Prurigo Nodularis: George Cohen, MD Department of Dermatology & Cutaneous Picking the Right Treatment Surgery, University of South Florida, Tampa (Dr
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Michael Saco, MD; Prurigo nodularis: George Cohen, MD Department of Dermatology & Cutaneous Picking the right treatment Surgery, University of South Florida, Tampa (Dr. Saco); Department of Dermatology, University Most patients with localized nodules should receive of Florida, Gainesville topical treatment first. But disappointing results or (Dr. Cohen) specific findings described here could necessitate [email protected] The authors reported no additional or alternative options. potential conflict of interest relevant to this article. CASE u A 43-year-old woman arrives at your office with persis- Practice tent itching on her arms and legs. for some time, she has used recommendatIonS moisturizing lotions and herbal preparations suggested by her › Start with topical cortico- mother, but they have provided no relief. you note multiple 0.5- steroids under occlusion and to 2-cm firm, excoriated nodules symmetrically distributed on her periodically substitute with elbows and knees bilaterally. She has seasonal allergies and a his- steroid-sparing agents tory of childhood asthma. how would you care for this patient? (calcipotriol ointment or pimecrolimus 1% cream) reating prurigo nodularis (PN) can be a daunting task for localized for even the most experienced clinician. Prurigo nod- prurigo nodularis. B ules are cutaneous lesions often produced by repetitive › Consider adding oral T scratching—hence the nickname “picker’s nodules”—which antihistamines or may occur as sequelae of chronic pruritus or neurotic exco- montelukast to the initial riations. Thus, PN can be classified as a subtype of neuroder- regimen if a pruritic cause is suspected; alternatively, matitis. The nodules can be intensely pruritic, resulting in an 1,2 consider adding these agents itch-scratch cycle that can be difficult to break. In this review, if topical therapies alone we examine evidence-based therapies for PN. do not effectively treat the prurigo nodules. C › Turn to oral naltrexone, Key findings with prurigo nodularis gabapentin, or pregabalin Typically, prurigo nodules are firm, hyperkeratotic, pruritic for more widespread or papules or nodules that range in diameter from a few milli- treatment-resistant cases. C meters to several centimeters. The lesions usually have eroded or ulcerated components secondary to repeated excoriation, Strength of recommendation (SoR) which can eventually lead to scarring and changes in pigmen- A Good-quality patient-oriented evidence tation. Patients can have one nodule or hundreds of lesions, B Inconsistent or limited-quality depending on disease severity. The lesions tend to be distrib- patient-oriented evidence uted symmetrically and have a predilection for the extensor C Consensus, usual practice, opinion, disease-oriented surfaces of the upper and lower limbs. The abdomen, posterior evidence, case series neck, upper and lower back, and buttocks are also commonly affected, whereas the face, palms, and flexural areas are rarely involved2-5 (FIGURE 1). The differential diagnosis for PN includes dermatitis herpetiformis, scabies, lichen simplex chronicus, hypertro- jfponline.com Vol 64, no 4 | ApRIL 2015 | The jouRnAl of Family PracTice 221 phic lichen planus, perforating disorders, development and perpetuation of the nod- atopic dermatitis, allergic contact derma- ules. In cases associated with an underlying titis, neurotic excoriations, and multiple psychiatric component, such as delusional keratoacanthomas.4,5 parasitosis, patients often lack insight into PN prevalence and etiology are un- their condition and thus may benefit from known. Although PN can occur at any age, treatment of psychiatric comorbidities.4,7 the typical age range is 20 to 60 years, with z on physical exam, try to find lesions middle-aged women most commonly affect- that have not been traumatized by patients. ed. Patients who develop PN at a younger age They can be useful in uncovering a primary are more likely to have an atopic diathesis.3,4 cause, such as scabies, atopic dermatitis, li- There is ongoing debate regarding chenoid drug eruption, or simple xerosis. whether PN is a primary cutaneous disease or If a diagnosis cannot be made clinically, a response to repetitive scratching provoked consider obtaining a biopsy of a nontrauma- by a separate cause. PN has been associated tized lesion. Traumatized lesions are typically with a variety of diseases, such as psychiat- unrevealing on histopathology. If the clinical ric disorders, atopic dermatitis, chronic re- assessment of pruritic lesions is indeterminate, nal failure, hyperthyroidism, iron-deficiency laboratory tests that may prove helpful include, anemia, obstructive biliary