Reactive granulomatous dermatitis as a clinically relevant and unifying term: a retrospective review of clinical features, associated systemic diseases, histopathology and treatment for a series of 65 patients at Mayo Clinic

Surgical Excision of Palisaded Neutrophilic and Granulomatous Dermatitis of the Vulva: A Case Report

Palisaded neutrophilic and granulomatous dermatitis (PNGD) is an inflammatory cutaneous disorder of unknown etiology that typically occurs in association with systemic disease. Rheumatoid arthritis and systemic lupus erythematosus are the most common associated diseases. PNGD manifests as skin-colored to erythematous papules and plaques, mainly on the extremities. However, to the best of our knowledge, no cases of PNGD in the vulva have been reported in foreign literature to date. Herein, we report the first case of a 31-year-old female with systemic lupus erythematosus disease who presented multiple plaques and a pigmented, rough, mamillated skin surface affecting the vulva, leading to disfigurement of the vulva and interfering with sexual intercourse due to severe pain, irritation, and frequent infection. Surgical excision of the whole lesion with reconstruction of the vulva was done in two sessions and histologically diagnosed as PNGD.

Eosinophilic Dermatosis of Hematologic Malignancy: Emerging Evidence for the Role of Insect Bites-A Retrospective Clinico-Pathological Study of 35 Cases

Background/Objectives: Eosinophilic dermatosis of hematologic malignancy (EDHM) is a rare cutaneous disorder associated with various hematologic malignancies, most commonly chronic lymphocytic leukemia. Detailed clinicopathologic studies of EDHM are lacking and the pathogenesis remains enigmatic. Initially thought to be a hypersensitivity reaction to insect stings, subsequent reports have challenged this understanding. The prognostic implications of EDHM remain unclear. Methods: A retrospective clinicopathologic study was performed on patients diagnosed with EDHM. Hematologic and dermatologic data were reviewed. Histologic specimens were re-evaluated and lesions were classified into acute/subacute, fully developed, and chronic/regressing. Results: The study included 35 patients. In 80% of these patients, EDHM was diagnosed after the hematologic disorder. Approximately 45% of the cohort experienced hematologic disease progression or relapse, while 65% required therapeutic intervention during the course of their hematologic disease. In total, 15/19 CLL patients had non-mutated IgHV, a marker of a more aggressive hematologic disease course. Dermatologic lesion morphology was heterogeneous, with most lesions occurring on exposed areas, and a significant 94% of patients demonstrated lesion seasonality. Histopathologic findings were consistent with features typically associated with insect bites. In addition, examination of lesions at different chronological stages revealed substantial similarities with Wells syndrome. Conclusions: Our findings support the potential role of insect bites in triggering EDHM in the context of adaptive immune dysfunction. EDHM may be associated with a more aggressive disease course or may be a marker of disease progression. The observed co-occurrence of features typical of Wells syndrome in EDHM patients suggests that these conditions are part of a spectrum of disorders that vary in clinical expression.

Palisaded Neutrophilic Granulomatous Dermatitis, Bowel-Associated Dermatosis-Arthritis Syndrome, and Rheumatoid Neutrophilic Dermatitis

Neutrophilic dermatosis is a heterogeneous group of inflammatory skin diseases characterized by the presence of a sterile neutrophilic infiltrate on histopathology. Three specific types of neutrophilic dermatoses are reviewed in this article: palisaded neutrophilic granulomatous dermatitis, bowel-associated dermatosis-arthritis syndrome, and rheumatoid neutrophilic dermatitis. The authors review the literature and highlight the clinical and histopathological features, disease pathogenesis, and the association of these conditions with various systemic diseases such as rheumatoid arthritis, inflammatory bowel disease, and others. A multidisciplinary approach is necessary for the diagnosis and management of these inflammatory skin conditions.

Reactive Granulomatous Dermatitis: A Descriptive Study of 10 Patients

BACKGROUND

Reactive granulomatous dermatitis (RGD) is a rare and misunderstood skin disorder. It includes interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis: 2 entities of the same spectrum. Multiple associations are described with RGD in the literature, including autoimmune diseases, malignancy, and drugs.

OBJECTIVE

To report and describe the suspected associations with RGD at the time of diagnosis and in the following year.

METHODS

We retrieved and described cases of RGD confirmed by skin biopsy and clinicopathologic correlation. All patients were evaluated in the Centre Hospitalier Universitaire de Québec-Université Laval between January 2000 and December 2020. Collected data include the systemic diseases (autoimmune disease, malignancy) and suspected drugs, in addition to the clinical presentation and prescribed treatments.

RESULTS

Out of the 10 patients with RGD, 7 patients were known to have an autoimmune disease at the time of diagnosis. They either had inflammatory arthritis (3/10) or inflammatory bowel disease (4/10). There was a clinical suspicion of a possible association with a tumor necrosis factor (TNF) inhibitor in 2 of these 7 patients. Among the 3 patients with idiopathic RGD at the time of diagnosis, 1 patient developed a high-grade B-cell lymphoma 6 months later. There was no new association identified in the following year for patients with a known autoimmune condition.

CONCLUSION

This descriptive study supports RGD and its previously described systemic associations, particularly autoimmune diseases, malignancy, and certain drugs (specifically TNF inhibitors). The majority of patients already had one of these associations identified at the time of histopathological diagnosis.

Interstitial Granulomatous Dermatitis and Palisaded Neutrophilic Granulomatous Dermatitis: Retrospective Clinicopathological Analysis of 16 Cases

INTRODUCTION

Reactive granulomatous dermatitis (RGD) is a new entity, which is highly associated with systemic disorders. There is scarce data regarding interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic granulomatous dermatitis (PNGD).

OBJECTIVES

We aimed to evaluate clinical and histopathological characteristics of IGD and PNGD as unified entities under the term of RGD.

METHODS

Observational, retrospective, single-center study of patients diagnosed with IGD and PNGD between 2012 and 2021 were included in the study.

RESULTS

Of 16 patients (14 females and 2 males) with RGD, 13 had IGD and 3 had PNGD with a mean age of 62.5 years. The most common clinical presentation was plaques 37.5% (N=6), followed by patches 25% (N=4). The most common localization of involvement was lower extremity 75% (N=12), followed by trunk and upper extremity. Multiple localization of involvement was determined in 75% (N=12) of patients. None of the patients had rope sign. Associated comorbidities such as autoimmune diseases and malignancies were detected in 68.7% (N=11) of patients. In majority of biopsies (87.5%; N=14), there were lymphohistiocytic cell infiltration. Other accompanying cells were scarce neutrophils 31.2% (N=5) and eosinophils 31.2% (N=5). All of the biopsies had interstitially located lymphohistiocytic cell infiltration surrounding with swollen and degenerated collagen. Palisaded pattern was determined in 18.7% (N=3) of patients and floating sign was seen in 18.7% (N=3) of biopsies.

CONCLUSIONS

RGD is a rare entity and most patients with RGD had associated disorders such as autoimmunity or malignancy. There is overlapping between IGD and PNGD, therefore supporting the usage of umbrella term as reactive granulomatous dermatitis is compatible with the literature.