Prurigo nodularis – an update on an important disease

Prurigo nodularis (PN) is defined as a clinical pattern of mostly symmetrically papules and nodules and belongs to the group of chronic pruritic diseases. Underlying diseases can be skin diseases (e.g. atopic dermatitis or lichen planus), internal medical diseases (e.g. hepatic or renal diseases), and neurological or psychiatric diseases. Recently, new insights into the pathogenesis of PN have revealed an important role of various neuropeptides such as substance P in the maintenance of the itch–scratch cycle of PN. As a consequence, new clinical trials are being conducted to verify a potential benefit by blocking these substances. However, till today, standard therapy regimens for PN include, apart from the treatment of underlying diseases, topical steroids, antihistamines, phototherapy, anticonvulsants, antidepressants, opioid receptor antagonists, and, finally, immunosuppressants.