Itch associated with cancer
Some cancers (eg biliary tract cancers, skin cancers, Hodgkin lymphoma) are associated with itch; the mechanism for this phenomenon is unknown.
Itch can also be related to some cancer treatments—see Skin reactions from cancer treatment in palliative care.
Advise general skincare measures in addition to the specific therapies below.
For itch associated with haematological cancer (eg Hodgkin lymphoma), consult with the patient’s haematologist before prescribing oral corticosteroids because corticosteroids can affect biopsy results. If dexamethasone is considered appropriate, use:
dexamethasone 4 to 8 mg orally, daily. Assess after 1 week and stop if there is no benefit. If there is benefit, reduce to the lowest effective dose and use for the shortest possible time. For advice on stopping dexamethasone, see Rationalising corticosteroids used for symptom or complication management in palliative careTwycross, 2003. dexamethasone
For itch associated with skin cancer, consider a nonsteroidal anti-inflammatory drug (NSAID). If the NSAID is not effective after 1 week, stop it and consider trialling another NSAID. For dosages, see Nonsteroidal anti-inflammatory drugs.
For itch associated with a malignant solid tumour, consider:
1paroxetine 10 to 20 mg orally, at nightMillington, 2018Scottish Palliative Care Guidelines, 2020Siemens, 2016 paroxetine
OR
2mirtazapine 15 to 30 mg orally, at nightMillington, 2018Scottish Palliative Care Guidelines, 2020. mirtazapine
Assess the effectiveness of drug therapy and consider stopping paroxetine or mirtazapine if no benefit is apparent after 1 week, or sooner if the patient experiences undesirable adverse effects.
If the above therapy is ineffective, an antihistamine may be useful; see Undifferentiated or other causes of itch in palliative care.
Aprepitant may improve itch associated with cancer and cancer treatment (particularly biological immunomodulatory drugs), but its use may be prohibited by cost.
For other aspects of palliative care for patients with cancer, see Principles of palliative care for cancer.