British Association of Dermatologists Guidelines for Generalised pruritus

British Association of Dermatologists has come out with fresh clinical Guidelines for Generalised pruritus which have been endorsed by NICE.The focus of these guidelines is the investigation and management of both noncutaneous secondary causes of pruritus due to an underlying disorder, and Generalised Pruritus of Unknown Origin forming about 8% of all cases of pruritus.The present guidelines are exhaustive and supersede previous guidelines.

Causes of generalized pruritus without rash-

1. Pruritic skin diseases before rash


2. Disorders of iron metabolism


3. Uraemia


4. Hepatic disease (especially cholestasis)


5. Malignancy


6. Haematological disorders


7. Infection


8. Endocrine disease


9. Neurological disorders


10. Psychological and emotional factors


11. Adverse drug reactions


12. Heart failure


13. Pregnancy


14. Pruritus of elderly skin


15. Pruritus of unknown origin (GPUO)

A.Iron deficiency and pruritus

Recommendation

Full blood count and ferritin levels should be checked in all patients with chronic GPWOR (Strength of recommendation C; Level of evidence 2++)

B.Iron overload

Recommendation

• Liver functions tests should be considered for patients with generalized pruritus associated with iron overload (Strength of recommendation D; Level of evidence 3)

C.Haematological causes of pruritus

Recommendations (investigation)

• Patients with generalized pruritus with suspicion of haematological involvement should have initial investigations including full blood count, blood film, lactate dehydrogenase and ESR (if available). Immunoglobulins and urinary paraproteins may also be requested, but will have a low yield, as myeloma is rarely associated with GPWOR (Strength of recommendation D; Level of evidence 3)


• Patients with generalized pruritus associated with either PV or suspected Hodgkin lymphoma should be referred to haematology (Strength of recommendation D; Level of evidence 4)


• Patients with generalized pruritus with suspicion of PV (raised haemoglobin or haematocrit) should have blood samples sent for JAK2 V617F mutation analysis and/or be referred to haematology (Strength of recommendation D; Level of evidence 4)


• In the absence of JAK2 mutation, secondary causes of PV should be investigated by means of clinical assessment, renal and liver function tests, serum erythropoietin level, measurement of oxygen saturation, chest X-ray and abdominal ultrasound (Strength of recommendation D; Level of evidence 4)

Recommendations (treatment)

• Patients with generalized pruritus associated with lymphoma may have their itch resolved by treatment with cimetidine, gabapentin, carbamazepine, mirtazapine or phototherapy (Strength of recommendation D; Level of evidence 3)


• Patients with generalized pruritus associated with incurable lymphoma may have their itch relieved with oral corticosteroids (Strength of recommendation D; Level of evidence 4)


• Patients with generalized pruritus associated with PV may have their itch relieved with cytoreductive therapy, aspirin, interferon-α, SSRIs, PUVA, UVB phototherapy, cimetidine or atenolol (Strength of recommendation D; Level of evidence 3)

D.Pruritus associated with malignant solid tumours

Paraneoplastic pruritus -

Main Recommendations

• If paraneoplastic pruritus is suspected, investigations should be guided by a thorough, regular history and physical examination, although a full investigation to rule out malignancy is not routinely recommended (Strength of recommendation D; Level of evidence 3)


• Pruritus with systemic symptoms of malignancy needs tailored investigations to rule out specific cancers (Strength of recommendation D (GPP); Level of evidence 4)


• Oncology patients receiving biological and other therapies should be asked about pruritus on review (Strength of recommendation A; Level of evidence 1+)
  Recommendations (treatment)


• Paraneoplastic pruritus may be relieved with paroxetine, mirtazapine, granisetron or aprepitant (Strength of recommendation D; Level of evidence 3)


• The management of paraneoplastic pruritus in the palliative care setting may include a wider range of therapies, such as thalidomide (Strength of recommendation D; Level of evidence 3)

