References

Ständer S, Weisshaar E, Mettang T, Szepietowski JC, Carstens E, Ikoma A, Bergasa NV, Gieler U, Misery L, Wallengren J, Darsow U, Streit M, Metze D, Luger TA, Greaves MW, Schmelz M, Yosipovitch G, Bernhard JD.
Clinical classification of itch: a position paper of the International Forum for the Study of Itch.
Acta Derm Venereol 2007; 87(4): 291-294

Weisshaar E, Szepietowski JC, Darsow U, Misery L, Wallengren J, Mettang T, Gieler U, Lotti T, Lambert J, Maisel P, Streit M, Greaves MW, Carmichael AJ, Tschachler E, Ring J, Ständer S.
European guideline on chronic pruritus.
Acta Derm Venereol 2012; 92(5): 563-81