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.