A 3 year old girl, who weighs 12 kg, presents with a history of loose stools mixed with blood and mucus, and fever for 3 days. On examination, she is active and feeling excessively thirsty. There is some loss of skin turgor.

Differential Diagnosis

The clinical presentation suggests several possible diagnoses:

• Bacterial Dysentery (Shigellosis): Highly likely given the fever, bloody stools, and mucus. Shigella species are common causes of dysentery in young children.
• Campylobacter Enteritis: Another bacterial cause of bloody diarrhea, often associated with fever and abdominal pain.
• Salmonellosis: Can present with bloody diarrhea, especially in young children.
• Entamoeba histolytica (Amebic Dysentery): Less common in developed countries, but should be considered, especially with travel history.
• Intussusception: Although typically presenting with intermittent abdominal pain and “currant jelly” stools, bloody stools can occur. The child’s activity level makes this less likely, but it should remain in the differential.
• Henoch-Schönlein Purpura (HSP): A systemic vasculitis that can present with abdominal pain, bloody diarrhea, and a characteristic rash.
• Inflammatory Bowel Disease (IBD): Less common in this age group, but should be considered if symptoms are chronic or recurrent.

Investigations

A systematic approach to investigations is essential:

• Stool Routine Examination & Microscopy: To identify the presence of blood, mucus, leukocytes, and parasites.
• Stool Culture: To identify bacterial pathogens (Shigella, Salmonella, Campylobacter).
• Stool for Entamoeba histolytica: Microscopic examination for trophozoites and cysts.
• Complete Blood Count (CBC): To assess for anemia, leukocytosis (suggesting bacterial infection), and thrombocytopenia.
• Electrolyte Panel: To assess for dehydration and electrolyte imbalances (sodium, potassium, chloride).
• Kidney Function Tests (KFT): To assess renal function, especially if dehydration is significant.
• C-Reactive Protein (CRP): To assess the degree of inflammation.
• Consider Intussusception workup: If clinical suspicion is high, abdominal X-ray or ultrasound may be needed.

Initial Management

The immediate priorities are to address dehydration and provide supportive care:

• Fluid Resuscitation: Given the loss of skin turgor and thirst, the child is likely dehydrated. Initiate intravenous (IV) fluid resuscitation with a crystalloid solution (e.g., Normal Saline or Ringer's Lactate). The amount of fluid required will depend on the degree of dehydration, estimated based on weight and clinical assessment. A reasonable starting point for moderate dehydration (5-10%) in a 12 kg child is 60-80 ml/kg over 4-6 hours.
• Electrolyte Correction: Monitor and correct any electrolyte imbalances identified in the electrolyte panel.
• Antipyretics: Administer antipyretics (e.g., Paracetamol) to manage fever.
• Empiric Antibiotic Therapy: While awaiting stool culture results, empiric antibiotic therapy may be considered, especially if the child appears toxic or has severe symptoms. Ceftriaxone is a common choice for suspected bacterial dysentery. However, judicious use of antibiotics is crucial to prevent antibiotic resistance.
• Diet: Continue oral feeding as tolerated, avoiding lactose-containing products initially.
• Monitoring: Closely monitor vital signs (heart rate, respiratory rate, blood pressure), urine output, and clinical status for signs of deterioration.

Important Considerations: The child’s active state is reassuring, but dehydration can progress rapidly in young children. Frequent reassessment is crucial. If there is suspicion of intussusception, further investigation and potential intervention (e.g., air enema or surgical reduction) may be required.