Can an infection suddenly cause OCD?


Clinical Instructor in Psychology, Harvard Medical School

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Consider this scenario: You are the parent of a six year-old child. He recently had strep throat, but is feeling better. One morning, his screaming wakes you up. You can’t calm him down or completely follow what he is talking about, but it has something to do with germs and fear and danger. The morning is consumed with attempts to comfort him and try to understand what is going on. Getting to school isn’t an option, which is highly unusual for him. Over the next few days, it gets worse. He washes his hands until they bleed, and refuses to eat because he says the food is contaminated.

It’s possible that his strep infection triggered sudden-onset obsessive compulsive disorder (OCD). Quick treatment with antibiotics can reverse the problem.

Infectious disease and mental health experts call this pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS for short). This controversial and seemingly rare diagnosis was given to children who abruptly developed obsessive compulsive disorder or tic disorders such as Tourette’s syndrome after contracting infections caused by group A streptococcus bacteria, such as strep throat or scarlet fever.

The first cases of PANDAS were described in 1998. Since then, experts have recognized that other infectious organisms besides group A streptococcus bacteria can cause sudden-onset OCD or tics. In a paper published last week in the medical journal Pediatrics & Therapeutics, Dr. Susan Swedo and her colleagues detailed this new understanding and recommended creating a more comprehensive diagnosis: pediatric acute-onset neuropsychiatric syndrome (PANS). Dr. Swedo is Chief of the Pediatrics and Developmental Neuroscience Branch at the U.S. National Institute of Mental Health.

How can an infection do this?

What we think is happening to these children is that antibodies to the infectious agent cross the barrier that protects the brain from what’s circulating in the bloodstream. Once inside the brain, the antibodies inflame a structure called the basal ganglia. The basal ganglia controls various functions, including fine motor movements (like handwriting), thinking, emotion, and learning routine behaviors or habits. It may also play a role in the development of OCD.

Recognizing PANS

The vast majority of children get through a strep or other infection without any long-term complications. Still, it’s good to know the warning signs of PANS. They include sudden

  • Onset of OCD (seemingly overnight preoccupation with germs, hand washing, counting, repeating, etc.)
  • Challenges with eating, or refusing to eat
  • Sensitivity to clothes, sound, light, or other stimuli
  • Worsening of handwriting
  • Bedwetting or change in urinary frequency
  • Appearance of tics
  • Easy distractibility, inability to focus or pay attention, or problems with memory
  • Anxiety or panic attacks over things that were no big deal a few days ago, such as thunderstorms or bugs
  • Inability to separate from a caregiver or to sleep alone

If your child suddenly shows any of these symptoms, call your doctor as soon as you can. Then contact the International OCD Foundation to find an OCD specialist in your area. Early treatment may prevent life-long mental illness.

Sounding a warning

With evidence mounting about the connection between infection and sudden-onset OCD, as the executive director of the International OCD Foundation I helped coordinate two new public service announcements to help raise awareness that OCD and tic disorders can be triggered by infections in children. For many of these children, quick treatment with antibiotics can be the key to reversing OCD, tics, and other symptoms.

At the International OCD Foundation, we have heard heart-wrenching stories of well-adjusted children who develop sudden onset OCD. I have seen chilling before and after videos. One clip, with a time stamp of August 10, 2010, shows a typical, happy go lucky kid. The next clip, dated August 12, 2010, shows a screaming, terrified child and bewildered parents.

Handwriting samples also tell a story. As the infection interferes with the activities of the basal ganglia, there’s a deterioration of fine motor coordination, and thus handwriting. Here is an example of the change in writing and drawing skills in one youngster:

Image courtesy of Susan E. Swedo, James F. Leckman, and Noel R. Rose from their paper: From Research Subgroup to Clinical Syndrome: Modifying the PANDAS Criteria to Describe PANS (Pediatric Acute-onset Neuropsychiatric Syndrome). Pediatrics & Therapeutics 2:113. doi:10.4172/2161-0665.1000113

Jeff Szymanski, PhD, is the executive director of the International OCD Foundation in Boston, a clinical instructor in psychology at Harvard Medical School, and author of The Perfectionist’s Handbook (Wiley, 2011).

Related Information: Coping with Anxiety and Phobias


  1. kristiene

    My son was diagnosed with Aspergers Syndrome in August of 2008. Since then I have been on a mission to learn all that I can about this challenge he has. I really hate using the term disability because, in my opinion, he is just different – not disabled. There has been a lot of discussion lately about whether to do away with the term Aspergers Syndrome and just use the Autism diagnosis instead. There are pros and cons to both but I am leaning towards no.
    Aspergers is considered by many as high functioning Autism although they are really very different. While they both fall on the Pervasive Development Disorder (PDD) scale, they have some vast differences. Typically, Autistic people do not want to socialize while Asperger’s (Aspies) do want to be social but they just don’t have social skills. One of the other differences in the language delay, those with Autism are typically delayed in developing language skills while Aspies are not.

