9th January 2024

Pruritus

Pruritis or itch is an unpleasant sensation of the skin or mucous membranes that elicits the urge to rub or scratch the area.

It is not as common in palliative patients as pain or breathlessness but can significantly affect quality of life.

The pathophysiology of pruritus is dependent on the cause and is often independent of histamine, e.g., uraemic pruritus, meaning antihistamines can have a limited role.

Assessment

Palliative patients may have multiple reasons for pruritus, so should be assessed for skin conditions like eczema and contact dermatitis, and infectious causes such as candidiasis or fungal infection should be excluded.

Medications should be reviewed as opioids, Penicillins, and cephalosporins can all contribute to pruritus. If any new medications have been started, drug reaction should be excluded.

Blood tests should be considered, and possible conditions contributing to pruritus are listed below:

• Full blood count – Polycythaemia, leukaemia, lymphoma, multiple myeloma
• Ferritin (If anaemic) – Iron deficiency
• Urea and electrolytes – Uraemia in renal failure
• Liver function tests – hepatic failure, cholestatic jaundice
• Bone profile – Hyperphosphatemia, hypercalcaemia
• Thyroid function – Hyperthyroidism
• HIV test – Pruritus can occur in up to 30% of those with HIV

Management of Pruritus

Conservative

• Ensure skin is not dry
• Soap substitutes and emollients
• Short fingernails
• Psychological support to help break cycle of itching and scratching

Pharmacological and Non-Pharmacological Management by Diagnosis

Sedating antihistamines like chlorphenamine, benzodiazepines or doxepin given at night can help with sleep. Other strategies may be appropriate depending on the cause, as shown in Table 1.

Source: Watson M, Campbell R, Vallath N, Ward S, Wells J. Oxford Handbook of Palliative Care. 3rd ed. Oxford University Press; 2019.