Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS) is a medical condition affecting children who experience a sudden and dramatic onset of neuropsychiatric symptoms. This disorder is triggered by an immune system response to a Group A Streptococcus (GAS) infection. This article explores the underlying mechanism, symptom presentation, diagnosis, and treatment strategies available to manage the condition.
Defining PANDAS
PANDAS is a post-infectious autoimmune disorder that specifically follows an infection by Group A Streptococcus bacteria, such as strep throat or scarlet fever. The mechanism involves molecular mimicry, where the immune system creates antibodies to fight the bacteria but mistakenly produces autoantibodies that cross-react with healthy tissue. These misdirected antibodies target the basal ganglia, a brain area responsible for regulating movement, emotion, and behavior.
The resulting inflammation in the basal ganglia leads to the abrupt and severe neuropsychiatric symptoms characteristic of the disorder. PANDAS is a specific subtype of Pediatric Acute-onset Neuropsychiatric Syndrome (PANS). PANS includes all cases of acute-onset symptoms regardless of the trigger, but PANDAS is reserved exclusively for those cases where the trigger is confirmed to be a streptococcal infection.
Distinctive Symptom Presentation
The defining feature of PANDAS is the acute, dramatic onset of symptoms, often described by parents as occurring “overnight.” Hallmark symptoms involve the sudden appearance or severe worsening of Obsessive Compulsive Disorder (OCD) and/or tics. These new symptoms can be functionally debilitating, causing a complete disruption to the child’s life and ability to function.
These primary symptoms are often accompanied by other acute neuropsychiatric issues that appear simultaneously. Children may exhibit severe separation anxiety or experience extreme emotional lability, characterized by rapid mood swings, irritability, and rage episodes. Behavioral regression is also common, where a child loses age-appropriate skills, such as returning to baby talk or experiencing a sudden onset of bedwetting or frequent urination.
Motor and sensory difficulties frequently manifest during a symptom flare-up. An abrupt deterioration in fine motor skills, particularly handwriting (dysgraphia), is a specific sign often observed. Other symptoms can include:
- Sensitivity to light or sound
- Sleep disturbances
- Motoric hyperactivity (restlessness)
- Unusual, small, jerky movements known as choreiform movements
These episodes often follow a relapsing-remitting course, returning with subsequent strep exposure.
Diagnostic Criteria and Process
PANDAS is a clinical diagnosis based on five specific criteria established by the National Institute of Mental Health (NIMH). The first criterion requires the presence of clinically significant obsessions, compulsions, or both tics and obsessions/compulsions, which must be severe enough to impair daily function. The second criterion is an unusually abrupt and dramatic onset of symptoms, typically followed by an episodic or relapsing-remitting course.
The third requirement specifies that the onset of symptoms must occur in childhood, between three years of age and puberty. The fourth criterion necessitates a clear association with a Group A Streptococcal (GAS) infection, which can be confirmed by a recent positive throat culture or elevated anti-streptococcal antibody titers. Blood tests, such as the Anti-Streptolysin O (ASO) and anti-DNase B titers, are used to provide evidence of a recent or past strep infection.
Finally, the diagnosis requires an association with neurological abnormalities, especially during symptom exacerbations. These can include motoric hyperactivity or the presence of adventitious movements, such as the small, involuntary choreiform movements. The diagnosis is made by a physician who carefully evaluates the child’s clinical presentation and medical history against all five of these defined criteria.
Treatment Approaches
Treatment for PANDAS is multifaceted, involving therapies aimed at three main targets: the infection, the autoimmune response, and the psychiatric symptoms. The immediate first step is to address any existing streptococcal infection using antibiotics to eradicate the bacteria. Eliminating the trigger is necessary to prevent the immune system from continuing its misdirected attack.
For moderate to severe cases, specialized immunomodulatory treatments may be used to calm the overactive immune system. These therapies, such as Intravenous Immunoglobulin (IVIG) or plasma exchange (plasmapheresis), work to reduce autoantibodies or modulate the immune response causing brain inflammation. Corticosteroids may also be used temporarily to quickly reduce severe inflammation and alleviate acute symptoms.
Once the infection and inflammation are under control, ongoing management focuses on treating the resulting psychiatric symptoms. Standard psychiatric interventions, including Cognitive Behavioral Therapy (CBT), are employed to manage obsessive-compulsive behaviors and anxiety. Psychotropic medications, such as selective serotonin reuptake inhibitors (SSRIs), are commonly used to help manage anxiety and mood symptoms that persist.