Chronic pruritus

Pruritus (lat. prurigo ) is defined as an unpleasant sensation of skin leading  to the desire to scratch ( itch )

Common dermatological problem Often intractable with a high impact on quality of life Increases with age Estimated that 60 % of people > 65 suffer from mild to severe occasional pruritus each week Exact prevalence is not known Can be caused by both skin and systemic problems International forum for the study of Itch has suggested a classification which considers clinical as well as differential diagnostic reasons

Systemic causes- Metabolic and Endocrine ♦ Chronic renal insufficiency ♦ hyperparathyroidism ♦ hyper & hypothyroidism ♦ Carcinoid syndrome ♦ Diabetes  Hepatic ♦ PBC ♦ Extrahepatic biliary obstruction ♦ Cholestasis of pregnancy ♦ Hepatitis ♦ Oral contraceptives ♦ Drug ingestion  Infective disease ♦ HIV and AIDS ♦ Parasitoses including Helminthosis  Haematological ♦ Polycythemia vera ♦ Myelodisplastic syndrome ♦ Lymphoma eg Hodgkins lymphoma ♦ Multiple myeloma ♦ Iron deficiency  Neurological disorders ♦ Multiple sclerosis ♦ Brain tumours ( eg gliomas ) ♦ Notalgia paraesthetica ♦ Brachioradial pruritus ♦ Peripheral neuropathy  Psychiatric or Psychosomatic diseases ♦ Depression ♦ Affective disorders ♦ Hallucinosis ♦ OCD ♦ Schizophrenia ♦ Eating disorders 

Dermatological causes-Xerosis Scabies Dermatitis herpetiformis Atopic dermatitis Lichen simplex Psoriasis Lichen planus Contact dermatitis Miliaria Drug reactions Insect bites Pruritic urticarial papules and plaques of pregnancy Peduculosis Urticaria Folliculitis Sunburn Polymorphous light eruption Bullous pemphigoid Pemphigus foliaceus Pityriasis rosea Fiberglass dermatitis Fungal infections Mycosis fungoides Seborrhoeic dermatitis

history-Onset , duration Intensity Timing Itch characteristic for eg prickling crawling burning Rash ? Site eg entire skin palpebral conjunctiva perianal / perogenital ear canals , eyelids, nostrils Associated symptoms Disturbing sleep ? Relieving factors Medical history Drug history , cosmetics , creams ? Blood transfusions Others itching ? ( scabies ) Alcohol abuse , sexual hx , drug abuse Dietary history  

Examination Assess severity for eg using an visual analogue score ( VAS ) Skin examination Mucous membranes Scalp Hair Nails Anogenital region Distribution of primary and secondary skin lesions Skin signs of systemic disease Palpation of liver , kidneys , spleen and lymph nodes Mental state – psychological impact

Testing- Renal function FBC , ESR LFTs , Bone profile , Vit D , Bl glucose , HbA1c TFTs Iron studies Blood morphology , LDH ANA HIV and hepatitis A, B and C serology Electrophoresis IgE serum levels ( total and sllergen specific ) Stool test for ova , parasites or blood Prick tests with specific allergens Microscopy of skin scrapings Dermoscopy Skin biopsy CXR CT scan of neck , thorax , abdomen and pelvis MRI of brain and spinal cord Red flags-Bullous pemphigoid Hodgkins lymphoma Polycythemia vera HIV Infection / AIDS Paraneoplastic pruritis Brain tumour Stroke

management- Where possible manage underlying cause Discontinue drugs where possible Emollients with active ingredients for eg Menthol 0.5 % or 1 % , phenol or camphor Treat skin infections Topical therapy Capsaican particularly renal ( poor pt compliance ) , topical doxepin , crotamion cream Systemic therapy ( seek adv from dermatology where appropriate ) ♦ sedating anti-histamines eg hydroxyzine ( Atarax ) 10-25 mg nocte ♦ Non sedating anti histamines eg Fexofenadine 180 mg ♦ Anti-depressants eg Tricyclics ( amitriptyline , doxepin ) , SSRIs  ( paroxetine ) , Mirtazepine @ 15 mg ♦ Anti-convulsants and pain modulators – eg gabapentin or pregabalin ♦ Opioid receptor antagonists ; agonists eg Naltrexone ♦ Rifampicin ( hepatic pruritus ) , Cholestyramine ♦ Ondansetron , NSAIDs , H1 and H2 antagonists in combination for eg fexofenadine and cimetidine UV phototherapy Psychosomatic therapy

LINKS AND RESOURCES

British Association of Dermatologists leaflet on pruritus http://www.bad.org.uk/shared/get-file.ashx?id=121&itemtype=document

Medline Plus – information for patients https://medlineplus.gov/itching.html

NHS information for patients on pruritus with some do’s and dont’s https://www.nhs.uk/conditions/itchy-skin/

