CliniCal REVIEW Nodular : An overview of diagnosis and management

Sheila Ryan

aBSTRaCT Nodular prurigo is a chronic inflammatory skin disease characterised by severe pruritus, nodules, papules, excoriations and ulceration. It is a can be a very distressing disorder for the sufferer. The condition is linked with a variety of disorders including atopic eczema, chronic renal failure, hyperthyroidism, iron deficiency anaemia, obstructive biliary disease, gastric malignancy, lymphoma, leukaemia, hepatitis B and C, HIV and depression. Nodular prurigo affects all ages and commonly occurs between the ages of 20 to 60 years. There are a range of treatments available for nodular prurigo, but their use is based on anecdotal rather than empirical evidence. The range of treatments will be discussed here. The nurse has an important role in guiding and supporting patients with this difficult, often frustrating condition.

Citation: Ryan S. Nodular prurigo: An overview of diagnosis and management. Dermatological Nursing 2017. 16(4): 18-21

Introduction of disorders including atopic eczema, Nodular prurigo is a chronic chronic renal failure, hyperthyroidism, iron infl ammatory skin disease characterised defi ciency anaemia, obstructive biliary  by severe pruritus, nodules, papules, disease, gastric malignancy, lymphoma,  excoriations and ulceration.1 Dr James leukaemia, hepatitis B and C and HIV.1,4  Hyde fi rst described the condition in If nodular prurigo is solely as a result of 1909, which reported pruritic nodules  scratching it is remarkable that it does on the lower extremities in middle-aged not evolve in more patients with chronic  women.2 The condition is also known pruritic conditions.3 as , Hyde’s disease, chronicus, lichen obtusus Nodular prurigo is also linked corneus and nodular neurodermatitis with psychiatric disorders including circumscripta.1 depression and anxiety.3 The relationship here is also unclear. Aetiology There is debate within the literature The cause of nodular prurigo is poorly whether there is an increased risk understood. It is not clear whether the of developing nodular prurigo in condition is solely the result of chronic psychiatric conditions. scratching or a disease in itself.3,4 Nodular Notwithstanding, there is also prurigo is associated with a variety evidence that while there is a higher

Table 1. Associated Disorders

Classifi cation Associated diseases Dermatological Atopic eczema, psoriasis, bullous pemphigoid, linear IgA, scabies, T-cell lymphoma Internal disorders Anaemia, kidney disease, cholestatic disorders, diabetes, polycythaemia vera, HIV, hepatitis B and C, lymphoma and malignancies Sheila Ryan is a Registered Advanced Nurse Practitioner at the Department Neurological Notalagic paraesthecia, multiple sclerosis, of Dermatology, University of Limerick Psychosomatic/psychiatric Parasitosis, depression, schizophrenia Hospital Group, Limerick, Ireland.

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incidence of psychiatric co-morbidities Nodular prurigo will rarely resolve are usually suffi cient for diagnosing the in individuals with nodular prurigo spontaneously.8 condition.10 The fi rst step is to exclude than healthy controls, the same any underlying disease and then to incidence is seen when compared Diagnosis and differential diagnosis address cause of general pruritus.10 with patients with other pruritic The clinical features of nodular prurigo Potential investigations include: dermatoses.5

It is thought that there is a cascade of events in developing nodular prurigo.1 The condition starts with chronic and severe pruritus. This in turn induces mechanical trauma through scratching. This subsequently leads to the recruitment of a lymphocyte rich infl ammatory infi ltrate, tissue modelling and the activation as well as proliferation of peripheral nerves.1

Epidemiology Nodular prurigo affects both sexes equally. The commonest age is 20 to 60 years. However the condition does affect children.6 Nodular prurigo at a younger age is more commonly Figure 1 associated with atopic eczema.4 Localised nodular prurigo Clinical Presentation The patient will have a longstanding chronic pruritus.7 The patient will complain of an intense severe in the area affected by nodular prurigo. Nodular prurigo lesions are fi rm papules/nodules that are ≤2cm in diameter (Figure 1). The lesions may be warty, scally, excoriated, or crusted, and may number from a few to hundreds (Figure 2).

