Skip to content
How It Works
Explore
Resources Ask a Question
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Ask a Question
PubMed This is a summary of 18 peer-reviewed journal articles Updated
Intensive Care Medicine

Confirming the Diagnosis: Clinical and Lab Evidence

At a Glance

Toxic Shock Syndrome (TSS) is primarily a clinical diagnosis based on symptoms like sudden high fever, sunburn-like rash, low blood pressure, and multi-organ distress. Because the illness moves rapidly, doctors often begin life-saving treatment before all lab tests confirm the infection.

Confirming a diagnosis of Toxic Shock Syndrome (TSS) is complex because it is primarily a clinical diagnosis, meaning it is based on a collection of symptoms rather than a single blood test [1][2]. Doctors use specific sets of criteria established by health organizations to categorize a case as “confirmed” or “probable.”

How Doctors Define TSS

While the symptoms of Staph and Strep TSS overlap, the official checklists used to diagnose them are different.

Staphylococcal (Staph) TSS

The CDC defines a “confirmed” case of Staph TSS by a strict checklist of symptoms [3][4]:

  1. High Fever: Temperature ≥\ge 38.9°C (102°F).
  2. Diffuse Rash: A flat, red rash (erythroderma) that looks like a sunburn.
  3. Hypotension: Low blood pressure (systolic ≤\le 90 mmHg).
  4. Multisystem Involvement: Damage to at least three organ systems (see the checklist below).
  5. Desquamation: Peeling of the skin, typically on the palms and soles [5].

An Important Note on Desquamation: Desquamation happens 1-2 weeks after the onset of the illness. ICU doctors do not wait for the skin to peel before starting life-saving treatment [5]. This strict CDC definition is often used retrospectively to formally confirm the disease, while clinical teams act immediately on the early signs of shock and rash [6].

Streptococcal (Strep) TSS

The criteria for Strep TSS, established by the Working Group on Severe Streptococcal Infections, are focused on the presence of shock and organ failure alongside the isolation of Streptococcus pyogenes [7][8]. A case is “definite” if the bacteria are found in a normally sterile site and “probable” if they are found in a non-sterile site [7].

Understanding “Normally Sterile Sites”

In microbiology, a normally sterile site is a part of the body where bacteria should never be present [9]. Finding bacteria here is a major “red flag” for a severe, invasive infection.

  • Sterile Sites: Blood, cerebrospinal fluid (CSF), joint fluid, or the fluid around the heart (pericardial) or lungs (pleural) [10][11].
  • Non-Sterile Sites: Areas where bacteria are common, such as the skin, throat, or vagina. If bacteria are found here, doctors must use the patient’s symptoms to decide if it is truly TSS [12][13].

The Diagnostic Checklist

When reviewing medical records or lab reports, you should look for evidence of how the bacteria affected different systems. A diagnosis typically requires at least three of these to be “abnormal” [3][14].

System What to Look For in Reports What it Means
Gastrointestinal Severe vomiting or diarrhea at the start of illness [3]. The body’s immediate reaction to toxins.
Mucous Membranes Hyperemia (severe redness) in the vagina, throat, or conjunctiva (eyes) [4]. Indicates massive vascular inflammation; very common in menstrual TSS.
Renal (Kidneys) Creatinine levels at least twice the normal limit [15]. Acute Kidney Injury (AKI) is a common early sign of TSS [15].
Hematologic Thrombocytopenia (platelet count < 100,000/mm³) [16]. Low platelets indicate the blood’s clotting system is under stress [17].
Hepatic (Liver) Elevated liver enzymes (AST, ALT, or Bilirubin) twice the normal limit [3]. Indicates the liver is struggling to process the inflammation.
Muscular Severe muscle pain (myalgia) or high Creatine Phosphokinase (CPK) [3]. A sign of muscle tissue breakdown caused by the toxins.
Central Nervous System Disorientation or confusion without a clear cause [3]. Often called “toxic encephalopathy” due to low oxygen and high toxins.

