Staphylococcal Toxic-Shock Syndrome

Staphylococcal toxic shock syndrome (staphylococcal TSS) is an acute disease mediated by the production of superantigenic toxins, characterized by high fever, skin rash followed by skin peeling, hypotension, vomiting, diarrhea and potentially leading to multisystem organ failure and caused by a Staphylococcus aureus bacterial infection.

Epidemiology

The incidence of staphylococcal TSS in the United States ranges from 1/192,000 - 1/156,000 people/year. With menstrual TSS now reduced by changes in tampon use, non-menstrual TSS represents up to 50% of staphylococcal TSS cases.

Clinical description

Staphylococcal TSS is seen most commonly in otherwise healthy adult women. However non-menstrual staphylococcal TSS can also be observed in men and children. Onset is sudden and includes high fever (> 38.9°C), nausea, diarrhea, vomiting, myalgia, abdominal pain and sore throat. Unlike streptococcal TSS (see this term), a generalized rash is seen in most cases of staphylococcal TSS, occurring within the first 2 days of symptom onset and affecting both the mucosa and the skin. Later during convalescence, skin peeling also occurs. More serious manifestations include confusion, shock, renal and myocardial dysfunction and acute respiratory distress syndrome (ARDS; see this term). ARDS is the most common cause of death seen in staphylococcal TSS.

Etiology

Staphylococcal TSS is due to an infection with Staphylococcus aureus, that releases toxins and causes a massive immune reaction involving mainly cytokines and chemokines. This reaction is related to the activation of T cells by the production of superantigens that circumvent the normal pathway of antigen presentation. It was originally often associated with high absorbency tampon use, but also intravaginal devices (i.e. barrier contraceptive, menstrual cup) and infections following surgical procedures. Currently, many cases of Staphylococcal TSS are complications of suppurative infections or upper airways colonization.

Diagnostic methods

Diagnosis of staphylococcal TSS is suspected when rash followed by skin peeling, shock and involvement of at least three other organs are clinically observed. Laboratory analysis, where staphylococcal superantigens (such as toxic shock syndrome toxin 1) are identified in urine or serum, can aid in confirming diagnosis. Blood cultures are rarely positive for staphylococci.

Differential diagnosis

Differential diagnoses include streptococcal TSS, Rocky Mountain spotted fever, leptospirosis, dengue fever, typhoid fever (see these terms), peritonitis, pneumonia, pelvic inflammatory disease, pericarditis and acute myocardial infarction, meningococcemia, viral/ drug/allergic rash and septic shock.

Management and treatment

The onset of staphylococcal TSS is sudden and requires immediate medical treatment in an intensive care unit. Treatment of staphylococcal TSS involves antibiotics (clindamycin) along with supportive therapy (fluid resuscitation, inotropes and vassopressors) and intravenous immunoglobins (IVIGs) that block superantigens. Corticosteroids and recombinant activated protein C (derotrecogin-alpha) can also be helpful in some cases. Dialysis may be necessary for those with renal dysfunction and oxygen supplementation along with mechanical ventilation is required for patients with ARDS. Vancomycin and linezolid can be used in penicillin-allergic patients or when the strain is resistant to the methicillin. Women should refrain from using intravaginal devices, unless necessary, in order to minimize the risk of menstrual related staphylococcal TSS.

Prognosis

The prognosis is usually good. Staphylococcal TSS has a mortality rate of only 1-6%.