A Case of Rheumatoid Neutrophilic Dermatitis with Annular Bullae Treated with Prednisone and Colchicine Combination Therapy

This report describes a 73-year-old female with rheumatoid neutrophilic dermatitis (RND), a distinct cutaneous manifestation associated with rheumatoid arthritis (RA), characterized by persistent annular blisters. Over six months, the patient developed erythematous plaques and annular blisters on the upper and lower limbs. She had a known history of RA and interstitial pneumonia. Serological tests revealed markedly elevated rheumatoid factor (RF,1260 IU/mL) and anti-cyclic citrullinated peptide (anti-CCP) antibody (>500 U/mL). Histopathological analysis demonstrated marked hyperkeratosis accompanied by neutrophilic aggregates in the stratum corneum, subepidermal blister formation, and dense neutrophilic infiltrates mixed with lymphocytes and eosinophils in the papillary to mid-dermis, while DIF was negative. The patient was treated with a combination of prednisone (30 mg qd) and colchicine (0.5 mg tid). After nearly one month of treatment, she experienced significant clinical improvement, with a marked reduction in RF-associated antibody levels and near-complete resolution of skin lesions.