Dapsone for Recalcitrant Eosinophilic Annular Erythema: A Case Report and Literature Review

Repurposing Historic Drugs for Neutrophil-Mediated Inflammation in Skin Disorders

Neutrophil-mediated inflammation is a key feature of immune-mediated chronic skin disorders, but the mechanistic understanding of neutrophil involvement in these conditions remains incomplete. Dapsone, colchicine, and tetracyclines are established drugs within the dermatologist's therapeutic armamentarium that are credited with potent anti-neutrophilic effects. Anti-neutrophilic drugs have established themselves as versatile agents in the treatment of a wide range of dermatological conditions. Some of these agents are approved for the management of specific dermatologic conditions, but most of their current uses are off-label and only supported by isolated reports or case series. Their anti-inflammatory and immunomodulatory properties make them particularly valuable in managing auto-immune bullous diseases, neutrophilic dermatoses, eosinophilic dermatoses, interface dermatitis, and granulomatous diseases that are the focus of this review. By inhibiting inflammatory pathways, reducing cytokine production, and modulating immune responses, they contribute significantly to the treatment and management of these complex skin conditions. Their use continues to evolve as our understanding of these diseases deepens, and they remain a cornerstone of dermatological therapy.

Dapsone Use in Dermatology

Dapsone, initially synthesized for textile dyeing, gained recognition in the 1930s for its antibacterial properties, leading to its utilization in dermatology for leprosy and dermatitis herpetiformis. Despite US Food and Drug Administration (FDA) approval for these conditions, dapsone's off-label uses have expanded, making it a valuable option in various dermatologic conditions. This review seeks to highlight the common uses of dapsone in its FDA indications and off-label indications. Diseases in which dapsone is considered first-line therapy or adjunctive therapy are reviewed, with highlights from the resources included. An overview of dapsone's pharmacokinetics, pharmacodynamics, indications, dosages, and safety profile are also reviewed. Dapsone's versatility and safety profile make it a cost-effective treatment option in dermatology, particularly for patients with limited access to specialized medications. Ongoing clinical trials are also described exploring dapsone's efficacy in novel dermatologic uses. Dapsone has been a valuable adjunctive therapy across various dermatologic conditions for years and evidence for its use continues to expand.

Hyperactivation of the JAK2/STAT5 Signaling Pathway and Evaluation of Baricitinib Treatment Among Patients With Eosinophilic Cellulitis

Importance

The pathogenesis of eosinophilic cellulitis (EC) is poorly understood, limiting available treatment options. The current treatment paradigm focuses on delayed type 2 hypersensitivity reaction to various triggers.

Objective

To gain further insight into the nature of EC inflammation and into the cellular signal transduction pathways that are activated in the context of EC.

Design, Setting, and Participants

This case series was conducted in Lyon, France, from January 2018 to December 2021. Analysis of archival skin biopsy samples from patients with EC and from healthy control participants was performed using histology, Janus kinase (JAK)-signal transducer and activator of transcription (STAT) immunohistochemistry, and gene profiling. Data analysis was conducted between January 2020 and January 2022.

Main Outcomes and Measures

Pruritus (visual analog score), percentage of body surface area with lesional skin, and RNA transcripts of inflammatory biomarkers from the skin (threshold cycle) were assessed in 1 index patient with refractory EC who received oral JAK1/JAK2 inhibitor baricitinib (4 mg/d).

Results

This study included samples from 14 patients with EC (7 men and 7 women) and 8 healthy control participants (4 men and 4 women). The mean (SD) age of patients was 52 (20) years. Marked type 2 inflammation (chemokines CCL17, CCL18, and CCL26 and interleukin 13) with preferential activation of the JAK1/JAK2-STAT5 pathways in EC lesions was observed. In the 1 index patient with refractory EC, complete clinical remission of skin lesions was observed after 1 month of treatment with baricitinib.

Conclusions and Relevance

These findings suggest that EC is a type 2 inflammatory disease with preferential activation of the JAK1/JAK2-STAT5 pathways. In addition, these results suggest the potential of treatment approaches targeting JAK1/JAK2 for patients with EC.

Annular urticarial lesions

Annular urticarial configurations are often associated with acute and chronic urticaria. Such lesions may be short-lived, migratory, transient, pruritic, and resolving with no residual evidence, making the diagnosis of urticaria an obvious one. Annular urticarial lesions can be the presenting signs of various cutaneous and systemic diseases. The differentiation of urticarial lesions may be made by considering the duration of an individual lesion longer than 24 hours, with burning and pain sensation in the lesions or lack of pruritus; skin marks such as postinflammatory pigmentation or purpura after resolution of the lesions; associated scaling or vehiculation in the lesions; systemic symptoms such as arthralgia, fever or fatigue; and several abnormal laboratory findings. The main differential diagnoses of annular urticarial lesions include urticarial vasculitis, autoinflammatory syndromes, hypersensitivity reactions, and connective tissue diseases.

Eosinophilic Annular Erythema: A New Entity of Eosinophilic Dermatosis

Eosinophilic annular erythema (EAE) is a rare dermatosis. Its relationship with Wells syndrome (WS) is debated. We report a case treated with hydroxychloroquine.

 A 31-year-old patient presented with a mildly pruritic rash that had been evolving by flares for two weeks. Clinical examination revealed inflammatory erythematous-annular plaques on the trunk and limbs. The blood count was normal. Skin histology showed an eosinophilic-rich inflammatory infiltrate. After local steroid treatment, the patient was treated with oral steroids with a momentary improvement. The course with new relapses is treated by synthetic antimalarial drugs with the complete disappearance of the lesions at a six-month follow-up.

Although some authors consider EAE to be a variant of WS, we believe that there are subtle differences that differentiate them despite their clinical similarity.

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.

Eosinophilic annular erythema

Eosinophilic annular erythema (EAE) is a rare eosinophilic dermatosis characterized by annular, erythematous papules and plaques commonly found on the trunk and the extremities. There is continued debate on whether EAE is a distinct entity or a clinical polymorphism of Well's syndrome, but it is generally considered a separate entity based on clinical and histopathological differences. We present a case of EAE and discuss the histopathological findings.

Mepolizumab Therapy for Recalcitrant Eosinophilic Annular Erythema in an Adult: A Case Report and Review of Treatment Options

Eosinophilic annular erythema (EAE) is a rare condition with a chronic relapsing and remitting course, characterized by the presence of annular or polycyclic erythematous and plaque lesions and prominent tissue eosinophilia on histopathology. There is an ongoing discussion on whether EAE is a subset of Wells syndrome (eosinophilic cellulitis) or a separate entity. To date, few cases of EAE have been reported in the literature; of these, about 40 cases were in adults and fewer than ten cases were in children. Given the rarity of this condition, there are no clear recommendations for its management. Systemic corticosteroids and antimalarials are the most commonly used medications used to treat EAE, but many cases have been reported in the literature that are resistant to treatment with these medications. Here, we present a 65-year-old female with EAE refractory to numerous systemic therapies (corticosteroids, hydroxychloroquine, dapsone, doxycycline, methotrexate) who showed a good response to mepolizumab, a humanized monoclonal antibody that blocks interleukin-5. To the best of our knowledge, this is the first reported case of mepolizumab therapy in a patient with EAE. We also review other treatment strategies that have been used to manage this condition to date. Targeting cytokines crucial for the functioning of eosinophils may be a novel direction in the management of EAE, but prospective, double-blinded and placebo-controlled studies are needed to provide further evidence.