Strep throat, caused by the Streptococcus pyogenes bacteria, is one of the most common illnesses in school-age children. In most cases, the physician prescribes an antibiotic that quickly clears up the infection. But in one out of every 200 children, strep triggers an immune response that leads to brain inflammation. Soon after, the child abruptly develops an array of neurologic abnormalities. Pediatric autoimmune neuropsychiatric disorder associated with streptococcus (PANDAS) is a syndrome characterized by the sudden onset of behaviors, including obsessive-compulsive disorder (OCD) and personality changes following a strep infection.
Symptoms of PANDAS
Children who develop PANDAS test positive for recent streptococcal infection, like strep throat (also known as GAS pharyngitis), scarlet fever, or peri-anal strep, an infection of the skin around the anus. Within two to three days — or in some cases, overnight — the child shows signs of emotional instability, irritability, rage, sensory or motor abnormalities, sleep problems, urinary control issues, food refusal, depression, and developmental regression. He or she may also experience unwanted impulses, thoughts, and images called obsessions, which lead to anxiety. The child may lose academic abilities, including handwriting skills. If the child experienced OCD or tic symptoms before the strep infection, their symptoms become worse after developing PANDAS.
Causes of PANDAS
Researchers have studied only small populations when investigating PANDAS. Some of these studies were low-quality or produced conflicting results. The causes of the syndrome are based on theories because the medical community does not know the exact pathophysiology. Others question whether PANDAS even exists. One of the most widely accepted causal theories is that a strep infection triggers an autoimmune response, leading to PANDAS. Some researchers theorize a genetic predisposition for the syndrome, which the strep infection triggers.
Criteria for Diagnosis
Because there are so few studies about the syndrome, the medical community interprets the research in very different ways. There are no tests available to verify the syndrome. For this reason, some physicians do not consider PANDAS a diagnosis and choose to focus on treating the psychiatric symptoms. Physicians rely on a set of diagnostic criteria and blood tests to look for a previous strep infection:
- Pediatric onset of symptoms
- OCD, tic disorder, or both
- Positive throat culture for strep or a history of scarlet fever or other group A beta-hemolytic strep infection
- Neurological abnormalities, such as jerky movements or physical hyperactivity
- Abrupt onset or worsening of symptoms
Additional Behavioral Symptoms
Children experience a wide variety of other behaviors in addition to tics and OCD. Fidgeting, hyperactivity, inattention, and separation anxiety are common. Extreme mood changes include laughing or crying unexpectedly at inappropriate times. In addition to these behavioral or psychiatric symptoms, there are physical ones as well. Doctors say that increased urination during the day and a sudden onset of bedwetting at night is characteristic. Parents also report complaints of joint pain.
PANDAS Episodes
PANDAS symptoms have dramatic ups and downs. Obsessive-compulsive behaviors and tics change sporadically, appearing suddenly, worsening, then gradually improving. Symptoms may last for days, then subside for a few more. Severe symptoms could last for weeks or months at a time, however. If the child contracts another strep infection, the OCD and behavioral symptoms worsen.
Age of Onset
PANDAS is a pediatric disease. Around 69% of the children who contract it are between the ages of four and nine. Another 19% are between 10 and 13 years. However, around 11% of families report children aged one to three exhibiting OCD and tic behaviors following a strep infection. Only 1% of those with PANDAS symptoms are over the age of 14. Physicians have diagnosed more than 500,000 children in the US with OCD. Another 138,000 have Tourette syndrome. Some specialists and researchers believe that children with PANDAS make up about 25% of those diagnoses.
Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS)
Although researchers identified PANDAS as a medical syndrome a decade ago, it was classified as a subset of PANS or pediatric acute-onset neuropsychiatric syndrome more recently. Unlike PANDAS, streptococcus does not lead to PANS. The latter disorder has similar neurologic symptoms, but studies indicate links to infections and metabolic disturbances such as mycoplasma, mononucleosis, Lyme disease, and the H1N1 flu virus. Bloodwork generally shows signs of inflammation.
Sydenham’s Chorea
Another children’s neurological disorder, Sydenham’s chorea, results from group A beta-hemolytic strep infection. Children with Sydenham’s chorea experience erratic and involuntary movements of the facial muscles, trunk, and legs. The condition affects young people between five and 15 years of age, primarily girls. In some cases, the disorder strikes six months after the fever or infection clears. Like PANDAS, Sydenham’s chorea symptoms evolve rapidly.
Treatment
Depending on the type of infection, physicians may prescribe antibiotics for PANDAS. The American Academy of Pediatrics recommends that children with the condition continue taking antibiotics for at least five years after the last attack or until they are 21. Children who do not respond to antibiotics and experience severe symptoms may be prescribed plasmapheresis, which removes harmful auto-antibodies from the blood. Other treatment options include steroids, behavioral therapies, and tonsillectomies.
Prognosis
PANDA specialists say early antibiotic treatment is key. Reactions to strep infections after the age of 12 are rare. There is some speculation that PANDAS stops at the age of menses in females. However, low levels of OCD, tics, and anxiety could last for months, or in some cases, be permanent. Interviews with parents of children with the condition indicate that only about three percent continue to experience issues into adulthood, but studies are ongoing. Researchers theorize that the child’s immune system will eventually develop the correct antibody response to strep.