If your child changed almost overnight, suddenly gripped by fears, rituals, tics, or a refusal to eat, you are probably frightened and looking for answers. One possible explanation doctors consider is PANDAS or PANS. These are two closely related conditions in which an infection is thought to set off an immune reaction that affects the brain. What sets them apart is the speed: symptoms often start within 24 to 48 hours, as if a switch had been flipped. This guide explains what is known about the symptoms, how doctors evaluate them, which treatments have been studied, and when you should get medical help.
What Are PANDAS and PANS?
PANDAS stands for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections. It describes children who suddenly develop obsessive-compulsive disorder (OCD), tics, or both after an infection with group A strep. Susan Swedo and colleagues at the National Institute of Mental Health (NIMH) described the first 50 cases in 1998. The children’s average age was 7.3 years, and boys were affected twice as often as girls.
In 2012, the PANS Research Consortium introduced the term PANS, short for Pediatric Acute-onset Neuropsychiatric Syndrome. Many children had the same sudden symptoms but no detectable strep infection. PANS includes cases triggered by other germs.
The leading hypothesis is an autoimmune reaction called molecular mimicry. Antibodies made against strep (in PANDAS) or other germs cross-react with structures in the basal ganglia, a region deep in the brain. Proteins named as targets include tubulin and the dopamine D1 and D2 receptors.
PANDAS vs. PANS: The Key Differences
PANDAS is a subgroup of PANS. A child who meets the PANDAS criteria also meets the PANS criteria, but not the other way around.
- Trigger: PANDAS is linked only to group A strep (Streptococcus pyogenes), which can cause strep throat with scarlet fever or a throat infection without symptoms. PANS can follow many infections, including influenza, Mycoplasma pneumoniae, chickenpox (varicella), SARS-CoV-2, and Borrelia burgdorferi, the Lyme disease bacterium. Non-infectious triggers such as allergic reactions are also possible.
- Core symptom: PANDAS requires OCD and/or a tic disorder. PANS requires either OCD or a sudden, severe restriction of eating.
- Age: PANDAS by definition starts before puberty. PANS can occur at any age, including in teens and young adults.
| Feature | PANDAS | PANS |
|---|---|---|
| Trigger | Group A strep only | Many germs (e.g., influenza, Mycoplasma, SARS-CoV-2, Lyme) or non-infectious triggers such as allergic reactions |
| Age at onset | Before puberty (ages 3 to 12) | Any age |
| Required core symptom | OCD and/or tics | OCD or sudden, severe eating restriction |
| Course | Often tied to repeated strep infections | Flares with various infections |
| Relationship | Subgroup of PANS | Broader umbrella |
Recognizing the Symptoms
Sudden-onset OCD
The sudden start is what most clearly separates PANDAS and PANS from typical OCD. A child who was healthy before develops severe obsessions and compulsions within a day or two. In the NIMH research group, every child with PANDAS had an acute OCD onset, measured with the Children’s Yale-Brown Obsessive-Compulsive Scale (CY-BOCS). Common themes are fear of contamination, a need for symmetry, repeating actions, and excessive washing.
Eating restriction
For PANS, a sudden, severe restriction of food intake can take the place of OCD as the core symptom. It differs from anorexia nervosa: there is no body-image problem, it starts suddenly, and it often comes with a fear of swallowing or of being poisoned. Some children lose 5 to 10 percent of their body weight within days because they will eat only one food, such as toast or a certain brand, or nothing at all.
Tics
Motor and vocal tics occur in 60 to 65 percent of children with PANDAS. They range from simple blinking or throat clearing to complex movements. Unlike in Tourette syndrome, they start suddenly and come and go with infections. The Tourette Association of America stresses that PANDAS/PANS accounts for only a small share of Tourette cases.
Other common symptoms
- Separation anxiety: 86 to 92 percent of children
- School problems: 75 to 81 percent
- Sleep problems: 71 percent
- Frequent urination or bedwetting: 42 to 81 percent
- Handwriting changes: handwriting can get much worse within days, an early sign that teachers often notice first
- Mood changes: sudden rage, irritability, mood swings, and low mood
- Motor symptoms: restlessness, hyperactivity, and worse fine motor skills
How Doctors Diagnose PANDAS and PANS
There is no validated lab test or biomarker for PANDAS or PANS. The diagnosis is clinical and made by ruling out other causes.
For PANDAS, doctors use five criteria from Swedo and colleagues (1998):
- OCD and/or a tic disorder
- Onset before puberty (ages 3 to 12)
- Acute, dramatic onset (within 24 to 72 hours)
- A link in time to a group A strep infection
- Other neuropsychiatric symptoms alongside
For PANS (Swedo and colleagues, 2012), a child needs an abrupt onset of OCD or severely restricted eating, plus at least two of seven symptom areas: anxiety; mood swings or depression; irritability, aggression, or oppositional behavior; behavioral regression; declining school performance; sensory or motor problems; and physical symptoms such as bedwetting or sleep problems. Other causes must be ruled out.
If PANDAS is suspected, a throat swab (culture or rapid strep test) is required to confirm an active strep infection. In one study, 20 of 92 community cases (22 percent) had no documented strep infection. That ruled out PANDAS, but the children met the PANS criteria. The workup may also include blood tests (ASO and anti-DNase B titers, thyroid, ANA, iron levels) and a thorough psychiatric and neurological exam.
