G600(P) A case of myocarditis developing despite treatment for drug reaction with eosinophilia and system symptoms (DRESS) syndrome

Aim We present a case of an eight year old girl who was treated with intravenous antibiotics for group A streptococcus (GAS) peritonitis. She subsequently became severely unwell with skin rash and multiorgan dysfunction syndrome. A rare complication and unusual progress are described. Results The patient had a background of ventriculoperitoneal (VP) shunt for hydrocephalus at five months of age. She was transferred in mid March 2019 to the tertiary hospital with abdominal sepsis. In the first two weeks she had surgical and neurosurgical interventions on three occasions. Chains of gram positive cocci were seen in peritoneal fluid and GAS was identified from cerebrospinal fluid. Treatment was ceftriaxone and metronidazole. Five weeks later she developed a morbilliform rash, fever, eosinophilia, renal, liver impairment and lactic acidosis. She was admitted to PICU, requiring intubation and multiorgan support. The working diagnosis was DRESS syndrome using the Japanese consensus group diagnostic criteria. Stopping antibiotics was advised, but instead they were changed (to meropenem and vancomycin), and she was treated with steroids. She clinically improved shortly before having a further significant clinical deterioration with myocarditis. Her atrial natriuretic peptide was more than 70,000 pg/ml and troponin-T raised at a level of 243 ng/L. Because myocarditis was not expected, a wider differential was considered including sepsis and rheumatic fever (revised Jones criteria met: rising GAS titre, carditis, rash, fever, high inflammatory markers). Although American College for Rheumatology criteria not fully met as did not have tissue biopsy, eosinophilic granulomatosis with polyangitis was also considered (criteria met: eosinophilia, lung infiltrates on CT of chest, neuropathy ). She improved with milrinone, pulsed high dose methyl-prednisolone, cyclophosphamide and plasma exchange. Later, lymphocyte transformation assays showed responses to ceftriaxone and vancomycin, but not to other agents. Conclusions This is a rare case where DRESS myocarditis developed despite appropriate medication change and treatment with steroids. Clinical multidisciplinary team decision making was key to securing an optimal outcome.