Streptococcus milleri Group Cutaneous Abscess Associated with Insulin Injection to Distal Lower Extremity in an Insulin-Dependent Diabetic Man

Abstract

Purpose We report a case of Streptococcus milleri group (SMG)-associated cutaneous abscess in an older diabetic man. The infection developed after subcutaneous insulin injection to the distal lower extremity. This is the first known account of SMG-associated abscess secondary to insulin administration. Summary A 60-year-old Caucasian insulin-dependent diabetic male developed a severe cutaneous infection including abscess and surrounding cellulitis at the site of a self-administered insulin glargine injection on the medial portion of his right lower leg. The infection developed rapidly within 1 day following the injection. Cultures from purulent drainage were positive for SMG. The infection resolved rapidly with an antibiotic regimen including 1 dose of clindamycin followed by intravenous pipercillin/tazobactam plus vancomycin and concluded with outpatient treatment with sulfamethoxazole/trimethoprim. Organisms belonging to SMG are increasingly recognized as pyogenic pathogens responsible, most commonly, for abscess infections. SMG infections have been reported in diabetics; however, this is the first known case of SMG-associated abscess secondary to subcutaneous insulin administration. Conclusion A 60-year-old diabetic male experienced a severe SMG-associated abscess in the distal lower extremity after self-injection with insulin glargine. The infection resolved rapidly with intravenous and oral antibiotics. Clinicians should be aware of the potential for abscess infection from SMG at insulin injection sites.