Why Early Diagnosis is Hard

It is important to know that many patients do not meet all these criteria when they first arrive at the ICU [18]. Because TSS moves so fast, doctors often start treatment (like broad-spectrum antibiotics and fluids) based on clinical suspicion before every lab test is back [18][5]. Waiting for “confirmed” status can be dangerous, so your care team likely acted before the paperwork was complete [6].

Common questions in this guide

What is the difference between Staph and Strep TSS?
Staph TSS is diagnosed using a strict checklist including high fever, rash, low blood pressure, and multi-organ involvement. Strep TSS focuses heavily on the presence of shock and organ failure along with the isolation of Streptococcus pyogenes bacteria.
What does it mean if bacteria is found in a sterile site?
A normally sterile site is an area of the body where bacteria should never be present, like the blood or spinal fluid. Finding bacteria in these areas is a strong indicator of a severe, invasive infection like Toxic Shock Syndrome.
Why did my doctor start TSS treatment before all my lab tests came back?
Toxic Shock Syndrome progresses extremely quickly, making it dangerous to wait for lab confirmation. Doctors often start life-saving treatments based on early clinical signs like shock and rash before all the test results are finalized.
Will my skin always peel if I have Toxic Shock Syndrome?
Skin peeling, or desquamation, usually happens one to two weeks after the illness begins, most often on the palms and soles. However, not every patient experiences this, and doctors do not wait for it to happen before starting treatment.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Did the culture results identify Streptococcus pyogenes (Group A Strep) or Staphylococcus aureus?
  2. 2.Was the bacteria isolated from a 'normally sterile site' like my blood, or from a non-sterile site like a surface wound?
  3. 3.At the time of admission, which of the three organ systems (renal, hepatic, hematologic, etc.) were showing signs of dysfunction?
  4. 4.If my skin did not immediately peel in the ICU, does the clinical team still suspect TSS based on other multi-system criteria?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (18)
  1. 1

    A Rare Case of Staphylococcal Toxic Shock Syndrome in a Neonate.

    Shrestha N, Joshi A, Hayashi Y, et al.

    Case reports in infectious diseases 2022; (2022()):8111620 doi:10.1155/2022/8111620.

    PMID: 35686114
  2. 2

    Staphylococcal enterotoxin B- and lipopolysaccharide-induced toxic shock syndrome in a burn patient.

    Yamasaki O, Sugihara S, Kajita A, et al.

    The Journal of dermatology 2021; (48(4)):547-550 doi:10.1111/1346-8138.15729.

    PMID: 33410193
  3. 3

    Toxic Shock Syndrome: Eighteen Years of Experience in a Pediatric Intensive Care Unit.

    Cascais I, Losa A, Correia C, et al.

    Cureus 2024; (16(1)):e52898 doi:10.7759/cureus.52898.

    PMID: 38406070
  4. 4

    An overlooked cause of septic shock: Staphylococcal Toxic Shock Syndrome secondary to an axillary abscess.

    Poudel B, Zhang Q, Trongtorsak A, et al.

    IDCases 2021; (23()):e01039 doi:10.1016/j.idcr.2020.e01039.

    PMID: 33473349
  5. 5

    Menstrual toxic shock syndrome: case report and systematic review of the literature.

    Berger S, Kunerl A, Wasmuth S, et al.

    The Lancet. Infectious diseases 2019; (19(9)):e313-e321 doi:10.1016/S1473-3099(19)30041-6.

    PMID: 31151811
  6. 6

    Staphylococcal toxic shock syndrome in a lactating mother with breast abscess: A case report.

    Pandit K, Khanal S, Adhikari P, et al.

    Annals of medicine and surgery (2012) 2020; (57()):133-136 doi:10.1016/j.amsu.2020.07.027.

    PMID: 32760582
  7. 7

    Similarities and Differences Between Staphylococcal and Streptococcal Toxic Shock Syndromes in Children: Results From a 30-Case Cohort.

    Javouhey E, Bolze PA, Jamen C, et al.

