Thumbs up: A Case of Streptococcal Toxic Shock Syndrome

Summary: Dermatology evaluated a painless necrotic eschar on the right dorsal thumb of a 41-year-old male in the medical intensive care unit (MICU). Significant edema, erythema, and petechiae were noted on his distal extremities. One day prior to presentation, the patient had been in Aruba where he had consumed oysters and subsequently developed watery diarrhea and high fever. He was admitted to the local ICU for septic shock requiring pressors and intravenous fluids. He left that hospital against medical advice and returned to the United States with his central line still in place. He stated the wound had started as a “pimple” 4 days prior and quickly progressed. His wife had consumed the same meals in Aruba without similar symptoms. He denied any trauma, arthropod/animal, or water exposures. In the MICU, the patient was noted to have acute kidney injury, elevated CK, thrombocytopenia, mild anemia, elevated AST/ALT, and elevated indirect/direct bilirubin. Dermatology performed tissue biopsy for H&E, culture, and PCR. Extensive laboratory workup including parasite panel/smear, HIV, stool cultures, Zika virus, CMV, tick-borne disease panel, blood and urine cultures, C. difficile, respiratory panel, vibrio culture, arsenic levels, HSV, fungal culture, and cryoglobulins was negative. Venous duplex ultrasound revealed a nonocclusive DVT of the right lower extremity for which anticoagulation was started. Right hand X-ray was negative for soft tissue gas or osteomyelitis. While inpatient, he required one unit of platelets and was given one round of plasmapheresis due to concern for hemolysis from thrombotic thrombocytopenia purpura. Right dorsal thumb tissue biopsy demonstrated epidermal necrosis, hemorrhage, intravascular fibrin thrombi, and superficial to deep perivascular neutrophil-rich mixed inflammatory infiltrate consistent with deep soft tissue infection with secondary vascular thrombi. Tissue culture and broad-spectrum PCR & DNA sequence-based testing revealed growth of Streptococcus pyogenes. Clinicopathologic correlation confirmed a diagnosis of Streptococcal toxic shock syndrome (TSS), which per CDC guidelines includes group A Streptococcal infection, low blood pressure (i.e. “shock”), and problems with 2+ organ systems (i.e., “multiple organ failure”). Strep TSS is an exotoxin mediated disease which causes massive stimulation of T cells from underlying strep bacteremia or soft tissue infection. In our case, the patient revealed he was an emergency medicine physician who had recently performed a throat swab culture on a confirmed Streptococcus pharyngitis patient one week prior. He may have contacted the infectious bacteria at that time, with the painless eschar on his dorsal thumb representing the original site of inoculation. During his two-week hospitalization, he received courses of IV cefepime, vancomycin, and doxycycline and was discharged home on amoxicillin, doxycycline, and three-month course of anticoagulation. At one-month follow-up, the patient’s eschar had healed into a crusted plaque, his edema had resolved, and his bilateral lower extremities had returned to normal.