Toxic shock syndrome is a rare, life-threatening illness that is caused by toxins that circulate in the bloodstream. The toxins are released by some strains of the bacteria Staphylococcus aureus and/or Streptococcus pyogenes. It can cause failure of multiple organ systems in the body. It can occur after a trauma to the skin, pharynx, or vagina (the most common cause being prolonged tampon exposure).