Purpura fulminans caused by Streptococcus pneumoniae serotype 23A in a young post-splenectomy man: A case report.

Purpura fulminans is a rare but severe complication of septic shock, often associated with Streptococcus pneumoniae infection in asplenic individuals, with high mortality and limb amputation risk. Although pneumococcal vaccines are available, infections caused by non-vaccine serotypes remain a major concern. A 39-year-old man with a history of splenectomy 18 years prior presented with dyspnea, malaise, and gastrointestinal symptoms for two days. He had never received pneumococcal vaccination following his splenectomy. On arrival, he was hypotensive, tachycardic, and exhibited signs of multi-organ failure with severe coagulopathy. Physical examination revealed widespread cyanosis and purpura. Blood cultures yielded penicillin-susceptible S. pneumoniae, later identified as serotype 23A (Sequence Type 5242), which is not included in currently available vaccines in Japan. Despite prompt intensive care, including broad-spectrum antibiotics, vasopressors, continuous renal replacement therapy, and mechanical ventilation, the patient developed progressive skin necrosis at the distal extremities. Ultimately, he required amputation of all 4 limbs. This case underscores the catastrophic consequences of overwhelming post-splenectomy infection due to a non-vaccine S. pneumoniae serotype in an unvaccinated asplenic adult. Early recognition and aggressive management are essential to save lives, but structured, lifelong pneumococcal vaccination and increased awareness among clinicians and patients remain paramount.