470