Your daughter has a sore throat and fever, and you think nothing of it--why, your son had the same thing the week before. Your son breaks out in a rash and develops scarlet fever. You take him to the doctor for antibiotics--seems he had had a streptococcal (strep) throat infection.
But something unusual happens with your daughter. She begins to have periods of trembling, and funny little movements of her arms and legs. Then she begins to act fearful about things, saying bad germs are everywhere, and that she has to wash her hands every time she touches a doorknob to get rid of them.
What's going on?
Researchers have in the past few years identified your daughter's symptoms as Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS). Your daughter has all the PANDAS hallmarks:
- it occurs in childhood, before puberty
- it starts suddenly
- there is a movement or tic disorder involved; in her case, Sydenham chorea, but it could also be Tourette syndrome
- childhood obsessive-compulsive disorder (OCD) is present (her fears and compulsive washing behavior to fight the fear)
- there was a probably streptococcal infection (specifically, group A beta-hemolytic strep, or GABHS).
The surprise culprit
In susceptible children, strep infection triggers an autoimmune response. The child's body produces antibodies to strep, as in everyone else, but these particular antibodies attack not only the strep bacteria but normal cells as well. In rheumatic fever, the heart is attacked; in Sydenham chorea, the brain is the target. These same brain cells, the basal ganglia, produce the OCD symptoms. Researchers have long known that Sydenham chorea and OCD frequently occurred together, but it wasn't until in the past few years that they realized that strep infection was at the root of both problems.
New links to strep?
Researchers testing children with OCD have found that perhaps 25% of them have antibodies to strep, meaning that they were once infected. Another interesting link is that although the incidence of Tourette syndrome (a movement disorder) in the general population is around 0.03 percent, in children with OCD the rate is 15 percent. Forty to sixty percent of children with Tourette's have OCD. Research indicates that about 10 percent of those children (with both Tourette's and OCD) have clear evidence of a streptococcal trigger.
It seems, then, that testing children who have OCD, and especially those with OCD and Tourette's, for previous strep infections could lead to those disorders being reduced or even eliminated by simply administering antibiotics. Further research is needed to clarify this and identify those children who would most benefit from treatment.
Sources:
- Osborn, Ian. "Autoimmune Neurological Disorders." Tormenting Thoughts and Secret Rituals (1999) 183-185. 28 Feb 2007 <http://hope4ocd.com/autoimmune.php>.
- Rosenbaum, J.F. "New issues in the diagnosis and treatment of anxiety disorders." 1999 American Psychiatric Association Annual Meeting (1999).
- Trifiletti, R. R., and A.M. Packard. "Immune mechanisms in pediatric neuropsychiatric disorders: Tourette's syndrome, OCD, and PANDAS." Child Adolesc Psychiatr Clin N Am 8(1999): 767-775.
