PO:11:162 | DRESS syndrome: a case treated with mepolizumab

Alessandro Belotti Masserini¹, Stefania Bertocchi¹, Eleonora Bruschi¹, Silvia Breda¹, Valeria Rossi¹, Elide Lupi¹, Tania Ubiali¹, Fabrizio Angeli¹, Massimiliano Limonta¹ | ¹ASST Papa Giovanni XXIII, Bergamo, Italy

Background. DRESS syndrome is a serious delayed drug hypersensitivity reaction and it’s a medical emergency that requires rapid recognition and treatment. Symptoms do not always occur immediately after drug administration, and this latency can make diagnosis difficult and delay identification of the causative drug. Corticosteroids are the first-line therapy. Endovenous immuniglobulines can be used in combination with corticosteroids, and cyclosporine is considered a second-line therapy for patients unresponsive to steroids. Biologics, such as anti-IL-5 agents, should be considered in refractory cases.

Materials and Methods. Retrospective data collection from the medical records. Results. A 50-year-old Caucasian patient was admitted on June 26th 2024, for pleuropericarditis, fever, and skin rash. He underwent treatment with indomethacin and colchicine, with initial benefit. On July 7th, dyspnea on exertion, increased pleural effusion, and worsening skin rash occurred, so oxygen therapy and antihistaminic treatment were started. Subsequently, pitting edema was observed in all four limbs, and the first evidence of hypereosinophilia (>13,000/mm³) was detected at the blood test on July 8th. Indomethacin and colchicine were discontinued due to suspected adverse reactions. In the suspicion of EGPA (eosinophilic granulomatosis with polyagitiis) the following were requested: skin biopsy (eosinophilic infiltrate without signs of vasculitis ENT, pulmonary, hematological (excluding organ involvements), and nephrological evaluations (no signs of glomerular disease). In the meantime, therapy with methylprednisolone 60 mg/day was started with subsequent reduction of the eosinophil count and stabilization of the pulmonary involvement, but worsening of renal function (creatinine 4.7 mg/dl), reduction of the platelet count (26,000/mm³), haptoglobin consumption, increased transaminases, reduction of C3 and C4, negativity of ANCA (Antineutrophil Cytoplasmatic Antibodies) PR3 (proteinase 3) and MPO (myeloproxidase) and increase of the hemolysis indices with schistocytes. In the suspicion of Hemolytic Uremic Syndrome he was treated with a cycle of plasmapheresis and Eculizumab. During hospitalization the patients began to complain about paresthesias with EMG documentation of polyneuropathy in the 4 limbs. Due to worsening of the respiratory symptoms, he underwent orotracheal intubation (26/07) and then tracheostomy. Subsequently, progressive improvement of the respiratory function was observed, with consequent removal of the tracheocannula, but worsening of the polyneuropathy and onset of bilateral ocular ischemic angiopathy. A diagnosis of DRESS was made, endovenous immunoglobulin therapy was initiated, and steroids were continued. Given the renal status and the concomitant infection (Pseudomonas in the respiratory material) treatment with mepolizumab 300 mg per month (for a total of 4 doses) was initiated over cyclosporine, with subsequent resolution of the DRESS.

Conclusions. Mepolizumab shew effectiveness in a case of refractory DRESS and may represent a valid alternative for the treatment of forms refractory to steroid and immunosuppressive therapy.