PANDAS: The Infection
Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infection (PANDAS) remains controversial in medical circles. A family requested an article about this condition, so I am sharing a story and following up with information.
Group A Strep Infection usually has 3 of the following: fever, sore throat, ABSENCE of runny nose or cough, and abdominal pain. Examination reveals a “fire-engine” red throat, swollen tonsils often with pus, a classic smell to the breath, and swollen lymph nodes. I do NOT swab every child with a sore throat who walks through my door for a reason, which is crucial for parents to understand.
Distinguishing between infection and the carrier state is important to avoid antibiotic overuse. Carriers are children whose tonsils have receptors that “like” strep bacteria but are not causing infection. Streptococcal bacteria live in their throats and are part of their normal bacterial milieu. When these kids have cold symptoms and a sore throat, some physicians do a strep test and it will be positive. These children actually DO NOT have Strep throat infection. The ‘infection’ needs treatment with antibiotics, the ‘carrier’ with a cold, needs warm drinks with lemon and honey and rest until symptoms improve.
A decade ago, at the age of 6, a young boy came in with a strep throat infection, and his story has convinced me PANDAS likely does exist. Normally, he had a happy-go-lucky demeanor; instead, he was sobbing uncontrollably and seemed like a completely different child. He had that characteristic ‘strep’ smell on exam and a strongly positive strep test, was treated with Amoxicillin, and returned in 10 days for follow up. Repeat test was negative and he was back to normal as if nothing ever happened. I did not think about this episode until 2 years later.
At 8, he had a sore throat, fever, and was inconsolable, which was remarkably uncharacteristic for him. He had the usual examination signs and I remember thinking “could this be strep again?” He had another swab done and sure enough, a strong positive result. I treated him with antibiotics, and he returned 10 days later with a negative repeat test and upbeat mood. This cycle has repeated itself 3 more times over the last 10 years. Today, he is 18 and I could diagnose Group A Strep infection without even examining him, because his demeanor changes so drastically each time. Interestingly enough, he has had influenza, mononucleosis, and a variety of other illnesses, always while maintaining his composure.
PANDAS is thought to occur when a streptococcal infection triggers a misdirected immune response resulting in significant mood and behavior changes. The child quickly begins exhibiting symptoms of OCD, anxiety, tics, personality changes, and sensory sensitivities. The diagnosis of PANDAS is clinical, which means there are no lab tests confirm its existence. These diagnostic criteria were developed:
1. Presence of obsessive-compulsive disorder and/or a tic disorder.
2. Abrupt onset and varying symptom severity
3. Neurological abnormalities (physical hyperactivity, or unusual, jerky movements that are not in the child’s control) as well as anxiety, emotional lability, or personality changes.
4. Onset of symptoms usually occur from age 3 years to puberty
5. Diagnosis of group A beta-hemolytic streptococcal infection (the bacteria that causes strep throat) either by culture or other evidence of infection, such as scarlet fever
Once the body recognizes infection with Strep bacteria, the immune system produces antibodies. Strep bacteria put molecules on its cells that look identical to those on a child’s heart, joints, skin, and kidneys, known as “molecular mimicry.” Due to this, the antibodies react with both the strep molecules and the human molecules in the heart, joints, skin, and kidneys that were mimicked. These “cross-reactive” antibodies misfire and attack the copied molecules in the child’s tissues. Studies have shown these cross-reactive antibodies may also target the brain, possibly causing OCD, tics, and the other symptoms of PANDAS.
For acute episodes of PANDAS, if the throat culture is positive, a single course of antibiotics is the best treatment and usually the symptoms subside. Sometimes, the symptoms are slow to resolve and herein lies the difficulty of treating this condition. It is possible that once the immune cascade is triggered, antibiotics alone may not fix the problem. Sometimes, a short course of oral steroids help suppress the immune response. Finally, Intravenous Immunoglobulin (IVIG) has been used, but it is a pooled blood product and I do not have enough (or any) experience to render an opinion either way.
A lot remains to be learned about neurological effects of childhood infections. Children with pre-existing tic disorders clearly have temporary worsening of tics while infected with strep bacteria. They do not necessarily have PANDAS, but it lends legitimacy to the theory.
We must use strict criteria for diagnosis and treatment. As you can see above, things are not always so simple. Many parents are convinced their child has PANDAS because they have developed ADHD or tic symptoms but before diagnosing your child, please talk to your pediatrician or find someone who knows about this condition and can evaluate your child properly.