[1] Univ Toronto, Div Dermatol, Dept Med, Toronto, ON, Canada
[2] Univ Toronto, Temerty Fac Med, Toronto, ON, Canada
[3] Univ Toronto, Mt Sinai Hosp, Div Gastroenterol, Dept Med, Toronto, ON, Canada
[4] Womens Coll Hosp, Div Dermatol, Dept Med, Toronto, ON, Canada
[5] Hosp Sick Children, Dermatol Sect, Dept Pediat, Toronto, ON, Canada