No, I am not writing a veterinary piece this week on zoo animals. I am referring to Pediatric Autoimmune Neuropsychiatric Disorders related to Streptococal infections. PANDAS is a well-known acronym in the medical world for several decades, yet a still mysterious constellation of symptoms with even more mysterious mechanism by which it wrecks havoc in many children and families.
PANDAS grew out of work with Rheumatic Fever and Sydenham’s Chorea. These two older diagnoses are diseases which may follow acute strep infections such as strep throat. Rheumatic Fever would damage the heart and joints of children after a strep throat infection and led to the practice of prompt antibiotic therapy for such sore throats. The percentage of children that progress beyond a simple strep throat is not very high, and may even be decreasing. Still, the disease is always in the back of doctor’s minds as they treat children’s sore throats. Sydenham’s chorea, similarly, follows strep infections, but rather than targeting the heart or joints, it produces neurologic changes. Abnormal movements called chorea result.
Obviously from these two disease, strep infections cause more problems than sore throats and skin infections, but not necessarily through infecting these organs. The mechanism appears to be the cross reaction of antibodies aimed at the strep bacteria with our own tissues. These antibodies are produced in order to kill the bacteria. The problem arises when the antibodies also attach to proteins of our own tissues which look like the bacterial proteins. Then our tissue gets caught up in inflammation and attempted destruction.
In PANDAS, this cross reaction attacks nerve cells in the brain and produces symptoms like tics, obsessive compulsive symptoms, and other odd symptoms. Tics are repetitive movements that the patient cannot control. Sometimes they are simple twitches, but can even be uncontrolled episodic cursing and other complex behaviors. Depending on their intensity, they can interfere severely with life. The obsessive compulsive aspect means that the patient experiences recurrent urges to perform certain actions. This may be repetitive hand washing for fear of being dirty or could be the need to repeatedly check that a light or appliance was turned off. We all recheck such things occasionally in our daily routine, but these patients do so over and over until they cause problems for daily life. Their actions are very disruptive to themselves and sometimes to others in the family.
In PANDAS, these patterns develop quite suddenly after a strep infection. Rather than build slowly, they burst into a child’s life out of nowhere after the infection. These patterns often last for many months before the child receives a diagnosis of PANDAS. One would hope that the diagnosis would lead to a quick cure of such a disabling disease, but alas, it is not that simple. While the children often respond well in the short run to anti-strep antibiotics, in the longer run they experience recurrences with a next strep infection. Furthermore, the symptoms often worsen with each strep infection.
Several other therapies are being used and researched in the battle against PANDAS. God willing, we will see studies coming out showing efficacy of such therapies, but for now we depend more on anecdotal reports of success. IVIG and plasmapheresis are two of these more aggressive therapies. They are often reserved for antibiotic failures since they have a higher chance of side effects. IVIG involves the IV infusion of antibodies collected from other people and concentrated for use in this product. It likely works by binding up these dangerous antibodies. The plasmapheresis involves the filtering out of the harmful antibodies from the patient’s blood. Expense and side effects are greater in each of these therapies, but after antibiotic failures, these are the main options left.