Nodules often start as a red, itchy lump.8 Older lesions can be grey/ purple in colour and are sometimes hyperkeratotic, or ulcerated (Figure 3).1 The skin between lesions is usually normal, but can be dry or lichenifi ed.8 The lesions tend to be distributed symmetrically and affect the extensor surfaces of arms, legs.8 The back, abdomen, buttocks and posterior neck are also frequently affected.4 However the face, palms and fl exural areas are rarely affected.4

Typically, the middle back is spared as the patient often cannot reach this site.1 This is sometimes referred to as the butterfl y sign and is a classic Figure 2 feature of nodular prurigo.1 Generalised nodular prurigo

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where there is underlying xerosis.9 Dry skin is a well-known cause of pruritus. Therefore, patient education on soap avoidance and an effective emollient regime is important to reduce symptoms 8 Menthol based creams or ointments. These can be helpful in some cases. These creams and ointments can cool the skin, but the effects are temporary. It is often best used in limited disease 8 Capsaicin cream. This may also be effective, but it needs to be applied 4-6 times daily for at least 2 weeks and for up to 10 months.11 Figure 3 Capsaicin is made from chilli Eroded nodular prurigo pepper and it induces a burning sensation initially before it helps 8 Pruritus screen – full blood management is often the best method with itch.4 Due to the frequency of count, CRP, iron studies, urea and of treating the nodular prurigo application and the initial burning electrolytes, liver function tests, symptoms.4 Where this is not possible, sensation it is most effective in thyroid function tests, calcium and treatments that alleviate pruritus or limited disease glucose.7 These investigations will reduce scratching behaviour can be 8 N-acetylcysteine. This has help identify any underlying renal, used to treat the nodular prurigo recently shown to be effective liver, metabolic or infective cause.7 symptoms. in atopic eczema and other 8 HIV, hepatitis B and C screen.4 pruritic conditions such as nodular 8 Patch testing to identify contact Simple measures such as advising prurigo.12 It is available as an oral .7 the patient on keeping nails short, and topical medicine. Topically it is 8 Skin biopsy of lesions in atypical wearing cotton gloves and keeping a N-acetylcysteine 10% in 5% urea. presentation.7 bathing water temperature lukewarm This formulation is malodorous are useful fi rst steps. Advising the with a sulphur smell. This odour In patients with severe disease, patient to limit exposure of pruritic can be improved with the addition where a cause cannot be determined skin to the air is also a useful tip. of 1.5% lavender, orange or potential malignancy should be out Nodular prurigo lesions are often rosemary oil ruled.4 more itchy when the skin is exposed. 8 Topical steroids. These are useful Also, when the skin is exposed, the in treating both localised and The differential diagnosis for pruritic areas are more accessible extensive nodular prurigo lesions. nodular prurigo includes dermatitis for scratching. Educating the patient They generally need to potent herpetiformis, scabies, lichen simplex on the role of scratching and the (e.g. betamethasone valerate 0.1%) chronicus, atopic eczema, allergic production of nodular prurigo or very potent (e.g. clobetasol , hypertrophic lesions is of paramount importance. propionate) to be effective. lichen planus, perforating disorders, The nurse, as a skilled educator, has However, their long-term use is neurotic excoriations and multiple an important role in guiding and limited due to the potential for keratoacanthomas, dermatofi broma.4 encouraging patients undergoing skin atrophy.4 Steroid impregnated treatment. dressings (e.g. fl udroxycortide Management impregnated tape) can be used as Nodular Prurigo is a diffi cult condition Local treatments it is both anti-infl ammatory and to treat. The evidence for the majority There are a variety of local protective. Its use is restricted to of treatments is based on anecdotal treatments. The advantage of a local localised disease evidence rather than empirical studies. treatment is the relative low toxicity. 8 Intralesional steroid injections In the main treatments are aimed at The disadvantage is they are often (triamcinolone acetonide). These reducing or stopping the itch scratch restricted to local disease and the time are useful in treating resistant cycle. consuming nature of these treatments. localised lesions. They are anti- These treatments include: infl ammatory and the lesion will General measures 8 Emollients. These should be used usually fl atten within weeks of Where there is an identifi ed regularly to cool and moisturise treatment. If effective, treatment underlying associated cause, its the skin. This is especially important can be repeated at 4 weekly

