Not all itch mediated by histamine. Central nervous system component involved in kidney and liver failure pruritis.
Treatment
- Treat dry skin
- Lidocaine 2-10% ointment/lotion used for localized itch. Toxicity possible if used over large areas
- Camphor 0.5% Menthol 0.5% in ointment base PRN
- Paroxetine 10-20mg po daily (works in 24-48 hours, sedation)
- Mirtazepine 7.5-30mg po daily (weight gain, sedation possible)
- Ondansetron 4-8mg po/sc bid (constipation)