How should a pediatric patient with acute diarrhoea and fever be evaluated and treated?

Evaluation and Treatment of Pediatric Diarrhea with Fever

Assess dehydration severity immediately using clinical signs, initiate oral rehydration solution (ORS) as first-line treatment for mild-to-moderate dehydration, continue age-appropriate feeding without delay, and avoid antimotility agents entirely in children. 1, 2

Initial Clinical Assessment

Rule Out Non-Gastrointestinal Causes

Fever, vomiting, and loose stools can indicate serious non-GI illnesses that require immediate attention: 1

• Meningitis, bacterial sepsis, pneumonia, otitis media, and urinary tract infection must be excluded through focused history and physical examination 1
• Auscultate for adequate bowel sounds before initiating oral therapy 1
• Obtain accurate body weight for fluid deficit calculation 1

Categorize Dehydration Severity

Use clinical signs to determine fluid deficit percentage: 1, 2

Mild dehydration (3-5% fluid deficit): 1, 2

• Increased thirst
• Slightly dry mucous membranes

Moderate dehydration (6-9% fluid deficit): 1, 2

• Loss of skin turgor with tenting when pinched
• Dry mucous membranes
• Decreased urine output

Severe dehydration (≥10% fluid deficit): 1, 2

• Severe lethargy or altered consciousness
• Prolonged skin tenting >2 seconds
• Cool, poorly perfused extremities with decreased capillary refill
• Rapid, deep breathing (indicating acidosis)
• Signs of shock

Key clinical pearl: Prolonged skin retraction time, abnormal capillary refill, and rapid deep breathing are more reliable predictors of significant dehydration than sunken fontanelle or absent tears. 1, 3

Laboratory Testing

Stool cultures are indicated only for: 1

• Bloody diarrhea (dysentery)
• Suspected bacterial infection with fever and systemic toxicity

Serum electrolytes should be measured when: 1

• Clinical signs suggest abnormal sodium or potassium concentrations
• Severe dehydration is present

Routine stool testing is NOT needed when viral gastroenteritis is the likely diagnosis in mild illness. 4

Treatment Algorithm

For Mild Dehydration (3-5% deficit)

Administer 50 mL/kg ORS over 2-4 hours: 2, 5

• Use small, frequent volumes (5-10 mL every 1-2 minutes via spoon or syringe) to prevent triggering vomiting 3
• Gradually increase volume as tolerated 3
• Replace ongoing losses continuously 1

Continue breastfeeding immediately without interruption throughout rehydration. 2, 5

Resume age-appropriate diet as soon as rehydration is achieved: 1, 2

• Early refeeding (within 4-6 hours) reduces illness severity and duration 1, 3
• Offer starches, cereals, soup, yogurt, vegetables, and fresh fruits 3
• The BRAT diet has limited supporting evidence but is not harmful 1

For Moderate Dehydration (6-9% deficit)

Administer 100 mL/kg ORS over 2-4 hours: 2

• Continue small, frequent volumes initially 3
• Monitor vital signs, capillary refill, skin turgor, mental status, and mucous membrane moisture every 2-4 hours 2, 3

Consider ondansetron (0.15 mg/kg orally) if vomiting prevents adequate ORS intake: 1, 3

• Facilitates oral rehydration tolerance in children >4 years 1
• Reduces immediate need for hospitalization or IV rehydration 1
• May increase stool volume as a side effect 1

Resume feeding immediately after rehydration is achieved. 1, 2

For Severe Dehydration (≥10% deficit)

Immediate IV isotonic fluids (lactated Ringer's or normal saline) at 20 mL/kg over 30 minutes: 3

• Hospitalization is required 3, 5
• Reassess after bolus and repeat if signs of shock persist 3
• Transition to ORS once patient can tolerate oral intake 2

Medications: What to Use and What to Avoid

CONTRAINDICATED in Children

Loperamide and other antimotility agents are absolutely contraindicated in children <18 years: 1, 3, 5

• Serious side effects include ileus, drowsiness, abdominal distention, and potentially fatal complications 1, 3
• Six of 28 patients in one controlled study experienced side effects requiring discontinuation 1

Avoid in ALL ages with fever or bloody diarrhea due to risk of toxic megacolon. 1

Appropriate Adjunctive Therapy

Ondansetron may be used in children >4 years with significant vomiting: 1, 3

• Dose: 0.15 mg/kg orally 3
• Facilitates ORS tolerance 1, 3
• Does not decrease hospitalization rates at 72 hours post-discharge 1

Antibiotics are NOT indicated for viral gastroenteritis and provide no benefit while potentially causing harm. 5

Red Flags Requiring Hospitalization

Admit to hospital if any of the following are present: 3, 5

• Severe dehydration requiring IV fluids
• Failure of oral rehydration therapy despite ondansetron trial
• Altered mental status or signs of shock
• Absent bowel sounds (ileus)
• Bloody stools with fever and systemic toxicity
• Persistent vomiting preventing adequate oral intake

Special Populations

Infants <6 months: 2

• Higher risk of severe dehydration
• Lower threshold for hospitalization
• Continue breastfeeding throughout illness

Infants fed human milk: 2

• Loose "pasty" stools are normal and should not be classified as diarrhea
• Diarrhea is defined as ≥3 loose/liquid stools in 24 hours OR frequency exceeding the infant's usual pattern

Common Pitfalls to Avoid

Do not delay feeding for 24 hours – this outdated practice does not improve outcomes and worsens nutritional status. 1

Do not rely on antimotility agents as a substitute for proper fluid and electrolyte therapy. 1

Do not routinely use antibiotics – most pediatric diarrhea is viral (norovirus 58%, rotavirus previously most common). 2

Do not use metoclopramide in children with acute diarrhea. 2