Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) Syndrome: A 10-Year Retrospective Cohort Study in an Italian Centre of Pediatric Rheumatology

Abstract

Background: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) syndrome is a rare pediatric disorder consisting of a sudden onset of obsessive-compulsive disorder (OCD) and/or tics after a group A Streptococcus (GAS) infection.

Methods: In the period between 2013 and 2023, 61 children presented to our Pediatric Rheumatology unit with a suspicion of PANDAS syndrome. Among these, a retrospective analysis was conducted, and 19 fulfilled the current classification criteria and were included in this study.

Results: The male-to-female ratio was 14:5, the median age at onset was 7.0 (2.0-9.5) years, and the median age at diagnosis was 8.0 (3.0-10.4) years. The median follow-up period was 16.0 (6.0-72.0) months. Family and personal history were relevant in 7/19 and 6/19 patients. Tics were present in all patients. Details for motor tics were retrospectively available in 18/19 patients, with the eyes (11/18) and neck/head (10/18) being most often involved. Vocal tics were documented in 8/19, behavioral changes in 10/19, and OCD in 2/19. Regarding the therapeutic response, all patients responded to amoxicillin, 12/13 to benzathine benzylpenicillin, and 7/9 to azithromycin.

Conclusions: Our findings partially overlap with previous reports. Larger prospective studies are needed to improve treatment strategies and classification criteria.

Keywords: GAS; PANDAS; PANDAS syndrome; antibiotics; pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections; streptococcus.

Figure 1

The retrospective process of inclusion of 61 children presenting to our center of Pediatric Rheumatology (created with BioRender.com). Based on the present classification criteria for PANDAS syndrome, the following patients were excluded: 5 had symptoms that appeared during or after puberty; 8 had clinical presentations that did not match the PANDAS syndrome (e.g., epilepsy, lack of tic disorder or OCD, complex patients with diagnosed neurological syndromes); 9 had an unconfirmed association with a Group A beta-hemolytic Streptococcus (GAS) infection; and 20 were lost to follow-up, resulting in the absence of a diagnosis. Thus, 19 children were ultimately diagnosed with PANDAS syndrome after a minimum of six months of follow-up.

Figure 2

Treatment response to antibiotic drugs in the cohort of 19 patients diagnosed with PANDAS syndrome (created with BioRender.com). (A) Amoxicillin: 15 patients were treated with oral amoxicillin (50 mg/kg/day for 7–10 days), 14/15 as first-line treatment. All patients showed a good improvement; specifically, 12/15 had a partial response and 3/15 had a complete response. (B) Benzathine benzylpenicillin: 13 patients were treated with intramuscular benzathine benzylpenicillin (600,000 UI in children with less than 27 kg, 1,200,000 UI in children with more than 27 kg, every 21–28 days) for a median time of 14 months (1.0–82.0). A total of 4/15 were treated with benzathine benzylpenicillin as first-line treatments. A total of 12/13 showed a good improvement; specifically, 10/13 had a complete response and 2/13 had a partial response. A patient did not respond. (C) Azithromycin: 9 patients were treated with oral azithromycin (10 mg/kg/day for 3 days). A child was treated with azithromycin as first-line treatment with no response. A total of 7 patients showed a good improvement; specifically, 2/9 had a complete response and 5/9 had a partial response.