A child with interstitial granulomatous dermatitis and juvenile idiopathic arthritis

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

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 as a histological pattern including manifestations of interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis: a study of 52 patients

BACKGROUND

Confusion exists regarding interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic and granulomatous dermatitis (PNGD).

OBJECTIVE

To determine whether IGD and PNGD are two different entities, or whether they must be considered as two subtypes of the same reactive pattern, and thus whether the unification of the nomenclature is necessary.

METHODS

Observational retrospective multicentre study of patients with IGD and PNGD evaluated between 1999 and 2019 and review of their clinical and histological features.

RESULTS

We identified 52 patients (38 women and 14 men). Clinical and histological findings of IGD were observed in 88.4% of cases. The most common cutaneous lesions were plaques/macules (IGD) or annular plaques and papules/nodules (PNGD), located mostly on the limbs and trunk. The rope sign was developed in two patients with IGD that associated autoimmune disorders. Similar associated comorbidities (75%) were found in both entities, mainly autoimmune diseases (53.8%). In IGD, the infiltrate was predominantly lympho-histiocytic. Neutrophilic infiltrates, karyorrhexis and skin lesions with limited clinical course were mainly associated with PNGD biopsies. In biopsies with a limited recurrent course, a predominant lymphocytic inflammatory infiltrate was found. Collagen degeneration was present in 75.9% of cases. The floating sign was observed only in IGD type patients (63%). Overlapping histological findings were found in one fourth of cases, especially between IGD and interstitial granuloma annulare. Interface dermatitis, apparently unrelated to drug intake, was observed in 4 cases of IGD.

CONCLUSION

We support the term reactive granulomatous dermatitis to unify both the clinical and histological findings of IGD and PNGD, and the overlapping between IGD and interstitial granuloma annulare. According to this, a spectrum of histological changes will be found depending on the clinical course of the skin lesions.

Clinical and histologic presentation of pediatric reactive granulomatous dermatitis

OBJECTIVE

To characterize the clinical and histologic presentation of reactive granulomatous dermatitis (RGD) in the pediatric population.

METHODS

In this multicenter retrospective chart review, 7 pediatric patients with biopsy-proven RGD were identified. Photographs, histology reports, and clinical course were reviewed to discover patterns in demographics, comorbid conditions, autoimmune sequelae, drug exposures, infections, morphology, and histologic features.

RESULTS

Overall, 7 patients were included and analyzed. Most were female and Hispanic. All presented with a similar dermatologic phenotype previously described in the adult literature including macular erythema and annular, pink to violaceous, edematous papules and plaques, often involving proximal extremities and extensor joints. All biopsies demonstrated variable collagen alteration and a perivascular interstitial infiltrate of histiocytes with or without mucin. Neutrophils or karyorrhexic debris were present in 4/7 of the biopsies, and eosinophils were occasionally seen (2/7 cases). In all cases, RGD was associated with active SLE or led to a new diagnosis, and initiation of systemic treatment improved cutaneous disease.

CONCLUSIONS

Pediatric RGD was more common in female patients and ethnic minorities, and strongly associated with SLE. Clinical and histologic presentations were consistent across all cases with only minor variations, suggesting that recognition and confirmation might be expedited by familiarity with these dominant patterns. Diagnosis of RGD in pediatric patients should prompt screening for SLE.

Granulomatous diseases: Kids are not just little people

Granulomatous diseases represent a heterogeneous group of conditions characterized by histiocytic inflammation that affect patients of any age. These diseases differ widely in their pathogenesis and include infectious and noninfectious conditions. This review focuses on noninfectious granulomatous conditions, with particular emphasis on age-related differences in the onset, epidemiology, clinical manifestations, prognosis, and age-specific management of specific granulomatous disorders. Knowledge of age-specific aspects of granulomatous conditions in adults and children improves both the extent of the diagnostic workup and the management of these patients.

Reactive Granulomatous Dermatitis: A Review of Palisaded Neutrophilic and Granulomatous Dermatitis, Interstitial Granulomatous Dermatitis, Interstitial Granulomatous Drug Reaction, and a Proposed Reclassification

The terms "palisaded neutrophilic and granulomatous dermatitis," "interstitial granulomatous dermatitis," and the subset "interstitial granulomatous drug reaction" are a source of confusion. There exists substantial overlap among the entities with few strict distinguishing features. We review the literature and highlight areas of distinction and overlap, and propose a streamlined diagnostic workup for patients presenting with this cutaneous reaction pattern. Because the systemic disease associations and requisite workup are similar, and the etiopathogenesis is poorly understood but likely similar among these entities, we propose the simplified unifying term "reactive granulomatous dermatitis" to encompass these entities.