Recurrent SDSE bacteraemia resulting in streptococcal toxic shock syndrome in a patient with Noonan syndrome

A 19-year-old man with chronic lymphoedema due to Noonan syndrome presented at our hospital with septic shock and pain in his lower leg. Blood cultures were positive for Streptococcus dysgalactiae subsp equisimilis (SDSE), resulting in a diagnosis of cellulitis with toxic involvement. He was treated with ampicillin for 3 weeks. Although he did well for 6 weeks, septic shock recurred. Blood culture again revealed SDSE, with the strain being identical to the first episode, suggesting that this infection had relapsed. He was treated with ampicillin for 6 weeks and prophylactically with trimethoprim-sulfamethoxazole for 12 months. Although SDSE bacteraemia occurs commonly in elderly patients, findings in this patient showed that it can also develop in younger persons with predisposing factors. This case also indicates that SDSE has the potential to recur, despite generally sufficient antibiotic administration, and that patients who experience recurrent episodes may require prolonged treatment with antibiotics, including prophylaxis.