What are the next steps for a child with PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections), who experienced a recurrence of OCD (Obsessive-Compulsive Disorder) and intrusive thoughts after an initial improvement with a 5-day course of prednisone?

Management of PANDAS Recurrence After Initial Steroid Response

For a child with PANDAS who had initial improvement with prednisone but is now experiencing recurrence of OCD and intrusive thoughts, the next treatment step should be immunomodulatory therapy with intravenous immunoglobulin (IVIG) combined with cognitive-behavioral therapy (CBT) focusing on exposure and response prevention (ERP).

Understanding the Current Situation

Your daughter's presentation shows a classic pattern of PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections):

• Initial trigger by streptococcal infection
• Development of OCD and intrusive thoughts
• Partial response to antibiotics
• Significant improvement with corticosteroids (prednisone)
• Symptom recurrence after steroid discontinuation

This pattern strongly suggests an autoimmune mechanism, where the initial streptococcal infection triggered an immune response affecting brain function 1.

Treatment Algorithm for Recurrent PANDAS

First-line interventions (already tried):

• Antibiotics for acute streptococcal infection
• Short-course corticosteroids (prednisone)

Next steps for recurrence (in order of priority):

1. Immunomodulatory therapy

   • IVIG is the most evidence-supported immunomodulatory treatment for PANDAS with recurring symptoms despite standard treatments 2
   • Typical dosing is 1-2 g/kg divided over 2 days
   • May require multiple courses in some cases

2. Cognitive-behavioral therapy (CBT)

   • CBT with exposure and response prevention (ERP) has shown effectiveness specifically for PANDAS-related OCD 3
   • Should be implemented concurrently with immunomodulatory treatment
   • Involves gradual exposure to fear-provoking stimuli while preventing compulsive responses

3. Longer-term antibiotic prophylaxis

   • Consider prophylactic antibiotics to prevent future streptococcal infections
   • Though controversial, may be beneficial in preventing recurrences in selected cases 1

4. SSRI medication

   • If symptoms persist despite above interventions, adding an SSRI may help manage OCD symptoms
   • Should be used as an adjunct to immunomodulatory therapy and CBT, not as a replacement

Important Clinical Considerations

• Confirm ongoing immune activation: Consider testing for anti-streptococcal antibodies (ASO, anti-DNase B) to document ongoing immune response
• Rule out new infections: Check for occult streptococcal infections that might be triggering the recurrence
• Monitor neurological symptoms: Watch for choreiform movements or other neurological abnormalities that might indicate progression

Potential Pitfalls to Avoid

1. Undertreatment: Using only standard OCD treatments without addressing the autoimmune component can lead to prolonged symptoms and potentially more difficult-to-treat disease 1

2. Overdiagnosis: Not all cases of OCD with concurrent streptococcal infection represent PANDAS. The temporal relationship and sudden symptom onset are critical diagnostic features 1

3. Delayed treatment: The autoimmune process can become more entrenched over time, making treatment more difficult. Prompt intervention during exacerbations is important 4

4. Ignoring psychological components: Even with an autoimmune etiology, the psychological aspects of OCD require specific treatment through CBT/ERP 5, 3

While there remains some controversy around PANDAS treatment, the recurrence of symptoms after initial steroid response strongly suggests an immune-mediated process that would benefit from more definitive immunomodulatory therapy combined with evidence-based psychological treatment.