Idiopathic refractory sweet’s syndrome with cardiopulmonary involvement

Background Sweet’s syndrome (SS) is a rare neutrophilic dermatosis characterized by fever, tender erythematous skin lesions, and neutrophilia of the blood and dermis that are generally responsive to steroids. Systemic involvement, particularly life-threatening cardiopulmonary complications, is exceedingly rare. We report a case of idiopathic refractory SS with extensive tracheobronchial, pulmonary, and cardiac involvement complicated by massive pericardial effusion and cardiac tamponade. The patient was successfully managed with pericardiocentesis, systemic corticosteroids and tocilizumab (an interleukin-6 receptor antagonist). This case highlights the novel use of tocilizumab in managing refractory idiopathic SS with cardiopulmonary involvement, emphasizing its therapeutic potential and the importance of early intervention. Case presentation : A 66-year-old woman presented with cough, fever, and bloody sputum. Initial chest CT revealed multiple pulmonary nodules. Anti-infective therapy is ineffective, and patients later develop erythematous skin lesions. Skin biopsy confirmed the presence of a SS. Systemic glucocorticoids improved symptoms, but the rash recurred repeatedly during tapering, accompanied by tracheobronchial wall thickening and massive pericardial effusion. Ultrasound-guided pericardiocentesis drained 400 mL of pericardial effusion fluid. Histopathological examination of the pericardial effusion cell block confirmed classical features consistent with those of a skin biopsy. The patient achieved sustained remission with combined tocilizumab and prednisone, and prednisone was successfully tapered to a maintenance dose of 5 mg daily. Conclusions This is the first reported case of the use of tocilizumab in combination with corticosteroids in the treatment of idiopathic refractory SS complicated with cardiopulmonary involvement. These results suggest that IL-6 (interleukin-6) pathway inhibition is a promising strategy for reducing the risk of relapse and glucocorticoid-related toxicity in patients with steroid-dependent SS. Early recognition of systemic complications and targeted biologic therapy may improve outcomes in refractory patients, warranting further research to validate long-term efficacy and mechanistic insights.