Pruritus
KEYPOINTS
- Pruritus can be described as an unpleasant cutaneous sensation which produces the desire to scratch
- Pruritus is relatively uncommon in advanced disease but can be very unpleasant and difficult to treat
- General non-pharmacologic treatment can be very helpful
- Generalised itching (often the child repeatedly rubbing the nose-tip) due to opioids is more common in children than adults
ASSESSMENT
(see Foreword)
- History should include the times at which the itching occurs (whether continuous and whether at night or day) its nature (burning, itching, etc.), location and relevant medication history
- Examination should include review of dryness of skin, possible presence of scabies, possible presence of jaundice
MANAGEMENT
General Measures
- Pruritus is often caused by dry skin, so a good first measure is a simple moisturiser cream
- Keep patient cool and use cool clothing
- Tepid (around 37°C) baths and showers (avoiding detergents), followed by gentle drying and application of moisturiser cream
- Keep nails short (filed not cut)
- Avoidance of alcohol and spicy foods
Topical Agents
- Menthol 1% and camphor 1% compounded in aqueous cream can be used several times a day as needed
Cause Specific Therapy
- Cholestasis
- Use general measures (see above)
- HI and H2 receptor blockers likely to be ineffective
- Place biliary stent (if possible and if patient’s general condition warrants this)
- The burden of investigation and treatment should always be weighed against the prognosis, the likely benefit of treatment and the patient’s wishes
- Cholestyramine 4 g 1-6 times/day PO to a maximum of 36 g/day
- Uraemia
- Use general measures (see above)
- HI and H2 receptor blockers likely to be ineffective
- Capcaisin 0.025% or 0.075% cream applied 3-5 times daily is useful where there is localised pruritus. Do not apply to large body areas
- Hodgkins Lymphoma
- Use general measures (see above)
- HI and H2 receptor blockers likely to be ineffective
- Radiation or chemotherapy where appropriate
- Corticosteroids e.g dexamethasone 4-8 mg daily
- If ineffective, substitute cimetidine 400 mg bid PO or ranitidine 150 mg bid PO
- Itch due to an opioid
- Use general measures (see above)
- HI and H2 receptor blockers likely to be ineffective
- May be transitory lasting a few days
- May be relieved by ‘switching opioids’
- Paroxetine 5 mg/day PO to 20 mg/day can be helpful
PITFALLS/CONCERNS
- Potential side effects of antihistamines may be agitation or confusion
PALLIATIVE TIPS
- Itching of the skin is present without obvious cause in over 50% of patients over 70 years
- Itching associated with cholestasis often starts on palms and soles and the severity is unrelated to the level of bile acids in skin
- H1 receptor blockers are useful in histamine based itch such as a drug reaction or urticaria
- Ondansetron is helpful when spinal opioids cause itching
- Antihistamine creams may cause a contact dermatitis
- Lidocaine cream may cause a contact dermatitis and worsening of itching
- Calamine cream may cause drying of the skin and worsening of the itching
SOURCES/REFERENCES
- Twycross R, Greaves MW, Handwerker H, Jones EA, Libretto SE, Szepietowski JC et al. Itch: scratching more than the surface. QJM 2003;96(1):7-26. http://www.ncbi.nlm.nih.gov/pubmed/12509645
- Zylicz Z, Twycross R, Jones A, editors. Pruritus in advanced disease. Oxford: Oxford University Press; 2004.
page revision: 16, last edited: 05 Oct 2009 20:38

