ABSTRACT
This chapter describes the medical condition of itch. Itch occurs in about 10% of cancer patients. Itch and pain share the same nerve pathways, and itch is mediated via the opioid-receptor sites, which is why naloxone reduces itch. A variety of itch mediators may be responsible, including bile salts, histamine, proteases and trypsin. Local skin problems are the commonest cause of itch, and include the following: dermatitis, dry skin, infections and infestations and wet skin. Antihistamines are the usual symptomatic treatment for itching. Non-sedating antihistamines are only effective when the itch is associated with histamine wealing. Itch in renal failure probably has multiple causes. Around 70% of patients have localised itch which may respond to capsaicin cream. Being warm, dry, anxious or bored increases the awareness of itch.
