Neutrophilic dermatoses.

Neutrophilic dermatoses (ND) are a group of inflammatory skin conditions characterized by a neutrophilic infiltrate on histopathology with no evidence of infection. ND are classified based upon the localization of neutrophils within the skin and clinical features. Recent findings suggest that ND are due to two main mechanisms: i) a polyclonal hereditary activation of the innate immune system (polygenic or monogenic); or ii) a clonal somatic activation of myeloid cells such as encountered in myelodysplastic syndrome or VEXAS syndrome. ND belong to internal medicine as a great number of patients with ND suffer from an underlying condition (such as hematological malignancy, inflammatory bowel disease, auto-immune and auto-inflammatory diseases). ND are diagnoses of exclusion and physicians should always consider differential diagnoses, particularly skin infections. Here, we review the pathophysiology and classification of the main ND (i.e., subcorneal pustular dermatosis (Sneddon-Wilkinson Disease) and Intercellular IgA dermatoses, aseptic pustulosis of the folds, Sweet syndrome, neutrophilic eccrine hidradenitis, pyoderma gangrenosum, erythema elevatum diutinum, neutrophilic urticarial dermatosis and neutrophilic panniculitis), their clinical and histopathological features, and we highlight the investigations that are useful to identify ND-associated diseases and to exclude the differential diagnoses.

[Dupilumab-related blepharoconjunctivitis: Recommendations of the CEDRE group. Atopic dermatitis, conjunctivitis and dupilumab: Which management approach?] / Blépharo-conjonctivites sous dupilumab : recommandations du groupe CEDRE. Dermatite atopique, conjonctivites et dupilumab : quelle prise en charge ?

Dupilumab is a recombinant monoclonal IgG4 type antibody which inhibits IL4 and IL13 signaling. It is indicated in moderate to severe atopic dermatitis (AD) in adults and adolescents over 12 years of age. Its side effects include conjunctivitis and blepharoconjunctivitis, affecting between 4.7% and 28% of patients depending on the study. The incidence of conjunctivitis in patients treated with dupilumab for AD appears to be higher than placebo in clinical studies. This increase was not observed in patients treated with dupilumab for asthma or sinonasal polyposis. The risk factors for conjunctivitis in patients with AD are disease severity, pre-existence of conjunctivitis and low concentrations of dupilumab, but the pathophysiology of this disease is poorly understood. A literature search carried out in April and May 2020 showed an increase in the number of publications on the subject, but there are currently no official joint dermatologist-ophthalmologist recommendations for prevention and management. The objective of this article is to provide an overview of the status of this subject, to address the main questions raised by this type of conjunctivitis and to suggest a course of action for starting and continuing treatment with dupilumab in patients with AD, according to the recommendations of the French Ophthalmologist/Dermatologist group CEDRE.

Treatment of Eosinophilic Annular Erythema: Retrospective multicenter study and literature review.

BACKGROUND: Eosinophilic annular erythema (EAE) is a rare eosinophil-related skin disease which typically manifests with annular erythematous plaques and severe pruritus. Besides the diagnosis, the treatment of EAE is challenging since relevant published data are sparse. METHODS: The aim of this study was to assess the underlying diseases, treatments and outcomes of patients with EAE. To this end, we conducted a retrospective multicenter study and a systematic review of the MEDLINE database. RESULTS: We included 18 patients with EAE followed in 8 centers. The MEDLINE database search yielded 37 relevant publications reporting 55 cases of EAE with 106 treatment sequences. The most common and efficient treatments included topical or systemic corticosteroids, hydroxychloroquine and dapsone. In refractory patients, a combination of systemic corticosteroids with hydroxychloroquine was associated with 88% of complete clinical response. DISCUSSION: To improve the management of EAE patients, we discuss the following treatment strategy: in topical steroid-resistant patients, hydroxychloroquine can be given as first-line systemic treatment. Dapsone, hydroxychloroquine or systemic corticosteroids are second-line options to consider. Last, monoclonal antibodies or JAK inhibitors targeting type 2 inflammation could represent promising last-resort options in refractory patients.

[Association of borderline tuberculoid leprosy and tuberculosis: A case report and review of the literature]. / Association d'une lèpre borderline tuberculoïde et d'une tuberculose : un cas et revue de la littérature.

INTRODUCTION: In metropolitan France, nearly 20 new cases of leprosy are diagnosed each year. The incidence of tuberculosis in France is 8/100,000 inhabitants and there are very few accounts of association of these two mycobacteria. Herein we report a case of co-infection with borderline tuberculoid (BT) leprosy and disseminated tuberculosis diagnosed in metropolitan France. PATIENTS AND METHODS: A male subject presented with diffuse painless infiltrated erythematous plaques. The biopsy revealed perisudoral and perineural lymphohistiocytic epithelioid cell granuloma as well as acid-alcohol-fast bacilli on Ziehl staining. PCR was positive for Mycobacterium leprae, confirming the diagnosis of leprosy in the BT form. The staging examination revealed predominantly lymphocytic left pleural effusion, right-central necrotic adenopathy without histological granuloma, negative screening for BK, a positive QuantiFERON-TB™ test, and a positive intradermal tuberculin reaction. The clinical and radiological results militated in favour of disseminated tuberculosis. Combined therapy (rifampicin, isoniazid, ethambutol and pyrazinamide) together with clofazimine resulted in regression of both cutaneous and extra-cutaneous lesions. This rare co-infection combines leprosy, often present for several years, and tuberculosis (usually pulmonary) of subsequent onset. The pathophysiological hypothesis is that of cross-immunity (with anti-TB immunity protecting against subsequent leprosy and vice versa), supported by the inverse correlation of the two levels of prevalence and by the protection afforded by tuberculosis vaccination. In most cases, treatment for TB and leprosy improves both diseases. Patients presenting leprosy should be screened for latent tuberculosis in order to avoid reactivation, particularly in cases where corticosteroid treatment is being given.

[Cutaneous plasmacytosis with Darier's sign in a woman of European origin]. / Plasmocytose cutanée avec signe de Darier chez une femme d'ascendance européenne.

INTRODUCTION: Cutaneous plasmacytosis is a rare skin condition first described in 1976 and it is seen mainly in patients of Asian descent. Patients usually present with multiple reddish-brown macules and nodules chiefly on the trunk and face, with clusters of well-differentiated plasma cells in the dermis. The aetiopathogenesis and nosological features of this entity remain obscure. We report herein a case of cutaneous plasmacytosis in a European middle-aged woman with presence of Darier's sign. PATIENTS AND METHODS: A 56-year-old woman of European descent presented with asymptomatic hyperpigmented patches affecting the dorsal aspect of her trunk for at least two years. Darier's sign was present in some episodes. Cutaneous biopsy showed a moderately dense interstitial and perivascular infiltrate containing numerous well-differentiated mature plasma cells affecting the entire dermal surface. Kappa and lambda immunochemistry demonstrated polyclonal plasma cell infiltrates with absence of light-chain restriction. Immunohistochemical examination was negative for HHV-8 and Treponema pallidum spirochetes. Laboratory findings revealed hypergammaglobulinaemia with no monoclonal bands being detected on immunofixation. A diagnosis of cutaneous plasmacytosis was made. In the absence of systemic involvement initial management consisted of clinical surveillance. DISCUSSION: The characteristic clinico-pathological features of CP allowed diagnosis of this skin condition in our patient, although it is very rarely reported in patients of European descent. The main differential diagnoses were ruled out, namely plasmacytic infiltrates related to infections and marginal B-cell lymphoma.