1Dermatology Department, Centro de Especialidades Medicas, Monterrey, Mexico
2University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA
3Department of Dermatology, Universidad Autonoma de Nuevo Leon, Monterrey, Mexico
4Department of Dermatology, Loma Linda University, Loma Linda, CA and University of California, San Diego, Division of Dermatology, La Jolla, CA 92161, USA