Itch in atopic dermatitis - pathophysiology and treatment.

Pruritus is an essential feature of atopic dermatitis with a high impact on the quality of life. Although the pathophysiology of atopic dermatitis itch is not fully understood, recent studies have demonstrated that a variety of mechanisms contribute to the induction and maintenance of the symptom. For example, an increased number of cutaneous nerve fibers and neuropeptides were identified in atopic dermatitis skin. Histamine and histamine 4 receptor as well as interleukin 31 are novel key players identified in itch induction, in addition to inflammatory cells such as mast cells, eosinophils and lymphocytes. The new findings suggest that target-specific therapies are most likely to control atopic dermatitis itch. To date, only few therapies are available and controlled studies are pending.