What is the recommended treatment for oral thrush in a 9-month-old infant?

Treatment of Oral Thrush in a 9-Month-Old Infant

Oral nystatin suspension is the recommended first-line treatment for oral thrush in a 9-month-old infant at a dose of 2 mL (200,000 units) four times daily for at least 48 hours after symptoms resolve. 1, 2

First-Line Treatment: Nystatin Oral Suspension

Dosing and Administration

• For a 9-month-old infant: 2 mL (200,000 units) four times daily 1
• Administration technique:
  • Use dropper to place one-half of dose (1 mL) in each side of mouth
  • Avoid feeding for 5-10 minutes after administration
  • Continue treatment for at least 48 hours after symptoms have disappeared 1

Efficacy and Evidence

• Nystatin reduces fungal infection without systemic absorption 2
• The American Academy of Pediatrics recommends oral nystatin suspension as first-line treatment with moderate evidence quality (B-II) 2
• Treatment should continue until clinical resolution plus at least 48 hours to prevent relapse 2, 1

Second-Line Treatment: Fluconazole

Consider fluconazole if nystatin fails or in severe cases:

• Dosage: 3 mg/kg once daily for 7 days 2, 3
• Clinical evidence suggests superior efficacy compared to nystatin:
  • In a randomized study of infants, fluconazole achieved 100% clinical cure rate compared to 32% with nystatin (p<0.0001) 3
  • Another study showed 91% clinical cure with fluconazole versus 51% with nystatin in immunocompromised children (p<0.001) 4

However, fluconazole is generally reserved as second-line due to:

• Concerns about developing triazole resistance 2
• Systemic absorption (unlike nystatin which acts locally) 2
• Potential for drug interactions and side effects

Prevention of Reinfection

To prevent recurrence:

• Sterilize pacifiers and bottle nipples regularly during treatment 2
• If breastfeeding, treat mother's nipples simultaneously if they show signs of candidiasis 5
• Continue treatment for at least 48 hours after symptoms resolve 1

Treatment Monitoring and Assessment

• Assess response to therapy after 2-3 days 2
• Common reasons for treatment failure:
  • Inadequate duration of therapy
  • Poor administration technique
  • Failure to address potential sources of reinfection
  • Premature discontinuation of treatment 2

Special Considerations

If treatment fails with nystatin:

1. Reassess administration technique
2. Consider extending treatment duration
3. Consider switching to fluconazole at 3 mg/kg once daily for 7 days 3
4. Evaluate for underlying conditions that may predispose to recurrent thrush

The evidence clearly supports nystatin oral suspension as first-line therapy, with fluconazole as an effective alternative when initial therapy fails or in severe cases.