Drug rash with eosinophilia and systemic symptoms syndrome masquerading as a lymphoproliferative disorder in a young adult on immunosuppressive therapy for rheumatoid arthritis: a case report

Background: This case reveals a novel presentation of drug rash with eosinophilia and systemic symptoms syndrome that mimics a lymphoproliferative disorder. The heterogeneous clinical presentation of drug rash with eosinophilia and systemic symptoms syndrome gives rise to a broad differential diagnosis that includes a multitude of infectious, inflammatory, and autoimmune conditions. This patient was diagnosed with drug rash with eosinophilia and systemic symptoms syndrome 4 weeks after starting sulfasalazine and 5 weeks after starting hydroxychloroquine for rheumatoid arthritis. Both of these medications have been shown to cause drug rash with eosinophilia and systemic symptoms syndrome, albeit more rarely in the context of hydroxychloroquine. This patient's history, physical examination, and workup illuminate a case of drug rash with eosinophilia and systemic symptoms syndrome that masquerades as a lymphoproliferative disorder despite its adherence to the RegiSCAR criteria.

Case presentation: A 22-year-old African-American female with an atopic history and rheumatoid arthritis presented for evaluation of a rash, unremitting fevers, and syncope. She was found to have drug rash with eosinophilia and systemic symptoms syndrome. A syncope workup was unremarkable. Computed tomography of the chest/abdomen/pelvis confirmed extensive lymphadenopathy and revealed a small right pleural effusion (Fig. 5). These imaging findings accompanied by fevers and a rash in the setting of eosinophilia, leukocytosis, and transaminitis led to the clinical suspicion for drug rash with eosinophilia and systemic symptoms syndrome. Steroids were subsequently initiated. Broad-spectrum antibiotic therapy was implemented to cover for possible skin/soft tissue infection due to initial paradoxical worsening after discontinuation of the culprit drugs. Lymph node biopsy ruled out a lymphoproliferative disorder and instead demonstrated necrotizing lymphadenitis. An extensive infectious and autoimmune workup was noncontributory. Clinical improvement was visualized, antibiotics were discontinued, and she was discharged on a steroid taper.

Conclusion: This case reflects how drug rash with eosinophilia and systemic symptoms syndrome can masquerade as a lymphoproliferative disorder. Additionally, it highlights the extent to which rapid identification and treatment optimized the patient's outcome. It calls into question how immunogenetics may factor into a patient's susceptibility to acquire drug rash with eosinophilia and systemic symptoms syndrome. This case is unique because of the early onset of visceral organ involvement, the type of internal organ involvement, the hematopoietic features, and the lymphadenopathy associated with a disease-modifying antirheumatic drug.