The neglected twin: Nummular eczema is a variant of atopic dermatitis with codominant TH2/TH17 immune response.

BACKGROUND: Nummular eczema (NE) is a common chronic inflammatory skin disease characterized by multiple, pruritic, discoid-shaped lesions. Since the underlying immune mechanisms are not fully understood, it is unclear whether NE should be regarded as variant of atopic dermatitis (AD) or a distinct disease. OBJECTIVE: We compared the clinical, histopathologic, and molecular signatures of NE with that of type 2 and type 3 skin diseases. METHODS: We performed bulk RNA sequencing as well as histologic and clinical studies in lesional and nonlesional skin biopsy specimens from NE (n = 50), AD (n = 47), and psoriasis (n = 90) patients. RESULTS: NE displayed typical hallmarks of AD, such as an impaired epidermal barrier, microbial colonization, spongiosis, and eosinophil infiltration, but also aspects of psoriasis, including increased epidermal thickness, number of Ki-67+ cells, and neutrophilic infiltration. At the gene expression level, neutrophil-attracting cytokines (IL19, CXCL8, CXCL5) were upregulated, whereas TH2-related cytokines (IL13, CCL17, CCL18, CCL26, CCL27) were similarly expressed in NE compared to AD. Principal component analysis of transcriptome data from lesional skin showed that AD and NE cluster together distinct of psoriasis. In line with this, an established molecular classifier identified NE as AD rather than psoriasis. Finally, we demonstrated clinical and molecular efficacy of dupilumab treatment in NE. CONCLUSION: NE shows overlapping type 2 and type 3 immune signatures, while type 2 immunity predominates and should be the primary target of specific therapeutic interventions. This supports the view of NE as a variant of AD.

Prevalence and trend of allergen sensitization in patients with nummular (discoid) eczema referred for patch testing: North American Contact Dermatitis Group data, 2001-2016.

BACKGROUND: Few studies have examined the relationship between nummular (discoid) eczema (NE) and allergic contact dermatitis (ACD). OBJECTIVE: To examine trends, associations, and clinical relevance of ACD in patients with NE who were referred for patch testing. METHODS: Retrospective analysis of 38 723 patients from the North American Contact Dermatitis Group. RESULTS: Overall, 748 patients (1.9%) were diagnosed with NE; 23.9% had a concomitant diagnosis of ACD. The prevalence of NE fluctuated over time between 2001 and 2016, with no overall change in prevalence in diagnosed NE. In multivariable logistic regression models, NE increased steadily with age and was associated with male sex and Asian and other race/ethnicity, and inversely associated with a history of atopic dermatitis (AD) and hay fever. Patients with NE had lower proportions of one or more positive allergic reactions and lower odds of a positive reaction in multiple individual allergens. The most commonly relevant allergens in patients with NE were formaldehyde 2.0% aq., methylisothiazolinone, quaternium 15, fragrance mix I, and propylene glycol. CONCLUSION: NE is a heterogeneous disorder with distinct subsets of lesional distributions and a profile of relevant allergens, especially formaldehyde and formaldehyde releasers. Nearly one in four patients with NE had ACD, supporting the role of patch testing in patients with NE.

Effectiveness of dupilumab for the treatment of nummular eczema phenotype of atopic dermatitis in adults.

Nummular eczema (NE) is currently considered as one of the clinical phenotypes of atopic dermatitis (AD) of the adult. In this multicentre study, 30 adult patients (age ≥ 18 years) affected with nummular-like AD were treated with dupilumab, a monoclonal antibody against the receptor for interleukin(IL)-4 and IL-13. The evaluation of the results after 16 weeks of treatment showed a significant improvement of the disease, as demonstrated by reduction in Eczema Area Severity Score (EASI), visual analogue score (VAS) of pruritus, and Dermatology Life Quality Index (DLQI) scores. Conjunctivitis in one patient was the only side effect. In conclusion, dupilumab seems to be an effective and safe treatment in NE phenotype of AD of the adult.

Methotrexate for severe nummular eczema in children: Efficacy and tolerability in a retrospective study of 28 patients.

