Pathogenesis of Toxic Shock Syndrome (TSS)

Toxic shock syndrome (TSS) is a toxin mediated, rare, life threatening, systemic illness caused due to infection of Staphylococcus aureus (staphylococcal toxic shock) and Streptococcus pyogens (rarer called streptococcal toxic shock). While the syndrome often occurs in menstruating women, it can also affect men, children and postmenopausal women.

Sources of infection:

  1. Vagina (superabsorbent tampon use)
  2. Barrier contraceptives (diaphragm or vaginal sponge)
  3. Nose (nasal packing)
  4. Surgical wound
  5. Childbirth
  6. Any skin wound, such as those from chickenpox

Pathogenesis of Toxic Shock Syndrome:

Pathogenesis of Toxic Shock Syndrome

Pathogenesis of Toxic Shock Syndrome - Click to enlarge

a. Bacterial Colonization:

  • TSS is initiated with the localized growth of toxin-producing strains of S.aureus in vagina or a wound

b. Exotoxin production:
Colonization is followed by the production and release of one or more pyrogenic exotoxins which acts as superantingen.
Toxins involved:

  • Major: TSST-1 (Toxic Shock Syndrome Toxin -1), Staphylococcal enterotoxin B
  • Minor: Entertoxins A, C, D, E

c. Immune response:

  1. Pyrogenic exotoxins behave as superantigens
  2. They don’t require processing by antigen presenting cells (APCs) but directly interact with class II MHC molecules
  3. Binding of superantigen-MHC complex with T-cell receptors causes polyclonal T-cell activation (up to 20% at a time)
  4. There is massive and dysregulated cytokine production (mainly TNF, IL-1, IL-6) termed as cytokine storm
  5. Interferon–gamma is also produced, which subsequently inhibits polyclonal immunoglobulin production

d. Shock and Tissue Injury:
Role of various cytokines:

  • IL-1: high fevers, myalgia
  • TNF: hypotension, edema
  • IL-2 and IFN-gamma: rash

Symptoms of Toxic Shock Syndrome:

  1. High fever and chills
  2. Hypotension
  3. Vomiting and Diarrhea
  4. Erythematous rashes leading to desquamation and hyperemia of mucous membranes
  5. Myalgia and elevated serum creatine phosphokinase
  6. Redness of eye, mouth, throat
  7. Confusion
  8. Multiple organ dysfunction

Diagnosis and Treatment:
@Mercksmanual

References:
Toxic shock syndrome – Emedicine Medscape
Toxic shock syndrome – Wikipedia
A textbook of Microbiology – Chakraborty

2 Comments
  1. November 29, 2011
    • December 4, 2011

Leave a Reply

Your email address will not be published. Required fields are marked *

banner