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intervals. However, the treatment is effective than non-sedating in 2. Hyde JN. Prurigo Nodularis. In Hyde painful and is further limited by the the management of nodular JN, Montgomery FH, A practical treatise potential for skin atrophy prurigo. The benefi t of sedating on disease of the skin, for the use of students and practitioners 3rd ed. Lea & Febiger, 8 Occlusive dressings. These limit antihistamines is that they help with Philadelphia. 1909:174-5 access to the nodular prurigo sleep, which can be problematic in lesions and are therefore an nodular prurigo1 3. Zeidler C, Stander S. The pathogenesis 8 of prurigo nodularis - “Super-itch” in effective treatment option. They 8 Antidepressants. Tricyclic exploration. European Journal of Pain 2016. vary from hydrocolloid dressings antidepressants such as 20(1):37-40 (e.g. Duoderm), impregnated amitriptyline and doxepin have a 4. Saco M, Cohen G. Prurigo Nodularis: dressings (e.g. Viscopaste, Zipzoc) benefi cial anti-pruritic effect, which Picking the right treatment. The Journal of to wet wraps. Their effectiveness is helps alleviate the symptoms of Family Practice 2015. 64(4):221-226 increased when used with topical nodular prurigo.1 Both drugs are 5. Schneider G, Hockmann J, Stumpf steroids used at lower dosages than they A. Psychosomatic aspects of prurigo 8 Cryotherapy. This is useful when are used in psychiatry. It is useful nodularis. Hautarzt 2014. 65(8):704-708 it comes to treating isolated to explain to the patient that these thickened lesions.9 It is thought drugs are being used for their 6. Amer A, Fischer H. Prurigo Nodularis in a 9 year old girl. Clinical Pediatrics 2009. to cause localised destruction of benefi cial effects on the nerve 48(1):93-5 sensory nerves and thus reduce endings in the skin, rather than for pruritic symptoms.9 A gentle their antidepressant properties 7. Knott L. Prurigo Nodularis, Patient 2016, Available at https://patient.info/ freeze thaw cycle, e.g. 10 second 8 Thalidomide is effective in treating doctor/prurigo-nodularis-pro [Accessed single freeze, is often suffi cient. refractory nodular prurigo.15 November 2017] This can be repeated at monthly However, the drug is notoriously 4 8. Prak A, Dela Rosa KM, Hogan DJ, intervals teratogenic. The drug can also Flowers F, Mason SH, Hruby SM, Mason 15 8 Phototherapy, narrow band UVB cause peripheral neuropathy. SM. Prurigo Nodularis. Medscape 2017. and PUVA. These have also been Therefore, nerve conduction Available at https://emedicine.medscape. shown to be effective in treating studies prior to and during com/article/1088032-overview [Accessed nodular prurigo.9 It is especially treatment are recommended. November 2017] useful in treating extensive disease. 9. Lee MR, Shumack S. Prurigo Nodularis: A It is thought that UV radiation has Conclusion review. Australasian Journal of Dermatology an antipruritic effect by inhibiting Nodular prurigo is a very distressing 2005. 46:211-220 mast cells.13 The major disadvantage , which has a signifi cant 10. Lotti T, Buggiani G, Prignano F. to this treatment is the diffi culty impact on an individual’s quality of life. Prurigo nodularis and lichen simplex in traveling for this hospital-based It is strongly associated with a range chronicus. Dermatologic Therapy 2008. treatment of medical conditions, which cause 21:42-46 8 Habit reversal. This can be used chronic pruritus. This adds signifi cantly 11. Stãnder S, Luger T, Metze D. Treatment in conjunction with all the above to the diffi culty in managing the of prurigo nodularis with topical capsaicin. treatments or in isolation. It is a condition. This problem is further Journal of the American Academy of Dermatology 2001. 44:471-478 behaviour modifi cation programme propounded by the lack of robust where the patient is taught not research into treatment strategies. 12. Grant JE, Chamberlain SR, Redden SA, to respond by scratching to Leppink EW, Odlaug BL, Kim SW. 14 N-Acetylcysteine in the treatment of pruritus. The technique teaches Due to the complexity, it means excoriation disorder; a randomized clinical the patient about the importance there are a wide range of treatments trial. JAMA Psychiatry 2016. 73(5): of optimising therapy, being aware available for the patient – and this 490- 496 of exacerbating factors and of their can be diffi cult and confusing. The 13. Tamagawa-Mineoka R, Katoh N, Ueda scratching behaviour. This increased nurse has an important role in the E, Kishimoto S. Narrow-band ultraviolet B awareness and knowledge then management and treatment, and phototherapy in patients with recalcitrant aids the patient in reducing their can guide the patient through the nodular prurigo. Journal of Dermatology scratching. various treatment options as well as 2007. 34(10):691-695 supporting the patient in managing this 14. Grillo M, Long R, Long D. Habit Systemic treatments diffi cult condition. DN reversal training for the itch-scratch The majority of systemic treatments cycle associated with pruritic conditions. are unlicensed for use in nodular Dermatology Nursing 2007. 19(3): 243 - 248 prurigo. However, this does not make them ineffective. References 15. Lim VM, Maranda EL, Patel V, Simmons BJ, Jimenez JJ. A review of the 1. Eigelshoven S, Homey B. Prurigo effi cacy of Thalidomide and Lenalidomide Systemic treatments include: Nodularis. CME Dermatology 2009, 4(3): in the treatment of refractory prurigo 8 Antihistamines. Generally, 140-155. Available at www.cme.akademos. nodularis. Dermatology Therapy 2016. sedating antihistamines are more de/derma. [Accessed November 2017] 6:397- 411

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