BACKGROUND/OBJECTIVES: Nummular eczema in children is a chronic condition characterized by pruritic coin-shaped eczematous lesions that affect any part of the body and often become exudative. Mid- to high-potency topical corticosteroids are considered the mainstay treatment, but there are limited data on the use of systemic therapy for nummular eczema in children. The objective of the current study was to evaluate the efficacy and safety of methotrexate in children with severe nummular eczema. METHODS: A retrospective review was undertaken of children with nummular eczema treated with methotrexate between January 2007 and May 2017. RESULTS: The records of 28 patients (24 male, 4 female) with a mean age at the beginning of treatment of 7.8 ± 1.6 years (95% confidence interval (CI) = 6.1-9.4 years) were reviewed. The median duration of treatment was 12.6 ± 3.3 months (95% CI = 9.2-16 months), and 14 patients were still undergoing methotrexate therapy at the time of last review. Ten patients (35.7%) had complete or almost complete clearance of eczema (> 90% improvement), 13 (46.4%) had marked improvement (50%-89%), four had mild improvement (< 50%), and one failed methotrexate therapy. Gastrointestinal intolerance (21.4%) and a nonsignificant increase in liver enzymes (17.9%) were the most frequent side effects. No serious adverse events were noted. CONCLUSION: Methotrexate is an effective, well-tolerated treatment in children with moderate to severe nummular eczema that has failed to respond to conventional topical therapy.

Porokeratosis of gluteal region: A case report.

Genitogluteal porokeratosis is a rare localized disorder of keratinization. Due to the rarity of the case and non-specific keratotic lesion, it is often misdiagnosed until a histological examination is performed. Treatment of this condition can be challenging, which comprises various topical and systemic drugs, lasers, cryotherapy, phototherapy, and also surgical intervention. Regular follow-up is necessary in the view of this disorder being a premalignant condition.

Nummular Eczema: An Updated Review.

BACKGROUND: Nummular eczema may mimic diseases that present with annular configuration and the differential diagnosis is broad. OBJECTIVE: This article aimed to provide an update on the evaluation, diagnosis, and treatment of nummular eczema. METHODS: A PubMed search was performed in using the key terms "nummular eczema", "discoid eczema", OR "nummular dermatitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article. Patents were searched using the key terms "nummular eczema", "discoid eczema", OR "nummular dermatitis" in www.google.com/patents and www.freepatentsonline.com. RESULTS: Nummular eczema is characterized by sharply defined, oval or coin-shaped, erythematous, eczematous plaques. Typically, the size of the lesion varies from 1 to 10cm in diameter. The lesions are usually multiple and symmetrically distributed. Sites of predilection include the lower limbs followed by the upper limbs. The lesions are usually intensely pruritic. The diagnosis is mainly clinical based on the characteristic round to oval erythematous plaques in a patient with diffusely dry skin. Nummular eczema should be distinguished from other annular lesions. Dermoscopy can reveal additional features that can be valuable for correct diagnosis. Biopsy or laboratory tests are generally not necessary. However, a potassium hydroxide wet-mount examination of skin scrapings should be performed if tinea corporis is suspected. Because contact allergy is common with nummular eczema, patch testing should be considered in patients with chronic, recalcitrant nummular eczema. Avoidance of precipitating factors, optimal skin care, and high or ultra-high potency topical corticosteroids are the mainstay of therapy. Recent patents related to the management of nummular eczema are also discussed. CONCLUSION: With proper treatment, nummular eczema can be cleared over a few weeks, although the course can be chronic and characterized by relapses and remissions. Moisturizing of the skin and avoidance of identifiable exacerbating factors, such as hot water baths and harsh soaps may reduce the frequency of recurrence. Diseases that present with annular lesions may mimic nummular eczema and the differential diagnosis is broad. As such, physicians must be familiar with this condition so that an accurate diagnosis can be made, and appropriate treatment initiated.

Diagnostic usefulness of dermoscopy in differentiating lichen aureus from nummular eczema.

