Toxic Shock Syndrome

A. Overview

Toxins produced by various strains of bacteria
1. Staphylococcus aureus
2. Streptococcus pyogenes
3. Ehrlichia chaffeensis
These toxins stimulate T lymphocytes leading to activation
Activated T lymphocytes produce cytokines in large quantities
Production of large quantities of cytokines leads to symptoms
1. Skin rash
2. Endothelial dysfunction - including nitric oxide production
3. Hypotension
4. Capilary leak
5. Sepsis Syndrome may ensue

B. Clinical Diseases

Staphylococcal [9]
1. Women <30 years using tampons at highest risk [3,5]
2. Original descriptions in children with staphylococcal infections [4]
3. Majority of cases of TSS had vaginal cultures positive for staphylococcus
4. May occur with staphylococcal infections at other sites, often occult
5. Causative staphylococcal strains produce toxin TSST-1
6. TSST-1 is a "superantigen" encoded by a bacteriophage group 1
7. TSST-1 binds to T cell receptor ß2 chains and causes massive T cell stimulation
Streptococcus [1,6,7]
1. Group A streptococcus is a major cause of rheumatic fever, pharyngitis, tonsillitis
2. Well documented cause of Toxic Shock Syndrome
3. Similar syndromes found in some patients with Group C or G Streptococci [8]
4. Group A TSS is caused by non-rheumatogenic strains of S. pyogenes
5. These strains are also linked to post-streptococcal glomerulonephritis
6. Necrotizing fasciitis, with or without myonecrosis, is present in ~50% of cases
7. Group A ß-hemolytic S. pyogenes associated with scarlet fever also described [6]
8. The toxin responsible for Groups C or G toxic-shock like syndromes are not known [8]
9. Increased risk in American Indians
Ehrlichia [2]
1. Ehrlichiosis can be associated with a toxic-shock-like syndrome
2. Usually a benign rickettsial illness with rash and vomiting

C. Staphylococcal TSS

Fever - often >102°F
Nausea, Vomiting, Myalgias
Rash
1. Often with mucous membrane involvement
2. Desquamation of hands and feet may occur
Headache, Confusion
WBC > 15K/µL in ~50% of patients
Hypotension - quite refractory in many cases
Hepatitis, Renal Insufficiency, Thrombocytopenia
Respiratory Distress Syndrome (rare)

D. Streptococcal TSS [1,6,7]

Isolation of Streptococcus pyogenes (Group A Streptococcus)
1. Throat, Sputum, Vagina are most common primary sites
2. Blood, CSF, Pleural, Peritoneal Fluid cultures must be obtained
3. Blood cultures are often positive
4. Groups C and G Streptococcal toxic shock-like syndromes have been described [8]
Erythematous rash
1. Macular
2. Maculo-papular
Presence of necrotizing fasciitis in about 50% of cases
High fever, increased WBC as above

E. Treatment

Intensive supportive care is critical
Antistaphylococcal Antibiotics
1. Nafcillin or oxacillin preferred
2. Cefazolin may be substituted in penicillin allergic patients
3. Added gentamicin or rifampin for 2-3 days may improve bacterial clearance
Streptococcal TSS
1. In animal models, clindamycin appears to be more effective than penicillin
2. Use of combination clindamycin + penicillin is suggested [7]
3. No toxin-specific assays are currently available for general use
Drainage of any abscess; removal of infected mechanical devices
Role of glucocorticoids is unclear
Intravenous Immune Globulin (IVIg) may be helpful in staphylococcal infections [9]

References