Septic Vasculitis as a Manifestation of Invasive Infection by Community-Acquired Methicillin-Resistant Staphylococcus aureus: A Pediatric Case Report.

Septic vasculitis (SV) is an uncommon complication of bacterial sepsis, characterized by inflammation and thrombosis of small- and medium-sized blood vessels. Although it is most often associated with meningococcemia, cases linked to Staphylococcus aureus have been reported. Presented is the case of a previously healthy adolescent who developed SV as an initial manifestation of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) bacteremia. The patient presented with fever, abdominal pain, and purpuric skin lesions, without any known exposure to typical risk factors. Initial clinical suspicion included loxoscelism, a necrotic arachnidism caused by Loxosceles spider bites, based on initial skin lesion morphology. However, further evaluation ruled out loxoscelism and autoimmune etiologies. Subsequent investigations confirmed MRSA infection through blood cultures, while skin biopsy revealed histological features of cutaneous vasculitis, establishing the diagnosis of SV. Imaging identified secondary infectious foci in the spleen, kidneys, and bone, though no surgical intervention was necessary. The case was managed with targeted antibiotic therapy, resulting in complete clinical recovery. This case underscores the importance of recognizing SV as a rare but serious initial manifestation of invasive bacterial infection in children and highlights the diagnostic value of skin findings in febrile illnesses, emphasizing the need for prompt and comprehensive etiological investigation.