Endocrine causes of generalized pruritus

Recommendations (investigation)

• Patients with generalized pruritus should not undergo routine endocrine investigations (including TFTs) unless they present with additional clinical features suggesting diabetes, other endocrinopathy or renal disease (Strength of recommendation D; Level of evidence 3)


• Vitamin D supplementation may help some people affected by GPWOR (Strength of recommendation D; Level of evidence 3)

Uraemic pruritus

Recommendations (investigation)

• Urea and electrolytes should form part of the investigation of GPUO (Strength of recommendation D; Level of evidence 3)

Recommendations (treatment)

• Ensure adequate dialysis, normalize calcium–phosphate balance, control PTH to accepted levels, correct any anaemia with erythropoietin and use simple emollients (for xerosis) in patients with uraemic pruritus before using other treatment strategies (Strength of recommendation D; Level of evidence 3)


• No single topical or systemic treatment strategy is effective:
  
  
  
  • ○Consider capsaicin cream, topical calcipotriol or oral gabapentin (Strength of recommendation D; Level of evidence 3)
  
  
  • ○Sedative antihistamines long term may predispose to dementia and should be avoided, except in palliative care (Strength of recommendation B; Level of evidence 2++)
  
  
  • ○Cetirizine is not an effective antihistamine in uraemic pruritus (Strength of recommendation D; Level of evidence 3)
  
  
  
  


• Renal transplantation is the only definite treatment.

Hepatic pruritus

Recommendations (investigation)

• Liver function tests should form part of the investigation of GPWOR. Perhaps consider bile acids and antimitochondrial antibodies. Any suggestion of significant hepatic impairment should lead to a referral to a hepatology centre (Strength of recommendation D; Level of evidence 3)

Recommendations (treatment)

• In patients with hepatic pruritus, consider rifampicin as first-line treatment (Strength of recommendation A; Level of evidence 1+)


• In patients with hepatic pruritus consider cholestyramine as second-line treatment (Strength of recommendation D (GPP); Level of evidence 4)


• In patients with hepatic pruritus consider sertraline as third-line treatment (Strength of recommendation D (GPP); Level of evidence 4)


• Naltrexone or nalmefene are considered fourth-line treatments (Strength of recommendation D (GPP); Level of evidence 4)


• In patients with hepatic pruritus consider as fifth-line treatment
  
  
  
  • ○systemic dronabinol, phenobarbitone, propofol or topical tacrolimus ointment (Strength of recommendation D; Level of evidence 3)
  
  
  • ○new specific agents based on blockade of bile acid transport, autotaxin and lysophosphatidic acid metabolism (Strength of recommendation D; Level of evidence 4)
  
  
  • ○phototherapy, extracorporeal dialysis techniques, nasobiliary drainage and liver transplantation (Strength of recommendation D; Level of evidence 3)
  
  
  
  


• In patients with hepatic pruritus do not use gabapentin (Strength of recommendation D (GPP); Level of evidence 4)

Neuropathic pruritus

Recommendations (investigation)

• Following a detailed history, examination and initial investigations, a patient with neuropathic pruritus may need to be referred to the relevant specialist (Strength of recommendation D (GPP); Level of evidence 4)


• Detailed further investigation of the nervous system is advised only if it is clinically indicated (Strength of recommendation D (GPP); Level of evidence 4)

Recommendations (treatment)

• Patients with neuropathic pruritus should be referred to the relevant specialist for treatment (Strength of recommendation D (GPP); Level of evidence 4)

Psychological and emotional factors in pruritus

Recommendations (treatment)

• In distressed patients with chronic pruritus including likely psychogenic origin, consider psychosocial and behavioural interventions including education on how to avoid trigger factors, how to apply treatments, lifestyle interventions, relaxation techniques, cognitive restructuring and behaviour modification including habit reversal training (Strength of recommendation D (GPP); Level of evidence 4)


