What is the appropriate management for patients in the US presenting with severe gastrointestinal symptoms, such as nausea, vomiting, diarrhea, and abdominal pain, who test positive for streptococcal (strep) infection without throat pain?

Atypical Streptococcal Presentation with Gastrointestinal Symptoms

Direct Answer

There is no documented new strain of Group A Streptococcus causing predominantly gastrointestinal symptoms in the US, but severe invasive GAS infections can present with GI symptoms as the primary manifestation, and these cases carry a 30% mortality rate. 1

Understanding This Clinical Presentation

Invasive GAS with GI Symptoms is a Recognized Entity

• Gastrointestinal symptoms can be the primary presenting sign of severe invasive Group A Streptococcal infection, with 40 out of 409 invasive GAS cases (approximately 10%) presenting primarily with GI symptoms in Danish surveillance data. 1
• The mortality rate for invasive GAS cases presenting with GI symptoms reaches 30%, significantly higher than the overall 18% mortality rate for all invasive GAS infections. 1
• Fatal cases have been documented where patients aged 12-25 years presented with nausea, diarrhea, and vomiting for less than 2 days to 2 weeks before death, with no underlying diseases. 1

Critical Diagnostic Pitfall

The absence of throat pain does not rule out streptococcal infection. The clinical challenge here is that you're likely dealing with one of two scenarios:

1. Invasive GAS infection (streptococcal toxic shock syndrome or necrotizing fasciitis) where GI symptoms dominate
2. Coincidental GAS pharyngeal colonization (25% of household contacts carry GAS asymptomatically) 2 with a concurrent viral gastroenteritis

Diagnostic Algorithm

Step 1: Risk Stratification for Invasive Disease

Look for these red flags suggesting invasive GAS rather than simple pharyngitis:

• Severe systemic toxicity - appears critically ill beyond what gastroenteritis would explain 1
• Hypotension or shock 1
• Organ dysfunction 1
• Soft tissue findings - pain out of proportion to examination, erythema, swelling (necrotizing fasciitis often enters through skin, not throat) 3
• Rapid progression - symptoms worsening over hours rather than days 1

Step 2: Determine if Throat Testing is Even Indicated

Do NOT test for strep throat if viral features dominate:

• Cough, rhinorrhea, conjunctivitis, hoarseness, or oral ulcers argue strongly against GAS pharyngitis 4
• Diarrhea is more common with viral pharyngitis 5
• The presence of these viral features means testing should not be performed 4

Step 3: If Testing is Appropriate, Confirm with Laboratory

• Never treat based on clinical symptoms alone - up to 70% of sore throat patients receive unnecessary antibiotics when treated empirically 2
• Use rapid antigen detection test (RADT) first, with 80-90% sensitivity and ≥95% specificity 2
• In children/adolescents, negative RADT requires backup throat culture 2
• In adults, negative RADT alone is sufficient 2

Management Based on Clinical Scenario

If Patient Appears Toxic or Has Invasive Disease Features

This is a medical emergency requiring immediate hospitalization:

• Blood cultures before antibiotics 1
• Broad-spectrum IV antibiotics covering invasive GAS (not just oral penicillin for pharyngitis) 1
• Surgical consultation if soft tissue involvement suspected 3
• Aggressive fluid resuscitation and ICU-level monitoring 1

If Patient Has Mild-Moderate Illness with Positive Strep Test

Treat with standard regimen for GAS pharyngitis:

• Penicillin V or amoxicillin for 10 days remains first-line due to narrow spectrum, proven efficacy, safety, and low cost 6
• Penicillin V dosing: 250 mg PO 2-3 times daily (children) or 250 mg 3-4 times daily or 500 mg twice daily (adolescents/adults) for 10 days 2
• For penicillin-allergic patients: first-generation cephalosporin (if not anaphylactic allergy), clindamycin, or clarithromycin for 10 days 6
• Note significant resistance to azithromycin and clarithromycin exists in some US regions 7

If Patient Has GI Symptoms with Negative Strep Test

Withhold antibiotics and provide symptomatic care only:

• A negative RADT in adults is sufficient to rule out GAS pharyngitis without backup culture 8
• Discontinue antimicrobial therapy for patients with negative throat cultures - this is a key quality indicator 8
• Provide analgesics (ibuprofen or acetaminophen) for symptom relief 8
• Most cases are viral and self-limiting 8

Addressing the "New Strain" Question

No Evidence of Novel Strain

• The Danish cases with GI presentations involved common GAS types (T-type 3-13-B3264, emm89 and T-type 1, emm1) that were similar to isolates from non-fatal cases elsewhere 1
• Penicillin resistance has never been documented in Group A Streptococcus 6, 2
• The various early clinical manifestations of severe GAS infections remain "a major challenge for clinicians" but are not new 1

What May Be Happening in Your Community

• Increased recognition of invasive GAS presentations that were always possible but underappreciated
• Coincidental viral gastroenteritis outbreak in a population with high GAS pharyngeal carriage rates (up to 25% of household contacts) 2
• Testing bias - patients with GI symptoms getting throat swabs they wouldn't normally receive, detecting asymptomatic carriers

Critical Pitfalls to Avoid

• Do not treat asymptomatic household contacts - even with confirmed GAS in the family, prophylactic treatment is not indicated and does not reduce subsequent infection rates 2
• Do not perform routine post-treatment cultures in asymptomatic patients who completed appropriate therapy 2
• Do not assume positive strep test explains GI symptoms - consider whether this represents true infection versus carriage with concurrent viral illness 6
• Do not miss invasive disease - if the patient appears more ill than simple gastroenteritis or pharyngitis would explain, escalate care immediately 1

When to Reevaluate

• Worsening symptoms after appropriate antibiotic initiation 7
• Symptoms lasting >5 days after starting treatment 7
• Development of shock, severe pain, or soft tissue changes 1