PANDAS – Paediatric Autoimmune Neuropsychiatric Disorder associated with group A Streptococcus, is a condition seen in the paediatric population consisting of tics or obsessive compulsive disorder exacerbated or brought on by a common bacterial infection called Group A streptococcus (GAS). This infection may initially present with a sore throat or chest infection with the subsequent onset of neuropsychiatric symptoms (tics and obsessive compulsive behaviours).
This group of disorders has been given ICD-11 code 8E4A.0 by the World Health Organisation but despite this there is resistance to accepting it as a diagnosis by some medical practitioners in the UK. An audit done in 2018 by The Children’s e-Hospital showed that 90% of GP’s were unfamiliar with this condition.
This group of disorders is thought to occur after the body produces an antibody to fight a common everyday infection. This antibody then goes on to stimulate a part of the brain called the basal ganglia which is involved with movement control (or regulation of obsessive compulsive behaviours) and this results in the abnormal movement, feeling or compulsion that the patient experiences.
PANS (Paediatric acute-onset neuropsychiatric syndrome) describes a clinical syndrome that may be caused by noninfectious or infectious triggers. Proposed diagnostic criteria for PANS include: the sudden onset of OCD or severely restricted food intake, severe neuropsychiatric symptoms (eg, anxiety, depression, emotional lability, etc) or symptoms not better explained by a known neurologic or medical disorder. The key words in this are “sudden onset”. Symptoms appear dramatically and there is a rapid shift in the child’s behaviour.
Rheumatic fever has been a less commonly recognised condition over the past 30-40 years. Part of the diagnostic criteria for rheumatic fever included a condition called “Sydenham’s chorea” or ‘St. Vitus dance” . This was an abnormality of movement which was associated with streptococcal infection. Individuals diagnosed with rheumatic fever were given long term prophylactic penicillin to treat the condition and prevent disease relapse.
Dr Susan Swedo during her research into Sydenham’s chorea realised that there were a sub-group of patients with tics & obsessive-compulsive behaviour that had a sudden onset of symptoms. This was very different to the movements seen with rheumatic fever. Crucially the symptoms had a very rapid pace of onset.
Signs & symptoms
PANDAS symptoms typically start abruptly, almost as if a switch has been thrown. Symptoms include tics, sleep disturbance, obsessive compulsive behaviour, deterioration in handwriting, eating disorders (including anorexia but the problems appear to be more centred on difficulty in coordinating swallowing), behavioural regression and urinary incontinence. By definition these occur following a streptococcal infection which then results in the stimulation of antibodies which stimulates the part of the brain involved in movement and behaviour regulation (the basal ganglia). Examination of the child reveals a child who is “trapped” or “psychologically burdened”. They may have reduced muscle power and may show abnormal movements.
Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) is defined by the rapid onset of obsessive–compulsive disorder (OCD) or eating restrictions and comorbid symptoms from at least two of seven categories:
- Anxiety (particularly separation anxiety)
- Emotional lability or depression
- Aggression, and/or severely oppositional behaviors
- Deterioration in school performance related to ADHD-like behaviors, memory deficits, and cognitive changes
- Sensory or motor abnormalities
- Somatic signs and symptoms, including sleep disturbances, enuresis, or urinary frequency (Swedo et al. 2012; Chang et al. 2015). Acute onset cases that are triggered by Group A streptococcal infections may meet diagnostic criteria for both PANS and PANDAS.
Criteria for diagnosis of PANDAS include:
- Prescence of OCD and/or Tics
- Pre-pubertal onset
- Acute onset of symptoms with an episodic pattern
- Association with a neurological abnormality
- Temporal relationship with Group A strep infection (Determined by a raised ASO titre, Anti-DnaseB or isolation of group A streptococcus from a throat or skin swab).
Examination of the child should include looking at the throat, ears, skin (eg for impetigo or guttate psoriasis), examining the peri-anal area and genitals for infection, checking for a heart murmur and assessing weight and height.
Having the right investigations to approach the management and treatment of a child with PANDAS is essential. Our experience has shown that there is variabilty between laboratories and that using the right laboratory is important. The investigations that we recommend are available to health care professionals through our Virtual Medical School (postgraduate section). It is important to look at the child as a whole and aim to optimise the health of the child. This will include looking at conditions such as allergy.
You can download the symptom diary by clicking on the following link; PANDAS symptom monitoring chart. This scoring sheet also allows parents to add detail such as whether or not a child is receiving antibiotics or anti-inflammatories. This information is invaluable in assessing the patients that we see using the Children’s e-Hospital on-line service but can also be used to help parents with any health professionals they see.
Treatment of PANDAS
Treatment can be divided into several stages which are described below.
Induction of disease remission
- Non-steroidal anti-inflammatory drugs (eg ibuprofen). This must be used with caution in patients with asthma.
- Steroid pulse therapy (e.g. prednisolone). It is important to determine if the patient has had chicken pox previously before embarking on a prolonged course of steroids.
- Azithromycin (Zithromax)
- Penicillin V
- Co-amoxiclav (Augmentin)
- Intravenous immunoglobulin (IVIG) can be used to induce disease remission. Drs. Perlmutter and Swedo used IVIG in the 1999 study published in the Lancet where nearly all of the children benefitted from its use. The sampling was small (30 of children). In PANDAS an autoimmune irregularity is causing encephalitic-like inflammation and the use of IVIG interrupts this process. The PANDAS IVIG study (run by the PANDAS physician network) administered 1gram/kg of the child’s body weight per day on 2 consecutive days. Preliminary results were positive but not conclusive. Prophylactic antibiotics should be continued thoughout treatment if IVIG is given. Currently IVIG is in short supply in the UK and therefore this treatment is becoming more difficult to offer in the UK.
- In this process the harmful auto-antibodies are removed from the blood system itself. This procedure is not regulalrly offered in the UK.
Cognitive behaviour therapy
- The onset of PANDAS or PANS symptoms can be extremely distressing for the child and family members. It is therefore essential that psychological support with cognitive behaviour therapy (CBT) is initiated at an early stage. On-line CBT in children has been shown to be more effective than face to face therapy and also allows flexibility in seeking consultations. Using CBT gives parents the tools to manage their child during a crisis.
Once disease remission has been achieved the antibody level will gradually fall and symptoms will slowly improve unless the immune system is restimulated eg with another infection. In order to reduce the risk of further streptococcal infections, current recommendations include the use of preventative (prophylactic) antibiotics which are given long term to prevent further streptococcal infections.