What is the best course of treatment for a patient with chest pain, fever, abnormal bowel movements, leukocytosis, mild anemia, and negative Dengue and Salmonella tests, initially treated with Paracetamol (acetaminophen)?

Management of Febrile Patient with Chest Pain, Leukocytosis, Mild Anemia, and Negative Dengue/Salmonella Tests

Immediate Priority: Rule Out Malaria and Acute Coronary Syndrome

This patient requires urgent malaria testing with thick and thin blood smears immediately, regardless of travel history disclosure, given the constellation of fever, chest pain, leukocytosis (WBC 14), and mild anemia (Hgb 104 g/L). 1 The negative Dengue and Salmonella tests narrow but do not complete the differential diagnosis, and the clinical presentation with fever plus chest pain demands exclusion of life-threatening conditions before attributing symptoms to simple gastroenteritis.

Critical Diagnostic Pathway

Step 1: Malaria Evaluation (Highest Priority)

• Obtain thick and thin blood smears stat - malaria remains the single predominant cause of systemic febrile illness and can present with chest pain, fever, and leukocytosis 1
• Approximately 50% of malaria patients are afebrile on presentation despite fever history, making this diagnosis easily missed 1
• The mild anemia (Hgb 104 g/L) and leukocytosis are consistent with malaria, particularly P. falciparum which can cause mild leukocytosis in severe cases 1
• Do not wait for travel history confirmation - many patients fail to disclose or recall brief exposures to endemic areas 1

Step 2: Cardiac Evaluation for Chest Pain

• Obtain ECG within 10 minutes of presentation for all patients with acute chest pain 2
• Measure high-sensitivity cardiac troponin immediately and repeat serially to identify rising/falling patterns 2
• A single normal ECG never rules out acute coronary syndrome - repeat ECG if chest pain recurs or persists 2
• Consider posterior leads (V7-V9) if standard ECG is nondiagnostic but clinical suspicion remains intermediate-to-high 2

Step 3: Invasive Bacterial Enterocolitis Assessment

• The combination of hard stool followed by loose stool with leukocytosis suggests evolving bacterial enterocolitis 1, 3
• Order stool studies including: 1, 3
  • Fecal leukocytes or lactoferrin
  • Bacterial cultures for Salmonella, Shigella, Campylobacter, E. coli O157:H7, and Yersinia
  • C. difficile toxin assay (given recent paracetamol use and potential healthcare exposure)
• Check urinalysis - the presence of pyuria and microhematuria would suggest concurrent UTI or systemic inflammatory response requiring broader evaluation 3

Risk Stratification and Management Decisions

High-Risk Features Requiring Immediate Intervention

If any of the following are present, escalate care immediately:

Malaria-Related:

• Parasitemia >1% on blood smear = severe malaria requiring IV artesunate and ICU admission 1
• Confusion, seizures, or reduced Glasgow Coma Scale = cerebral malaria 1
• Hypoglycemia, elevated lactate, or metabolic acidosis = severe malaria 1

Cardiac-Related:

• ST-segment elevation = STEMI requiring immediate reperfusion 2
• ST-segment depression or T-wave inversions = NSTE-ACS requiring admission and antiplatelet therapy 2
• Elevated troponin = myocardial injury requiring cardiology consultation 2

Sepsis-Related:

• Leukopenia with neutrophilia (paradoxical finding) = bone marrow exhaustion indicating overwhelming sepsis or neutropenic enterocolitis 3
• Hemodynamic instability, altered mental status, or signs of organ dysfunction = septic shock requiring ICU admission 3

Empirical Antibiotic Therapy Indications

Start empirical antibiotics immediately if: 1, 3

• Fever with bloody stools or fecal leukocytes/lactoferrin
• Signs of systemic toxicity (high fever >39°C, rigors, hypotension)
• Immunocompromised state or severe comorbidities
• Leukopenia with neutrophilia suggesting neutropenic enterocolitis

Antibiotic choice: 3

• For suspected neutropenic enterocolitis or severe sepsis: piperacillin-tazobactam, imipenem-cilastatin, or meropenem
• For uncomplicated bacterial enterocolitis: ciprofloxacin (if no recent travel to sub-Saharan Africa where resistance is common) or azithromycin 1
• Duration: 7-10 days, adjusted based on culture results 3

Conservative Management Pathway (If High-Risk Features Absent)

Supportive care includes: 1, 4

• Aggressive oral rehydration with ORS targeting >2500 mL daily 4
• Continue paracetamol 1000 mg every 8 hours (maximum 3000 mg/day to avoid hepatotoxicity) 5
• Avoid NSAIDs completely until malaria and dengue are definitively excluded due to bleeding risk 4, 6
• Monitor for warning signs: persistent vomiting, abdominal pain, lethargy, mucosal bleeding 4

Laboratory Monitoring Strategy

Daily Monitoring Required:

• Complete blood count to track WBC trend, hemoglobin, and platelet count 4, 3
• Electrolytes to guide replacement therapy 3
• Liver function tests if transaminitis suspected (common in dengue, malaria, and drug-induced injury) 7, 5

Specific Thresholds for Escalation:

• Platelet count <100,000/mm³ or rapidly declining = consider dengue despite negative test (may be too early in illness) 4
• Rising hematocrit >20% from baseline = plasma leakage suggesting severe dengue 4
• Creatinine >1.5 mg/dL = acute kidney injury requiring closer monitoring 1

Critical Pitfalls to Avoid

1. Never discharge a patient with chest pain based on a single normal ECG - serial ECGs and troponins are mandatory 2

2. Never assume negative Dengue test rules out dengue - testing performed <5 days after symptom onset may be falsely negative; IgM becomes positive only after day 5-7 4

3. Do not prescribe antibiotics empirically for presumed viral gastroenteritis without evidence of bacterial infection - this contributes to antimicrobial resistance without clinical benefit 3

4. Never exceed 3000 mg/day paracetamol in febrile patients - dengue and malaria patients are at increased risk for hepatotoxicity with excessive acetaminophen 5

5. Do not overlook malaria in patients without documented travel history - many patients fail to recall brief exposures or visiting friends/relatives in endemic areas 1

Disposition Criteria

Admit if Any of the Following:

• Positive malaria smear (any parasitemia level requires admission for monitoring) 1
• Elevated troponin or ischemic ECG changes 2
• Hemodynamic instability, altered mental status, or signs of sepsis 3
• Inability to tolerate oral fluids or signs of severe dehydration 4
• Thrombocytopenia <100,000/mm³ or rising hematocrit suggesting plasma leakage 4

Safe for Discharge if All of the Following:

• Negative malaria smears (thick and thin) 1
• Normal serial ECGs and troponins 2
• Hemodynamically stable with adequate oral intake 4
• No signs of severe bacterial infection or sepsis 3
• Reliable follow-up within 24-48 hours 1

Discharge Instructions:

• Return immediately for recurrent fever, persistent vomiting, chest pain, dyspnea, or altered mental status 4, 2
• Continue oral rehydration and paracetamol as needed (maximum 3000 mg/day) 4, 5
• Follow up in 24-48 hours for repeat CBC and clinical reassessment 4