What is the treatment for acute gastritis in children after a swimming pool bath?

Treatment of Acute Gastritis After Swimming Pool Exposure in Children

The primary treatment for acute gastritis in children after swimming pool exposure is oral rehydration therapy with low-osmolarity ORS, combined with early resumption of age-appropriate diet, while avoiding antimotility agents and unnecessary medications. 1, 2

Initial Assessment and Hydration Status

Evaluate the child's hydration status by examining specific clinical signs including skin turgor (pinch test), mucous membrane moisture, mental status, capillary refill time, and urine output to categorize dehydration severity 1, 2:

• Mild dehydration (3-5% fluid deficit): Slightly dry mucous membranes, normal mental status 1
• Moderate dehydration (6-9% fluid deficit): Loss of skin turgor with tenting, dry mucous membranes, decreased urine output 3, 1
• Severe dehydration (≥10% fluid deficit): Severe lethargy or altered consciousness, prolonged skin tenting (>2 seconds), cool extremities with poor perfusion, rapid deep breathing 3, 1

Rehydration Strategy Based on Severity

For Mild to Moderate Dehydration

Administer low-osmolarity oral rehydration solution (ORS) as first-line treatment until clinical dehydration is corrected 1, 2:

• Start with small volumes (5-10 mL) every 1-2 minutes using a spoon or syringe to prevent triggering vomiting 3
• Gradually increase volume as tolerated 3
• For moderate dehydration specifically: give 100 mL/kg ORS over 2-4 hours 3
• Replace ongoing losses: 10 mL/kg ORS for each watery stool and 2 mL/kg for each vomiting episode 3
• Reassess hydration status after 2-4 hours 3

For Severe Dehydration

Initiate intravenous isotonic fluids (lactated Ringer's or normal saline) immediately until pulse, perfusion, and mental status normalize, then transition to ORS 1, 2

Nutritional Management

Resume age-appropriate diet immediately during or after rehydration rather than restricting foods or prolonged fasting 1, 2:

• Offer starches (rice, potatoes, noodles, crackers, bananas), cereals (rice, wheat, oat), soup, yogurt, vegetables, and fresh fruits 1
• Continue breastfeeding throughout if applicable 1, 2
• Avoid foods high in simple sugars including soft drinks, undiluted apple juice, Jell-O, and presweetened cereals, as these exacerbate symptoms through osmotic effects 1
• Avoid high-fat foods as they may delay gastric emptying 1

Consideration of Milk Protein Allergy

Swimming pool-related gastroenteritis is typically viral (norovirus and astrovirus are common pool contaminants) 4, but if symptoms persist beyond expected viral course, consider milk protein sensitivity 1:

• Trial an extensively hydrolyzed protein or amino acid-based formula for 2-4 weeks in formula-fed infants if symptoms are prolonged 1
• Approximately 25% of infants with persistent gastritis symptoms may have underlying milk protein sensitivity 1

Pharmacologic Management

Antiemetic Use (If Vomiting is Prominent)

Consider ondansetron in children over 4 years to facilitate oral rehydration when vomiting is significant 1, 5, 6. For younger children with vomiting, administer small volumes of ORS (5-10 mL) every 1-2 minutes, gradually increasing as tolerated 1

Acid Suppression (If Symptoms Persist)

Use proton pump inhibitors (PPIs) or H2 receptor antagonists only if gastritis symptoms persist despite dietary modifications 1:

• Dose PPIs approximately 30 minutes before meals for optimal effectiveness 1
• Be aware that acid suppression may increase risk of community-acquired pneumonia, gastroenteritis, and candidemia in young children 1
• H2 antagonists can cause tachyphylaxis within 6 weeks with long-term use 1

Medications to AVOID

Do not use antimotility agents (loperamide) in children under 18 years, as they can cause serious side effects including ileus, drowsiness, and potentially fatal abdominal distention 3, 1, 2:

• Avoid adsorbents (kaolin-pectin), antisecretory drugs, or toxin binders, as they do not reduce symptom duration and may interfere with appropriate therapy 3, 1
• Avoid chronic antacid therapy due to associated risks in children 1

Antimicrobial Therapy Considerations

Antimicrobials have limited usefulness since viral agents (norovirus, astrovirus) predominate in swimming pool-related gastroenteritis 1, 4. Consider antimicrobial therapy only if 1:

• Bloody diarrhea is present
• Recent antibiotic use
• Immunodeficiency
• Perform stool cultures if bloody diarrhea or signs of bacterial infection are present 1

Infection Control and Prevention

Practice proper hand hygiene after using toilet, before eating, and after handling soiled items 3, 2. Swimming pool-related outbreaks can involve both norovirus and astrovirus contamination of water 4, and children are at higher risk because they swallow more water when swimming and play in shallow water which is more contaminated 7.

Common Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic testing; initiate ORS promptly 1
• Do not use inappropriate fluids like apple juice or sports drinks as primary rehydration solutions for moderate to severe dehydration 1
• Do not unnecessarily restrict diet during or after rehydration; early refeeding improves outcomes 1
• Do not rely on the "BRAT diet" exclusively (bananas, rice, applesauce, toast) for prolonged periods, as it provides inadequate energy and protein 1
• Do not use diluted formulas for extended periods, as this results in inadequate nutrition 1

Indications for Hospitalization

Reserve hospitalization for severe dehydration or shock, failure of oral rehydration therapy, altered mental status, ileus, or persistent vomiting preventing adequate oral intake 1, 2