Pruritus

Pruritus (itch) is an unpleasant sensation of the skin or mucous membranes that provokes the desire to scratch or rub. It can be distressing if persistent or widespread.
Pruritus can be categorised as:

• Prurioceptive – Chemically induced itch via the C-fibres (e.g. Histamine).
• Neuropathic – Damage to the afferent pathway (e.g. post herpetic pruritus).
• Neurogenic – Centrally acting pathway (e.g. uraemic pruritus).
• Psychogenic – Associated with anxiety and psychological disorders.

General Skin Care

• Removal of causative agents
• Emulsifying ointment/oatmeal emollients/aqueous cream
• Avoid hot baths
• Dry skin by patting, not rubbing
• Emollient post shower
• Avoid overheating, sweating and dehydration
• Discourage scratching, allow gentle rubbing and wear cotton gloves if severe itch

Disease Specific

• End Stage Renal failure
  
  • Antihistamine at night for sedation (to reduce scratching)
  • Gabapentin 100mg at bedtime and titrate as needed
  • Doxepin 10-30mg at bedtime
  • Paroxetine 10-40mg at bedtime
  • Phototherapy
• Cholestasis
  
  • Cholestyramine 4g t.d.s.
  • Mirtazapine 7.5-45mg at bedtime
  • Paroxetine 10-40mg at bedtime
  • Rifampicin 300-600mg/day
  • Naltrexone (opioid antagonist) 50-100mg once daily if not on systemic opioids
• Hematological Causes
  
  • Iron replacement
  • Paroxetine 10-40mg at bedtime
  • Fluvoxamine 50mg at bedtime
  • Mirtazapine 7.5-45 mg at bedtime
  • Aspirin (for polycythemia rubra vera)
  • Phototherapy
• Opioid Induced
  • Switch opioids
  • Ondansetron 4-8mg t.d.s.

• Xander C, Meerpohl JJ, Galandi D, Buroh S, Schwarzer G, Antes G, et al. Pharmacological interventions for pruritus in adult palliative care patients. Cochrane Database Syst Rev. 2013;(6).
• Seccareccia D, Gebara N. Pruritus in palliative care. Can. Fam. Physician. Sep 2011;57(9):1010-1013.