The typical symptoms of OCD—in which a child looks to manage unwanted thoughts or impulses through repetitive rituals such as hand washing and touching things in a certain order—normally come on gradually. But with acute-onset OCD, parents report that symptoms appear “overnight.” There is debate in the medical community over what causes acute-onset OCD and how to treat it.

While researchers originally hypothesized that the symptoms were triggered by a strep infection, hence the name PANDAS, it later became linked to other types of infections, such as Lyme disease, mononucleosis and the flu. The more recent name, PANS, doesn’t specifically link the condition to any cause.

Symptoms of PANDAS or PANS

Treatment for PANDAS and PANS

How acute-onset OCD is treated depends on the clinician’s belief as to the cause. If it’s linked to an infection, treatment involves targeting the inciting infection with antibiotics; in severe cases, treatment options include plasmapheresis (the exchange of blood plasma) or IVIG (intravenous immunoglobin), which gives children antibodies from a myriad of donors.

Clinicians who do not accept infection as a cause usually recommend the standard treatments for OCD, including exposure therapy and antidepressant medication.