Toxic Shock Syndrome

Toxic shock syndrome (TSS) is an acute toxin-mediated illness in which bacterial toxins trigger widespread inflammation, vascular leakage, and circulatory collapse. It can be caused by toxin-producing Staphylococcus aureus or group A Streptococcus (GAS). Streptococcal toxic shock syndrome (STSS) is particularly associated with invasive soft-tissue infection and can progress to shock and multiorgan dysfunction within a short period. In STSS, exotoxins act as superantigens. Rather than activating a small number of T cells through the usual antigen-specific pathway, they activate a large, nonspecific population at once. The resulting cytokine surge produces vasodilation and capillary leak, so the patient loses effective circulating volume even when total body fluid has not yet been lost. Tissue perfusion falls; the kidneys, lungs, liver, brain, and coagulation system may then become injured. This mechanism explains why a patient may deteriorate quickly and why a dramatic local wound is not required. The systemic toxin response, not the size of the visible lesion, determines the immediate threat.