[Pruritus in systemic diseases : Common and rare etiologies]

Area of Science:

• Internal Medicine
• Dermatology
• Pharmacology

Background:

• Chronic pruritus can be a symptom of internal disorders, distinct from primary skin conditions.
• Intense scratching can lead to secondary skin changes like abrasions and excoriations.
• Common internal causes include chronic kidney disease, hepatobiliary and hematological disorders, and adverse drug reactions.

Purpose of the Study:

• To review the internal medicine causes of chronic pruritus.
• To discuss the current understanding of pruritus pathogenesis in internal disorders.
• To outline antipruritic treatment strategies for various internal medicine-related conditions.

Main Methods:

• Literature review of internal medicine causes of chronic pruritus.
• Summary of current knowledge on pruritus pathogenesis.
• Overview of established and potential antipruritic treatments.

Main Results:

• Chronic kidney disease, hepatobiliary, and hematological disorders are common causes of non-dermatological pruritus.
• Gabapentin and pregabalin are effective for chronic kidney disease-associated pruritus; nalfurafine is approved in Japan.
• Cholestyramine and rifampicin are effective for hepatobiliary pruritus; μ-opioid receptor antagonists and sertraline may help cholestatic pruritus.

Conclusions:

• Antipruritic treatment for internal disorders is often symptomatic and challenging.
• Targeting the underlying disease is the primary therapeutic approach.
• Further research, including randomized controlled trials, is needed for non-uremic and non-cholestatic pruritus.