Prurido Crónico: Fisiopatologia, Classificação Clínica, Diagnóstico e Tratamento.

Pruritus persisting for six weeks or longer is considered chronic. It may arise from dermatological, systemic, neurological, psychosomatic or psychiatric conditions or result from a combination of several factors. Due to chronicity processes, such as peripheral and central sensitization, pruritus may persist even after treatment of the underlying cause. Additionally chronic pruritus constitutes often a high burden for the affected patients, who frequently develop associated conditions, such as anxiety, depression or sleep disorders. Owing to the multiple dimensions of chronic pruritus, it presents a diagnostic and therapeutic challenge to the attending physician. The categorization of the condition according to the clinical presentation helps directing the diagnostic and treatment efforts. Therapeutically a step-wise approach should be undertaken. First basic measures, such as the use of emollients for dry skin, topical steroids for inflamed or excoriated skin and antihistamines should be initiated. If the origin underlying the chronic pruritus is found, a causal therapy should be attempted. If no cause is found or a causal treatment is not possible, a symptomatic multimodal therapy with topical and systemic agents is often necessary. With increasing knowledge of the pathophysiological mechanisms underlying chronic pruritus, novel drugs with promising effects are being developed. [ABSTRACT FROM AUTHOR]