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

Abstract

Background Reactive granulomatous dermatitis (RGD) is an umbrella term used to describe interstitial granulomatous dermatitis (IGD), palisaded neutrophilic and granulomatous dermatitis (PNGD), and interstitial granulomatous drug eruption (IGDR). Objective The aim of this study was to describe systemic associations of RGD, explore possible associations between histopathologic findings and systemic RGD associations and determine clinical relevance of RGD subtypes. Methods We retrospectively studied clinical and histopathologic characteristics of patients with RGD from 1990 through 2020. Results Of 65 patients with RGD (41 women, 24 men; median age at diagnosis, 62 years), 37 had IGD, 26 had PNGD, and 2 had IGDR. Fifty patients (76.9%) had an associated systemic condition; rheumatologic conditions were identified for 34 (52.3%) patients. The associated systemic condition occurred before RGD in approximately 75% of patients. Statistical analyses did not show significant associations between specific subtypes of RGD and systemic diseases or treatment response, and specific histopathologic findings were not predictive of an associated systemic disease. Conclusions Although most patients with RGD had an associated systemic condition, subtypes of RGD did not correlate with systemic associations, lending support to the use of the umbrella term RGD.

Reactive Granulomatous Dermatitis: A Descriptive Study of 10 Patients

“…The association with hematological neoplasms has also been noted in the literature, such as Hodgkin lymphomas, myelodysplastic syndromes, and acute myelocytic leukemia. 1,2,4,15 In most cases, skin involvement did not resolve within the year following the diagnosis of RGD. These findings contrast with previous studies where PNGD patients had rapid resolution and IGD patients had spontaneous remission.…”

“…In this same study, the most common association was a rheumatologic condition (52.3% of patients). 2 Besides arthritis and inflammatory bowel disease, systemic lupus erythematosus, systemic sclerosis, ANCA vasculitis, Sjogren's syndrome, and mixed cryoglobulinemia have also been described with RGD. [1][2][3][8][9][10][11][12][13] Analogous to previous publications, TNF inhibitors could be a trigger for RGD.…”

“…Other drugs often associated with RGD are calcium channel blockers, angiotensin-converting enzyme inhibitors, statins, furosemide, and beta-blockers. 1,2,5 No patient had malignancy at the time of diagnosis, but 1 patient was diagnosed with a high-grade B-cell lymphoma in the following months. The association with hematological neoplasms has also been noted in the literature, such as Hodgkin lymphomas, myelodysplastic syndromes, and acute myelocytic leukemia.…”

“…2 Besides arthritis and inflammatory bowel disease, systemic lupus erythematosus, systemic sclerosis, ANCA vasculitis, Sjogren's syndrome, and mixed cryoglobulinemia have also been described with RGD. [1][2][3][8][9][10][11][12][13] Analogous to previous publications, TNF inhibitors could be a trigger for RGD. 14 Out of the 10 patients in our study, 2 cases were possibly related to this medication.…”

Reactive granulomatous dermatitis: Lumping terms to split confusion

“…In this issue of JEADV , Kumar et al 4 . provide additional support for the concept of RGD as an encompassing term for this family of diseases.…”