A screening questionnaire published in 2024 by Bleibach and colleagues in the European Journal of Paediatric Neurology has 27 items covering ten symptom areas. It was validated in 65 children and correlated well with the CY-BOCS and an ADHD rating scale (rs ≥ 0.60).
Treatment Options
Treatment is decided by your child’s doctors. The following overview explains what has been studied; it is not a treatment plan.
Antibiotics
If there is an active strep infection, the first step is a 10-day course of antibiotics, usually penicillin V or amoxicillin. In a study by Murphy and Pichichero (2002), early antibiotics led to full remission of OCD symptoms in 8 of 12 children with PANDAS. In a 30-day trial of azithromycin versus placebo in 31 children with acute OCD, more children responded to azithromycin (7 vs. 1). The PANS/PANDAS Clinical/Research Consortium, drawing on more than 1,000 patients from 17 academic centers, recommends antibiotics for all acute PANS and PANDAS cases. The Tourette Association of America, by contrast, recommends antibiotics only with a confirmed infection and a positive throat swab.
Anti-inflammatory treatment
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen are often used first and can ease symptoms in some children within 24 to 48 hours. For severe or lasting episodes, corticosteroids are used. A 2017 clinical management guideline in the Journal of Child and Adolescent Psychopharmacology recommends corticosteroids as the first immune-modulating step before IVIG and plasmapheresis.
IVIG and plasma exchange
- Intravenous immunoglobulin (IVIG): In the only randomized controlled trial of IVIG for PANDAS (Perlmutter and colleagues, 1999), OCD symptoms improved by an average of 45 percent one month after treatment, with no change under placebo. In 2025, Octapharma released results of a phase III trial of IVIG in PANS showing a statistically significant and clinically relevant improvement on the Clinical Global Impression scale.
- Therapeutic plasma exchange (plasmapheresis): In the same 1999 study, OCD symptoms improved by 58 percent within a month. Both improvements lasted at least one year. The American Society for Apheresis lists plasma exchange as a Category I first-line treatment for PANDAS and Sydenham chorea.
No treatment is FDA-approved specifically for PANDAS or PANS. According to the Cleveland Clinic, active strep infections are treated with antibiotics, and the symptoms are treated with cognitive behavioral therapy (CBT), including exposure and response prevention (ERP).
Relapses and the Long-Term Outlook
In a combined sample of 371 children with PANDAS or PANS, 167 (45 percent) had at least one flare, usually during or shortly after a viral infection. In the Murphy and Pichichero study, OCD returned within 12 months in 6 of 12 children after successful antibiotic treatment, each time with a positive strep culture.
The course differs from child to child. Some children have only one episode and stay symptom-free afterward. Others have flares with infections over several years. With early recognition and treatment, some children respond well to each episode, even though the relapsing course can last for years.
The Debate Among Experts
You may hear different views from different doctors, and that reflects a real debate. The American Academy of Pediatrics has repeatedly urged caution and says experimental treatments such as IVIG, plasma exchange, and preventive antibiotics should not be used outside clinical trials. Some studies find no significant link between strep infections and OCD or tics in children, which raises doubts about the syndrome. Supporters argue that those studies used inclusion criteria that were too broad instead of the strict NIMH criteria. Research is ongoing.
Support at School
Seventy-five to 81 percent of children with PANDAS have sudden school problems, such as falling grades, refusing to go, or separation anxiety at the school door. The International OCD Foundation recommends that you talk with the school about PANS/PANDAS, because the sudden drop in performance is part of the illness, not laziness.
The PANDAS Network offers free educator resource guides that help teachers spot sudden declines in handwriting, math, and attention. In the United States, a 504 plan can include:
- a reduced workload
- regular breaks
- movement breaks
- extended time on tests
When to Seek Help
Call your child’s pediatrician promptly if your child suddenly changes within days: new obsessions or compulsions, new tics, refusing food, rapid weight loss, or a sudden decline in handwriting. Do not wait to see whether it passes. Tell the doctor about any recent infection, such as a sore throat. Only a doctor can decide whether PANDAS, PANS, or another cause is behind the symptoms.
Seek emergency care right away if your child stops eating or drinking, or if you are worried about your child’s safety.
Frequently Asked Questions
What is PANS/PANDAS?
Both describe a sudden onset of OCD, tics, or eating restriction in children, thought to be triggered by an immune reaction after an infection. PANDAS is linked to group A strep. PANS is the broader term and includes other infections and non-infectious triggers.
What are the symptoms of PANS and PANDAS?
The hallmark is a sudden start, often within 24 to 48 hours, of OCD, tics, or severe eating restriction. Other common signs include separation anxiety, school problems, sleep problems, frequent urination or bedwetting, worse handwriting, rage, and mood swings.
What is the difference between PANS and PANDAS?
PANDAS is a subgroup of PANS. It requires a group A strep infection, onset before puberty, and OCD and/or tics. PANS can start at any age, can follow many infections or other triggers, and requires OCD or sudden eating restriction.
How is it diagnosed and treated?
There is no single blood test. Doctors use clinical criteria, a throat swab, and blood tests, and rule out other causes. Treatment options include antibiotics for a confirmed strep infection, anti-inflammatory medicine, CBT with ERP, and, in severe cases, IVIG or plasma exchange. Your child’s doctors decide which steps fit.
Does PANS/PANDAS go away?
It varies. Some children have a single episode and stay symptom-free. Others have flares with new infections over several years; in one large sample, 45 percent had at least one flare.
