What is the diagnosis and treatment approach for a pediatric patient with a history of streptococcal infections and symptoms of obsessive-compulsive disorder, anxiety, or tics, suspected of having Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS)?

PANDAS: Diagnosis and Treatment

Critical Context

PANDAS remains a controversial and unproven hypothesis according to the American Heart Association, and should be approached with significant clinical caution. 1, 2, 3

Diagnostic Approach

Essential Clinical Criteria (All 5 Must Be Present)

The diagnosis requires simultaneous fulfillment of all five criteria 3:

• Presence of OCD and/or tic disorder (not just behavioral problems like tantrums or screaming) 3
• Prepubertal onset of symptoms 3
• Abrupt symptom onset or episodic course (distinguishing it from gradual-onset classic OCD) 2, 3
• Temporal association with Group A Streptococcal (GAS) infection 3
• Associated neurological abnormalities, particularly choreiform movements 3

Laboratory Testing Strategy

Obtain anti-streptolysin O (ASO) titer and anti-DNase B titer to document recent strep exposure, but interpret these using age-appropriate reference ranges since school-age children normally have higher levels than adults 1, 3. Elevated titers alone do not confirm PANDAS without meeting all clinical criteria 3.

Perform throat culture only if the patient has throat symptoms 1. The American Heart Association explicitly recommends against routine laboratory screening for GAS solely to diagnose PANDAS 2, 3.

Critical Diagnostic Pitfalls to Avoid

• Do not diagnose based on antibody titers alone - elevated titers are common in school-age children and mean nothing without the complete clinical picture 3
• Do not misinterpret nonspecific behavioral symptoms (screaming, crying, tantrums) as PANDAS without the specific neuropsychiatric features (OCD, tics) and neurological abnormalities 3
• Look specifically for choreiform movements as these are key distinguishing neurological features 3

Treatment Algorithm

First-Line Treatment: Antibiotics

The initial and primary treatment is antibiotics to eradicate the streptococcal infection 1, 2:

• Penicillin V 500 mg four times daily for 10 days (preferred option) 1, 2
• Amoxicillin 500 mg three times daily for 10 days (equally effective alternative) 1, 2

For penicillin-allergic patients 1, 2:

• Erythromycin 1, 2
• Clindamycin 300 mg four times daily for 10 days (especially for eradication failures) 2
• Azithromycin (maximum 500 mg once daily for 3-5 days) 1, 2

What NOT to Do

The American Heart Association explicitly recommends against immunoregulatory therapy (IVIG, plasma exchange) as first-line or routine treatment 1, 2. Despite some research suggesting benefit, guidelines prioritize caution given the unproven nature of the diagnosis 1, 2.

The American Heart Association recommends against long-term antistreptococcal prophylaxis 2.

Post-Treatment Monitoring

Obtain post-treatment throat cultures only in patients who remain symptomatic or experience symptom recurrence 1. Do not routinely reculture asymptomatic patients.

Adjunctive Psychiatric Management

If psychotropic medications are needed, they should only be prescribed after diagnosis of a DSM-5 psychiatric disorder as part of a comprehensive treatment plan 1. For severe symptoms requiring antipsychotics, atypical agents like aripiprazole are preferred over first-generation antipsychotics due to lower extrapyramidal symptom risk 1.

Psychotherapy has shown efficacy in managing OCD symptoms and reducing stress in patients and families 4.

Broader Diagnostic Consideration

Consider PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) if the patient has sudden-onset OCD symptoms triggered by infections or insults other than streptococcal 2, 3. PANS represents a broader category with similar presentation but without the streptococcal association requirement 3.