  2. RM

    PANDAS and autism is very common. My son has both. When we can get his PANDAS under control, his autism is almost nonexistant. He has been diagnosed with PDD-NOS, which is atypical autism. PANDAS antibodies can also attack other areas of the brain if the infection gets out of control. People need to be aware of this. Untreated strep would result in my son regressing further into autism. If you have looked into Saving Sammy, you’ll notice he stopped responding, like many autistics, and that some of his repetitive behaviors could be considered similar to stimming.
    With my son, he also gets repetitive movements and OCD, but ADHD symptoms, major defiance and extreme outbursts, threats of violence, etc.
    More doctors of autistic kids need to screen them for PANDAS.

  3. Tami Fraser

    Dr Syzmanski, I noted that your article, like the IOCD foundation’s article, failed to mention that children with autism get PANDAS/PANS. When children with autism, after the 12-24 month regression, are coming along well, making great gains, then regress again, and again- this is PANS. Practitioners are throwing our children out, claiming it’s just autism. Nothing oould be farther from the truth. Sue Swedo has even said children with autism are very likely to get PANDAS (now PANS). As you know, there is nothing in the DSM to excuse repeated regressions with the exact same symptoms of PANS by brushing it off as “just autism”. We need the experts to speak up on our behalf, because pediatricians and “tic” specialists are ignoring signs of PANS in our kids. Please give parents a hand by putting this in print.

  4. Kate

    Tics can be the primary symptom.
    I’m a mother of 3 that tic.
    Two are in remission.
    One has had MANY episodes and a long time before a Dr would treat him. His is more chronic at this point.

  5. dad of 7 yr old

    my son had tubes in ears early on and is succeptible to allergies and was taking nasonex his doctors do not believe his ocd is panda related I have demanded the tests

  6. Mom of OCD teenager

    My daughter was exhibited signs of OCD when he was 15 years old. She had a history of chronic sinus infections and ear infections. She was tested for the strep by the psychiatrist but nothing showed. I find it very interesting that other infectious organisms beside the strep cause the OCD. She is very allergic and I definitely believe that the OCD may very well be an autoimmune response to the many allergens she confronts and the many sinus/ear infections she endured which were treated with 500-775 mg of Augmentin. She has been taking 80 mg of Prozac daily for the past seven years. Her OCD is under control however she does have some anxiety issues. She is a college graduate and has a masters degree. She is employed at a reputable financial firm.

  7. Deborah H Lowe

    In July 2009 this is exactly….what happened to our daughter then age 8. Being an RN myself I quickly pushed and sought medical treatment. NO MD was willing to hear when I suggested this was PANDAS. i just thank GOD I pursued, threatening to travel to Mexico to obtain antibiotics. In short, she got the antibiotics but i felt like she need IVIG, so I then traveled to Chicago, Il to have this with Dr M Kovacevic, then 12/27/12 she had Tonsils and Adenioids removed which were filled with Pseudomonas. I pushed at that time to cover her with a combo antibiotic of Keflex 500mg qday (which she takes everyday) and Augmentin 500mg BID that is twice a day 10day prior surgery and 10 days after.
    Today she is symptom free of PANDAS please feel free to contact me for any more info. I hve started a PANDAS network support group here in the Phoenix AZ area

    • Lynn Alello

      Hi Deborah,
      Thanks for the info. My 6 year old son showed extreme OCD the week of Jan 23, 2012 Back in Aug he was tested for strep results were negative. I would like more info please contact me

      • Mom of 3 boys

        The results of a strep test in the throat are OFTEN negative because the infection could have passed and now it has triggered the autoimmune issue. Ask for blood tests that look for increased strep antibodies in the blood: ASO and Anti Dnase. My son tested negative for strep but his ASO that should not have been over 170 was 1,720 and his Anti D-Nase that was not suppose to be over 200 was almost 2,000. His overnight onset was Dec. 11, 2009. Because we could not find any doctor to believe how suddend and severe this occured, he did not get quick treatment and so healing is much more difficult. This illness can change a family in the blink of an eye….

    • Vicki Fitzmaurice

      I admire your persistence in helping your daughter and it is awesome that she is symptom free. Our son has been ill for two years with PANDAS; at first we did not know what was wrong. He stopped eating, drinking and swallowing because he was afraid he would choke. This happened when he was ill with a sinus infection and strep throat in February 2010. We have been to an eating disorder insitution, an ocd hospital, and have had his sinuses and adenoids removed, but he continues to struggle; his condition is very severe. We have begun to pursue experts in the field of PANDAS. If you have any information that would be helpful and would be willing to share that I would appreciate it. I hope that some day our son can be at least some what improved.

      • Kathleen

        Our doctor is Rosario Trifiletti in New Jersey. I credit him with saving our son who contracted PANDAS in the middle of 2nd grade. You may need a stronger treatment such as IVIG to get your son on the right path. He can be very hard to reach. Other good doctors are Beth Latimer and Dan Geller. I suggest you read Beth Maloney’s Saving Sammy if you have not yet done so.
        Best of luck to you!
        Sincerely, Kathleen

    • RM

      Hi Debra,
      I too live in AZ and my 8 yr. old son was diagnosed with PANDAS almost a year ago. I don’t know anyone else out here who has a kid with PANDAS. I would like to join your support group. you can email me at

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