Pruritus/itch can be incredibly disruptive causing pain, insomnia and infection from excessive scratching.
Itch in palliative care falls into two groups – the cause will guide treatment:
- Histamine-induced: for example opioids or allergic dermatitis
- Non-histamine induced: for example cholestasis/jaundice or renal failure
Red flags
Don’t just prescribe an anti-histamine e.g. chlorphenamine (Piriton), without thinking about the cause. This will cause sedation without helping the itch if it is not histamine-induced.
Key clinical features for a clinician to assess in the community
- Review underlying diagnosis e.g. liver disease, renal failure, cancer
- Consider primary skin condition e.g. eczema/psoriasis or new scars
- Medication review e.g. opioids can cause itch but any new medication (e.g. antibiotics) could be the cause
- Signs or symptoms of common infection – e.g. candidiasis, scabies
An initial approach to treatment
- Stop offending drugs and consider alternative
- For opioid-induced itch try an anti-histamine (see table below)
- Blood tests: full blood count, ferritin, c-reactive protein, urea and electrolytes, liver function tests, bone profile, thyroid function tests
- Menthol 2%-5% in aqueous cream has the best evidence as counter-irritant but any emollient may help
- Consider a sedating antihistamine, such as Hydroxyzine 25mg at night, if confident that the pruritis is mediated by histamine release
Specific treatments according to cause
|
Cause |
Initial approach to treatment |
|
Opioid induced itch mediated by histamine release Other medicines e.g. antibiotics |
Anti-histamine such as:
Consider: switch to different opioid Consider: Ondansetron up to 4-8mg b.d. (constipating) |
|
Cholestatic jaundice |
Itch is not histamine related Consider: Biliary stenting |
|
Chronic kidney disease->uraemia |
Itch is not histamine related |
|
Lymphoma/leukaemia |
Steroids can reduce lymphoma itch dramatically e.g. Dexamethasone 4mg-8mg Consider: Cimetidine 400mg b.d. |
|
Paraneoplastic |
Localised:
Generalised:
|
|
Candida |
Treat systemically or locally according to distribution |
|
Unknown |
Chlorphenamine or Loratidine |
If none of the above help, then speak to your local palliative care team for more ideas.