[1] TSS is typically caused by bacteria of the Streptococcus pyogenes or Staphylococcus aureus type, though others may also be involved.

[1] Risk factors for the staphylococcal type include the use of very absorbent tampons, skin lesions in young children characterized by fever, low blood pressure, rash, vomiting and/or diarrhea, and multiorgan failure.

[1][7] The need for rapid removal of infected tissue via surgery in those with a streptococcal cause, while commonly recommended, is poorly supported by the evidence.

TSS resulting from infection with the bacterium Staphylococcus aureus typically manifests in otherwise healthy individuals via signs and symptoms including high fever, accompanied by low blood pressure, malaise and confusion,[3] which can rapidly progress to stupor, coma, and multiple organ failure.

[3] The initial presentation of symptoms can be hard to differentiate from septic shock and other conditions such as Rocky Mountain spotted fever, rubeola, leptospirosis, drug toxicities, and viral exanthems.

[8] STSS caused by the bacterium Streptococcus pyogenes, or TSLS, typically presents in people with pre-existing skin infections with the bacteria.

These individuals often experience severe pain at the site of the skin infection, followed by rapid progression of symptoms as described above for TSS.

The gene encoding toxic shock syndrome toxin is carried by a mobile genetic element of S. aureus in the SaPI family of pathogenicity islands.

In typical T-cell recognition, an antigen is taken up by an antigen-presenting cell, processed, expressed on the cell surface in complex with class II major histocompatibility complex (MHC) in a groove formed by the alpha and beta chains of class II MHC, and recognized by an antigen-specific T-cell receptor.

Superantigens do not require processing by antigen-presenting cells but instead, interact directly with the invariant region of the class II MHC molecule.

[17] During menstruation:[20] For anyone:[21] Staphylococcal toxic shock syndrome is rare and the number of reported cases has declined significantly since the 1980s.

[20] The term "toxic shock syndrome" was first used in 1978 by a Denver pediatrician, James K. Todd, to describe the staphylococcal illness in three boys and four girls aged 8–17 years.

The authors of the study noted reports of similar staphylococcal illnesses had appeared occasionally as far back as 1927, but the authors at the time failed to consider the possibility of a connection between toxic shock syndrome and tampon use, as three of the girls who were menstruating when the illness developed were using tampons.

[29] Following controversial test marketing in Rochester, New York, and Fort Wayne, Indiana,[30] in August 1978, Procter and Gamble introduced superabsorbent Rely tampons to the United States market[31] in response to demands for tampons that could contain an entire menstrual flow without leaking or replacement.

The Toxic Shock Syndrome Task Force was created and investigated the epidemic as the number of reported cases rose throughout the summer of 1980.

As part of the voluntary recall, Procter and Gamble entered into a consent agreement with the FDA "providing for a program for notification to consumers and retrieval of the product from the market".

[42] The ability of carboxymethylcellulose to filter the S. aureus toxin that causes TSS may account for the increased risk associated with Rely.