    Frontiers in pediatrics 2018; (6()):360 doi:10.3389/fped.2018.00360.

    PMID: 30547021
  8. 8

    Emerging infection: streptococcal toxic shock-like syndrome caused by group B Streptococcus (GBS), Streptococcus agalactiae.

    Rajack F, Medford S, Ramadan A, Naab T

    Autopsy & case reports 2024; (14()):e2024497 doi:10.4322/acr.2024.497.

    PMID: 39021470
  9. 9

    ICU Management of Invasive β-Hemolytic Streptococcal Infections.

    Babiker A, Kadri SS

    Infectious disease clinics of North America 2022; (36(4)):861-887 doi:10.1016/j.idc.2022.07.007.

    PMID: 36328640
  10. 10

    Comparison of 16S Ribosomal RNA Targeted Sequencing and Culture for Bacterial Identification in Normally Sterile Body Fluid Samples: Report of a 10-Year Clinical Laboratory Review.

    Yoo IY, Kang OK, Lee MK, et al.

    Annals of laboratory medicine 2020; (40(1)):63-67 doi:10.3343/alm.2020.40.1.63.

    PMID: 31432641
  11. 11

    A Comprehensive Study of Bacterial Etiological Agents in Sterile Body Fluids and Antimicrobial Susceptibility Patterns Among Hospitalized Patients at an Academic Medical Center in India.

    Patel R, Pawar S, Patil S

    Cureus 2024; (16(10)):e71862 doi:10.7759/cureus.71862.

    PMID: 39559643
  12. 12

    Invasive Group A Streptococcal Infections Among People Who Inject Drugs and People Experiencing Homelessness in the United States, 2010-2017.

    Valenciano SJ, Onukwube J, Spiller MW, et al.

    Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2021; (73(11)):e3718-e3726 doi:10.1093/cid/ciaa787.

    PMID: 32803254
  13. 13

    Increase in invasive group A streptococcal disease among Australian children coinciding with northern hemisphere surges.

    Abo YN, Oliver J, McMinn A, et al.

    The Lancet regional health. Western Pacific 2023; (41()):100873 doi:10.1016/j.lanwpc.2023.100873.

    PMID: 38223399
  14. 14

    Clinical Profile, Intensive Care Needs, and Short-Term Outcome of Toxic Shock Syndrome Among Children: A 10-Year Single-Centre Experience from North India.

    Angurana SK, Awasthi P, K C S, et al.

    Indian journal of pediatrics 2023; (90(4)):334-340 doi:10.1007/s12098-022-04271-4.

    PMID: 35804287
  15. 15

    Acute kidney injury in pediatric toxic shock syndrome is associated with worse clinical course in the intensive care unit.

    Weissbach A, Kaplan E, Kadmon G, et al.

    European journal of pediatrics 2023; (182(9)):4253-4261 doi:10.1007/s00431-023-05109-7.

    PMID: 37458817
  16. 16

    TSST-1 protein exerts indirect effect on platelet activation and apoptosis.

    Guo M, Yi T, Wang Q, et al.

    Platelets 2022; (33(7)):998-1008 doi:10.1080/09537104.2022.2026907.

    PMID: 35073811
  17. 17

    The Evaluation and Management of Toxic Shock Syndrome in the Emergency Department: A Review of the Literature.

    Gottlieb M, Long B, Koyfman A

    The Journal of emergency medicine 2018; (54(6)):807-814 doi:10.1016/j.jemermed.2017.12.048.

    PMID: 29366615
  18. 18

    Menstrual Toxic Shock Syndrome: A French Nationwide Multicenter Retrospective Study.

    Contou D, Colin G, Travert B, et al.

    Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2022; (74(2)):246-253 doi:10.1093/cid/ciab378.

    PMID: 33906228

This page provides educational information about the diagnostic criteria for Toxic Shock Syndrome. It does not replace professional medical advice, and you should always consult your healthcare provider or emergency services if you suspect TSS.

Get notified when new evidence is published on Bacterial toxic-shock syndrome.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.