• Patient support groups can be beneficial (Strength of recommendation D (GPP); Level of evidence 4)


• Referral to social workers, liaison psychiatry and psychologists may be helpful in individual cases (Strength of recommendation D (GPP); Level of evidence 4)

Infections, infestations and generalized pruritus

Recommendations (investigation)

• Take a full history (including travel history, sexual history and history of potential intravenous drug abuse) and examination; consider:
  
  
  
  • ○HIV, hepatitis A, B and C serology
  
  
  • ○Screening for malaria, strongyloidiasis and schistosomiasis (Strength of recommendation D (GPP); Level of evidence 4)
  
  
  
  

Recommendations (treatment)

• In patients with generalized pruritus associated with HIV consider indomethacin 25 mg three times per day, orally (Strength of recommendation D; Level of evidence 3)


• In patients with generalized pruritus associated with HIV consider hypnosis to relieve itch (Strength of recommendation D; Level of evidence 3)

Drug-induced pruritus

Recommendations (investigations)

• In patients with drug-induced pruritus, a trial of cessation of medications should be undertaken if the risk vs. benefit analysis is acceptable to both clinician and patient (Strength of recommendation D (GPP); Level of evidence 4)

Recommendations (treatment)

• Naltrexone is effective in treating opioid-induced generalized pruritus without visible skin signs and is the first-choice recommendation in this situation (if cessation of opioid therapy is impossible). Methylnaltrexone may be an alternative (Strength of recommendation B; Level of evidence 1+)


• In patients with opioid-induced generalized pruritus without visible skin signs consider methylnaltrexone, ondansetron, droperidol, mirtazapine or gabapentin as alternative antipruritic agents (Strength of recommendation D (GPP); Level of evidence 4)


• In patients with postoperative generalized pruritus without visible skin signs consider diclofenac given rectally (Strength of recommendation D (GPP); Level of evidence 4)


• In patients with chloroquine-induced generalized pruritus without visible skin signs consider prednisolone 10 mg, niacin 50 mg or a combination of prednisolone and niacin (Strength of recommendation D (GPP); Level of evidence 4)

In patients with chloroquine-induced generalized pruritus without visible skin signs consider dapsone to relieve itch(Strength of recommendation D (GPP); Level of evidence 4)

Treatment of generalized pruritus of unknown origin

Local Treatment of generalized pruritus of unknown origin

Recommendations

• Patients with GPUO may be prescribed topical doxepin. Treatment should be limited to 8 days, 10% of body surface area and 12 g daily (Strength of recommendation D (GPP); Level of evidence 4)


• Patients with GPUO may benefit from topical clobetasone butyrate or menthol (Strength of recommendation D; Level of evidence 4)


• Patients with GPUO should not use crotamiton cream (Strength of recommendation B; Level of evidence 1+)


• Patients with GPUO should not use topical capsaicin or calamine lotion (Strength of recommendation D (GPP); Level of evidence 4)

Systemic Treatment of generalized pruritus of unknown origin

Recommendations

• In patients with generalized pruritus no one therapy has been found to be effective and safe. Consider the following to relieve itch:
  
  
  
  • ○nonsedative antihistamines such as fexofenadine 180 mg, loratadine 10 mg or mildly sedative agents such as cetirizine 10 mg before sedative antihistamines (Strength of recommendation D; Level of evidence 2+)
  
  
  • ○paroxetine, fluvoxamine, mirtazapine, naltrexone, butorphanol, gabapentin, pregabalin, ondansetron or aprepitant (Strength of recommendation D; Level of evidence 3)
  
  
  • ○H₁ and H₂ antagonists in combination, for example fexofenadine and cimetidine (Strength of recommendation D (GPP); Level of evidence 4)
  
  
  • ○sedative antihistamines in the short-term or palliative setting, for example hydroxyzine (Strength of recommendation D; Level of evidence 3)
  
  
  
  

For further reference log on to : https://doi.org/10.1111/bjd.16117