NHS inform Scot – a comprehensive section on itching https://www.nhsinform.scot/illnesses-and-conditions/skin-hair-and-nails/itching

Pruritus ( without rash ) guidance on management for doctors from PCDS http://www.pcds.org.uk/clinical-guidance/pruritus-without-a-rash

Dermnet NZ-on pruritus https://dermnetnz.org/topics/pruritus/

BAD guideline –British Association of Dermatologists’ guidelines for the
investigation and management of generalized pruritus in
adults without an underlying dermatosis, 2018 http://www.bad.org.uk/shared/get-file.ashx?id=5927&itemtype=document

European S2k guideline on Chronic Pruritus https://www.ncbi.nlm.nih.gov/pubmed/30931482

full text available from https://www.medicaljournals.se/acta/content_files/files/pdf/99/5/5431.pdf

References

European Dermatology Forum Update of the guideline on Chronic Pruritus accessed via www.medicaljournals.se
BMJ Best Practice Assessment of pruritus
Pruritis : causes and management July 2006 / midlife and beyond/ geriatric medicine
Pruritis Scott Moses MD AFP Sept , 2003 / Volume 68 , Number 6
Management of itching Abhishek Sharma et al JIACM 2009 ; 10 (3) : 119-27
Chronic Pruritus ; Clinics and Treatment Sonja Grundmann , MD et al Department of Dermatology , Neurodermatology and Competence Center Chronic Priritus , University Hospital Munster , Munster , Germany
Itch widespread CKS NHS Nov 2015
Chronic Pruritus in the Geriatric Population Dermatolgic Clinics Cao , Taige , MD et al
Understanding Pruritus in Systemic Disease Journal of Pain and Symptom Management Vol . 21 No 2 February 2001
British Association of Dermatologists Guidelines for the investigation and management of generalized pruritus in adults without an underlying dermatosis
Grundmann, Sonja, and Sonja Ständer. “Chronic pruritus: clinics and treatment.” Annals of dermatology vol. 23,1 (2011): 1-11. doi:10.5021/ad.2011.23.1.1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119985/
Arnold DL, Krishnamurthy K. Lichen Planus. [Updated 2020 Mar 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526126/
Augustin, M., Wilsmann‐Theis, D., Körber, A., Kerscher, M., Itschert, G., Dippel, M. and Staubach, P. (2019), Diagnosis and treatment of xerosis cutis – a position paper. JDDG: Journal der Deutschen Dermatologischen Gesellschaft, 17: 3-33. doi:10.1111/ddg.13906
( abstract )
Itch:a symptom of occult disease Navaz Hiramanek Australian Family Physician Vol. 33, No. 7, July 2004 4 495
Cohen, Kenneth R et al. “Pruritus in the elderly: clinical approaches to the improvement of quality of life.” P & T : a peer-reviewed journal for formulary management vol. 37,4 (2012): 227-39. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351862/
Nowak, Dominik A, and Jensen Yeung. “Diagnosis and treatment of pruritus.” Canadian family physician Medecin de famille canadien vol. 63,12 (2017): 918-924. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5729138/#
Underlying systemic causes of itch LACapaldi, 2JD Bernhard J R Coll Physicians Edinb 2008;38:53–5 2008 Royal College of Physicians of Edinburgh
Pereira, Manuel P.^a; Steinke, Sabine^a; Bruland, Philipp^b; Ständer, Hartmut F.^c,d; Dugas, Martin^b; Augustin, Matthias^e; Ständer, Sonja^a Management of chronic pruritus: from the dermatological office to the specialized itch center: a review, Itch: September 2017 – Volume 2 – Issue 2 – p e6 doi: 10.1097/itx.0000000000000006 ( Abstract )
British Association of Dermatologists’ guidelines for the investigation and management of generalized pruritus in adults without an underlying dermatosis, 2018 G.W.M Millington et al British Journal of Dermatology (2018) 178, pp34–60
Rajagopalan, Murlidhar et al. “Diagnosis and Management of Chronic Pruritus: An Expert Consensus Review.” Indian journal of dermatology vol. 62,1 (2017): 7-17. doi:10.4103/0019-5154.198036
Weisshaar E, Matterne U. Epidemiology of Itch. In: Carstens E, Akiyama T, editors. Itch: Mechanisms and Treatment. Boca Raton (FL): CRC Press/Taylor & Francis; 2014. Chapter 2. Available from: https://www.ncbi.nlm.nih.gov/books/NBK200924/
Pruritus in Systemic Diseases: A Review of Etiological Factors and New Treatment Modalities Nagihan Tarikci,¹ Emek Kocatürk,¹ Şule Güngör,¹ Ilteriş Oğuz Topal,¹ Pelin Ülkümen Can,¹ and Ralfi Singer The Scientific World Journal Review Article | Open Access Volume 2015 |Article ID 803752 | 8 pages | https://doi.org/10.1155/2015/803752

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