Lichen aureus (LA) is a variant of pigmented purpuric dermatosis that is characterized clinically by rust macules, papules or plaques, mainly on the legs. In some cases, LA can be difficult to be distinguished from nummular eczema (NE) with the naked eye. Dermoscopy can be applied to skin lesions, revealing additional features that can be highly valuable for correct diagnosis. This study was conducted to investigate characteristic dermoscopic findings of LA and to identify distinctive features that can differentiate it from NE. Fourteen LA patients and 14 NE patients diagnosed by skin biopsy were enrolled. Skin lesions were evaluated via polarized dermoscopy. On dermoscopy, "coppery orange diffuse coloration of background", "round to oval red globules", "gray dots", and "networks of brownish to gray interconnected lines" were more commonly seen in LA (100%, 92.9%, 42.9% and 64.3%, respectively) compared with NE. "Scales", "shiny yellow clods" and "irregularly distributed brownish-red globules" were more commonly seen in NE (100%, 85.7% and 57.1%, respectively) compared with LA. Dermoscopy provides valuable information for diagnosis of LA and aids in differentiating it from NE.

[Nummular dermatitis: report of two cases in children]. / Dermatitis numular: presentación de dos casos pediátricos.

Nummular eczema or dermatitis is an uncommon paediatric pathology. It is presented as red-purplish small papules and vesicles that join to form exudative circular patches and then to eczematous or lichenified patches with discoid shape. The lesions appear predominantly on the extensor surface of extremities, although they can appear in trunk, hands or feet. This pathology has a clinical diagnosis; only few cases require complementary test. The topical corticosteroids are the mainstay of the treatment, and the causal treatment whether an infectious trigger is found. The patients have chronic or recurrent evolution. We report two cases in children with the aim of spreading knowledge among pediatricians.

La dermatitis o eccema numular es una patología poco frecuente en pediatría. El cuadro se caracteriza por un inicio con diminutas pápulas y vesículas eritematovioláceas que confluyen en placas exudativas de forma circular y evolucionan a placas eccematosas o liquenificadas de forma discoide o anular. Aparecen, predominantemente, en superficies extensoras de las extremidades, aunque pueden encontrarse en el tronco, las manos o los pies. El diagnóstico es clínico; solo en casos con mala evolución pueden ser necesarias pruebas complementarias. La base del tratamiento son los corticoides tópicos y, si se encuentra un desencadenante infeccioso, el tratamiento de la causa. Su evolución suele ser crónica o recidivante. Se presentan dos casos clínicos en población pediátrica con la finalidad de difundir entre los pediatras su conocimiento y manejo.

Dermatitis numular: presentación de dos casos pediátricos / Nummular dermatitis: report of two cases in children

La dermatitis o eccema numular es una patología poco frecuente en pediatría. El cuadro se caracteriza por un inicio con diminutas pápulas y vesículas eritematovioláceas que confluyen en placas exudativas de forma circular y evolucionan a placas eccematosas o liquenificadas de forma discoide o anular. Aparecen, predominantemente, en superficies extensoras de las extremidades, aunque pueden encontrarse en el tronco, las manos o los pies. El diagnóstico es clínico; solo en casos con mala evolución pueden ser necesarias pruebas complementarias. La base del tratamiento son los corticoides tópicos y, si se encuentra un desencadenante infeccioso, el tratamiento de la causa. Su evolución suele ser crónica o recidivante. Se presentan dos casos clínicos en población pediátrica con la finalidad de difundir entre los pediatras su conocimiento y manejo.

Nummular eczema or dermatitis is an uncommon paediatric pathology. It is presented as red-purplish small papules and vesicles that join to form exudative circular patches and then to eczematous or lichenified patches with discoid shape. The lesions appear predominantly on the extensor surface of extremities, although they can appear in trunk, hands or feet. This pathology has a clinical diagnosis; only few cases require complementary test. The topical corticosteroids are the mainstay of the treatment, and the causal treatment whether an infectious trigger is found. The patients have chronic or recurrent evolution. We report two cases in children with the aim of spreading knowledge among pediatricians.