[1] Northwestern Univ, Feinberg Sch Med, Dept Dermatol, Chicago, IL 60611 USA
[2] Univ Groningen, Groningen, Netherlands
[3] AbbVie Inc, N Chicago, IL USA
[4] Univ Hosp Munster, Dept Dermatol, Munster, Germany
[5] Univ Hosp Munster, Ctr Chron Pruritus, Munster, Germany