aDepartment of Pediatrics, Yale New Haven Health – Bridgeport Site, Bridgeport, Connecticut; Pediatric Healthcare Associates, Shelton, Connecticut, USA

bCentre for Rare Skin Diseases, Dermatology Department, Larrey Hospital, Paul Sabatier University, Toulouse, France

cDepartments of Dermatology and Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA

Correspondence to Amy S. Paller, MD, 676 N. St. Clair St, 16th Floor, Chicago, IL 60611, USA. Tel: +1 312 695 3721; fax: +1 312 695 0664; e-mail: [email protected]hwestern.edu