Reactive Granulomatous Dermatitis: A Descriptive Study of 10 Patients

Area of Science:

• Dermatology
• Rheumatology
• Oncology

Background:

• Reactive granulomatous dermatitis (RGD) is a rare skin disorder encompassing interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis.
• RGD is associated with autoimmune diseases, malignancy, and drug use.

Purpose of the Study:

• To identify and describe systemic associations with RGD at diagnosis and within one year.
• To investigate the relationship between RGD, autoimmune conditions, malignancies, and drug therapies.

Main Methods:

• Retrospective analysis of RGD cases confirmed by skin biopsy and clinicopathologic correlation.
• Evaluation of 10 patients diagnosed between 2000 and 2020.
• Data collection included systemic diseases, suspected drugs, clinical presentation, and treatments.

Main Results:

• Seven out of 10 RGD patients had pre-existing autoimmune diseases (3 inflammatory arthritis, 4 inflammatory bowel disease).
• Two patients with autoimmune disease had suspected associations with tumor necrosis factor (TNF) inhibitors.
• One patient with idiopathic RGD developed high-grade B-cell lymphoma six months post-diagnosis.

Conclusions:

• This study supports known systemic associations of RGD, including autoimmune diseases, malignancy, and TNF inhibitors.
• The majority of RGD cases presented with a concurrent systemic condition at the time of diagnosis.