disease, gastric but are not limited to, thyroid-stimulating hor- malignancy, lymphoma, leukemia, human mone levels, liver function tests, kidney func- Consider immunodeficiency virus (HIV), hepatitis B, tion, a hepatitis panel, and HIV screening. obtaining a and hepatitis C.2,3 With severe refractory pruritus in which a biopsy of a primary cutaneous or systemic cause cannot non-traumatized be determined, evaluate for malignancy—es- lesion, which Use the diagnostic work-up pecially polycythemia, lymphoma, or multi- can help uncover to focus management decisions ple myeloma—by ordering liver function tests scabies, atopic When taking the history, first determine why (including lactate dehydrogenase), a com- dermatitis, patients are picking or scratching. If the le- plete blood count with differential, a basic lichenoid drug sions are pruritic or painful, look for a poten- metabolic panel, a chest x-ray, and possibly a eruption, or tial underlying cause of pruritic symptoms.6 serum protein electrophoresis.7 simple xerosis. If you identify an underlying dermatologic or systemic condition, treat that disorder first.1 For example, adequately treating a patient’s Available treatments atopic dermatitis or hyperthyroidism may If the patient’s pruritic symptoms do not re- quell the pruritic symptoms and potentially solve and an underlying cause cannot be make the prurigo nodules more responsive determined, direct treatment at decreasing to symptomatic treatment or even obviate the pruritus either locally or systemically. Topi- need for such measures. cal therapies, typically associated with fewer If treating the underlying cause of PN adverse effects, are preferable in localized does not provide adequate relief, or if no cases of PN. In more severe, widespread, or cause for pruritic nodules can be found, the recalcitrant disease, systemic agents may be nodules may yet respond to symptomatic necessary. Typical first-line treatments for treatments targeted at decreasing pruritus PN aimed at decreasing pruritic symptoms and inflammation. In contrast, with patients include: who habitually scratch lesions they describe • topical antipruritics, such as ointments as non-pruritic, neurotic excoriations could containing menthol or camphor; topi- be the source of PN, making the nodules less cal corticosteroids, with increased ef- likely to respond to antipruritic therapies.4,7 ficacy under occlusion as seen with z Patient insights. Assessing whether flurandrenolide tape (Cordran tape) patients have insight into their condition is • oral antihistamines, such as prometha- also important. Some patients may be un- zine hydrochloride; oral antidepres- aware that they are repetitively picking and sants, such as doxepin scratching the affected areas and causing the • intralesional corticosteroids—eg, 222 The jouRnAl of Family PracTice | ApRIL 2015 | Vol 64, no 4 prurigo nodulAris triamcinolone acetonide (the con- figure 1 centration used depends on the Classic distribution of prurigo nodules thickness of the lesion and how well the lesion responded to prior injections) • a short course of systemic cortico- steroids, unless the patient has a comorbid condition that could be ex- acerbated by rapid tapering of cortico- steroids (eg, psoriasis). For patients with concomitant depres- p sion or anxiety, treatment with a selective ho T o S serotonin reuptake inhibitor or anxiolytic, cou 2-4 respectively, may be indicated. With the rt e 8,9 S exception of topical corticosteroids and y of: Geo oral antihistamines,10 the aforementioned first-line treatments for PN are mostly based rg e on clinical experience and anecdotal success c ohen, with no studies to support their use.3 Further- tK m more, these treatments may be ineffective D 11,12 for many patients. We present our review This patient has markedly ulcerated lesions on his upper back, lower back, and of several studies in the literature examining extensor surfaces of both arms. The face and palms are rarely involved. potential therapies for PN. topical therapies matitis.14 Their antipruritic effect, likely re- Calcipotriol vs betamethasone. A prospec- lated to their influence on cutaneous sensory tive, randomized, double-blind study that nerve fibers and inhibition of inflammatory ran right/left comparisons of calcipotriol cytokines, could also explain their efficacy in 15,16 ointment (a vitamin D3 analog) and beta- treating PN. methasone ointment as treatment for PN in A randomized, hydrocortisone-controlled, 9 patients showed that calcipotriol and be- double-blind phase II trial sponsored by No- tamethasone were both effective. However, vartis was designed as a right/left comparison calcipotriol ointment 50 mcg/g was more study between pimecrolimus 1% cream and effective in reducing the number and size of hydrocortisone 1% cream in 30 patients with nodules compared with 0.1% betamethasone