Introduction

  • Pruritus can cause discomfort, frustration, poor sleep, anxiety and depression. Itch may be localised or due to systemic disease. Pruritus in systemic disease is often worse at night.
  • Some causes of pruritus are independent of histamine (uraemic pruritus), therefore antihistamine medication is often ineffective.
  • Persistent scratching, and the ‘itch-scratch-itch’ cycle, leads to skin damage, excoriation and thickening.
  • Patients with itch usually have dry skin.
  • Most medication can cause pruritic rash.

 

Assessment

Take a careful patient history:

  • offer skin examination looking for local and systemic causes as the cause may be multifactorial
  • primary skin disease (for example atopic dermatitis, contact dermatitis or psoriasis)
  • infection – candidiasis, lice, scabies, fungal infection
  • consider medication – opioids in particular codeine, morphine and diamorphine, selective serotonin re‑uptake inhibitors (SSRIs), ace inhibitors, statins, chemotherapeutic drugs, cytokines and monoclonal antibodies (refer to specific drug information)
  • consider investigations (full blood count, ferritin, c-reactive protein, urea and electrolytes, liver function tests, bone profile, thyroid function tests, blood glucose and chest X-ray)
  • Systemic diseases that can cause itch include:

 

  • cholestatic jaundice
  • iron deficiency +/-anaemia
  • chronic kidney disease
  • hepatitis
  • thyroid disease
  • lymphoma
  • hepatoma
  • diabetes
  • leukaemia
  • primary biliary cirrhosis
  • mycosis fungoides      
  • multiple myeloma
  • paraneoplastic
  • polycythaemia.

 

Management

General advice

  • Where possible treatment should be cause specific.
  • Treat underlying cause(s). Review medication to exclude a drug reaction.
  • Use an emollient liberally and frequently as a moisturiser.
  • Add an emollient to bath water and use emollient as a soap substitute (refer to local guidelines). All emollients improve dry skin which consequently improves itch. Some emollients contain specific antipruritic agents (refer to topical agents below).
  • Consider a sedating antihistamine, such as QThydroxyzine 25mg at night, if confident that the pruritic pathway is activated by histamine or if sleep disturbance remains despite other antipruritic measures.

 

Non pharmacological management

  • UVB phototherapy may help in uraemic pruritus.
  • Biliary stenting may relieve symptoms in cholestatic jaundice.

 

Pharmacological management – for systemic disease

The following table contains medication that may be recommended by a specialist. Please seek advice before initiating treatment.

Tables are best viewed in landscape mode on mobile devices

Cause

Treatment 1st line

2nd line

3rd line

Cholestasis

In cholestasis there is no evidence of one drug being more effective than another so the choice will depend on individual circumstances and local guidance

Rifampicin
300mg to 600mg once daily

Sertraline
50mg to 100mg once daily

Cholestyramine 4g up to four times daily

N/A

N/A

Uraemia

Gabapentin
100mg to 300mg daily - caution as accumulates in renal impairment

Dose and/or frequency may need adjustment

Naltrexone 50mg daily

Mirtazapine 15mg to 45mg daily - caution as accumulates in renal impairment and doses as low as 7.5mg may be suitable

Lymphoma

Prednisolone
10mg to 20mg three times daily

Cimetidine 400mg twice daily

Mirtazapine
15mg to 30mg at bedtime

Systemic opioid-induced pruritus

Chlorphenamine 4mg to 12mg (if benefit 4mg three times daily)

If no benefit switch opioid

QTOndansetron 8mg twice daily

Paraneoplastic

Paroxetine
5mg to 20mg once daily

Mirtazapine
15mg to 30mg at bedtime

 

Unknown

Chlorphenamine 4mg to 12mg (if benefit 4mg three times daily)

Paroxetine
5mg to 20mg once daily

Mirtazapine
7.5mg to 15mg at bedtime

 

Topical agents

  • Emollients or emollient with active ingredient (for example menthol 1%).
  • Crotamiton 10% cream (for example Eurax®) or capsaicin (0.025%) cream for localised itch.
  • Topical corticosteroid (mild to moderate potency) apply sparingly once daily for 2 to 3 days if the area is inflamed but not infected. Review after 7 days.
  • Lidocaine patches, review benefit after 3 days.
  • Be aware of the risk of fire when using emollients containing paraffin (refer to MHRA update).  

 

Practice points

  • Avoid topical antihistamines as they can cause allergic contact dermatitis.
  • Systemic treatment is often unnecessary if skin care improves symptoms.
  • Reserve systemic medication for patients who have persistent symptoms despite topical therapy.
  • Avoid vasodilators such as caffeine, alcohol, spices and hot water.
  • Ointments are better at relieving dry skin than creams or lotions, but take longer to be absorbed into the skin and may not be as well tolerated.

 

Resources

 

References

Alshammay SA, Duraisamy BP, Alsuhail A. Review of management of pruritus in palliative care. J Health Spec. 2016;4(1):17-23.

Clinical Knowledge Summaries. Itch - widespread. 2015 [cited 2018 Oct 03]; Available from: https://cks.nice.org.uk/itch-widespread.

Davis MP, Frandsen JL, Walsh D, Andresen S, Taylor S. Mirtazapine for pruritus. J Pain Symptom Manage. 2003;25(3):288-91.

Elsaie LT, El Mohsen AM, Ibrahim IM, Mohey-Eddin MH, Elsaie ML. Effectiveness of topical peppermint oil on symptomatic treatment of chronic pruritus. Clin Cosmet Investig Dermatol. 2016;9:333-8.

European Association for the Study of the Liver. EASL Clinical Practice Guidelines: management of cholestatic liver diseases. J Hepatol. 2009;51(2):237-67.

Hundley JL, Yosipovitch G. Mirtazapine for reducing nocturnal itch in patients with chronic pruritus: a pilot study. J Am Acad Dermatol. 2004;50(6):889-91.

MHRA.  2018.  Emollients: new information about risk of severe and fatal burns with paraffin-containing and paraffin-free emollients.  Available: https://www.gov.uk/drug-safety-update/emollients-new-information-about-risk-of-severe-and-fatal-burns-with-paraffin-containing-and-paraffin-free-emollients [Accessed 21 Jan 2019]

Primary Care Dermatological Society. Pruritus (without a rash). 2018 [cited 2018 Oct 03]; Available from:http://www.pcds.org.uk/clinical-guidance/pruritus-without-a-rash

Siemens W, Xander C, Meerpohl JJ, Buroh S, Antes G, Schwarzer G, et al. Pharmacological interventions for pruritus in adult palliative care patients. 2016 [cited 2018 Oct 03]; Available from:https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD008320.pub3/epdf/full

Twycross R, Wilcock A, Howard P. Palliative Care Formulary PCF6. 6th ed. England: Pharmaceutical Press; 2017.

Twycross R, Wilcock A, Toller CS. Symptom Management in Advanced Cancer. 4th ed. Nottingham: palliativedugs.com; 2009.