What caused this child to suddenly develop tics and obsessive behaviours?

Case of the month – answers: In the latest in our series, Dr Peter Bagshaw asked readers why this child had recently developed tics and obsessive behaviours. Did you get the diagnosis? Answer revealed below!

Details of the case have been changed to ensure anonymity

Abbi is a shy eleven-year-old who recently started secondary school. She had seemed to be settling in well apart from frequent colds and sore throats.

However, her mother brought her to see the GP, concerned that for the past two weeks she had become unusually clingy, and seemed to have developed facial tics and to have become obsessive in her behaviour – for example, lining up her toys in a perfect line and becoming very fussy over food.

Her mother was concerned that she was being bullied at school, though Abbi denied this. There was no previous history of anxiety or behavioural problems, though Abbi’s father was prone to mild anxiety and depression

The GP found no other obvious abnormalities other than the tics, which consisted of frequent blinking of both eyes. He suggested Abbi was probably experiencing stress from the change of school. He considered referral to CAMHS but felt she would be unlikely to meet the criteria for acceptance, so simply reassured them both.

A week later, the mother returned in great distress. Abbi’s mental health had deteriorated dramatically. She was now sleeping in her parents’ bed because of horrific nightmares. Her school performance had plummeted, and her teacher reported she was ‘withdrawn and not herself’. Her obsessive behaviour and fears had escalated, and her mother was concerned there might be a physical cause for her symptoms, perhaps a brain tumour. Examination was again normal, with no neurological signs or fever; her chest and throat were clear.

In view of the dramatic deterioration, the GP phoned the local child psychiatrist who, to his surprise, recommended an urgent paediatric referral.

Why was an urgent referral required? What could be the diagnosis?

Answer: After full specialist assessment, the patient was diagnosed with Paediatric Acute-onset Neuropsychiatric Syndrome (PANS), considered likely to have been triggered by a streptococcal throat infection.

Despite recognition by the NHS, NIMH and World Health Organisation there remains some controversy around PANS and the related Paediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS). As such, the PANS PANDAS Working Group, set up in 2022 with representatives from all major colleges, is embarking on collaborative work to develop standards of care and to define pathways and service models.

As GPs we are well used to recognizing that sudden behaviour change or delirium in older adults can be due to underlying infection, but less aware of PANS, its equivalent in younger people. Indeed, PANS was only described in 2012, building on the existing Streptococcal-specific PANDAS diagnosis. It is a broader term, and recognises that infections with agents other than Streptococci can cause the auto-immune reaction which gives rise to neuropsychiatric symptoms. Although Streptococcal infections remain the commonest trigger, others include Lyme disease, infectious mononucleosis, mycoplasma, influenza and Covid.

We are all well aware of the joint, renal and cardiac complications of childhood Streptococcal infections, but the neuropsychiatric effects are less well known, despite it being relatively common. The US PANDAS Network states that rates could be as high as 1 in 200, though there is great variability between sources. It is thought to account for up to 46% of childhood OCD.

The consensus statement for diagnosis of PANS gives the following summary criteria for diagnosis:

1. Abrupt onset. Abrupt onset of OCD rituals (handwashing, checking) or severe food refusal/restriction (though abrupt is not actually defined).

2. Concurrent symptoms. Must have at least two additional of: anxiety; emotional swings; aggression; regression; a decline in school performance; sensory issues such as an increase in sensitivity to light, noises, smells, tastes, or textures; motor issues such as tics; sleep problems.

3. Rule-out. Must exclude other potential diagnoses including Sydenham’s Chorea, Tourette’s, lupus and psychosis.

Often the condition will follow an infection, particularly Strep throat, 2-3 weeks on, though it may be precipitated by metabolic disturbances, other inflammatory reactions and psychosocial stress. By the time the patient is seen, there will be no sign of infection – though in PANDAS the ASOT will usually still be raised.

Prompt treatment reduces the risk of the symptoms persisting; in Abbi’s case the diagnosis was made on the basis of her acute onset OCD and tics, and her anxiety, school deterioration and sleep problems. The severity of her symptoms justified precautionary antibiotics and a single short course of oral steroids to reduce neuroinflammation.

Overall, the prognosis for PANS/PANDAS is good, though flare-ups are common (71% in one study) particularly if further infections occur. The same study showed persisting symptoms in only 12% compared with 40-60% in non-PANS childhood OCD. In cases where symptoms persist, the use of standard treatment options such as CBT are justified. Early recognition is essential in improving the prognosis.

In Abbi’s case her course was episodic and relapsing-remitting. Over the next year, she experienced three more ‘flares’ of symptoms, each time preceded by a mild cold or a confirmed Strep exposure in her classroom. Each flare was managed with a short course of ibuprofen for inflammation and antibiotics if strep was suspected clinically, and the flares became less severe and shorter in duration. Without such prompt initial action, her symptoms would have been much more difficult to control. In cases where infections have been addressed but psychiatric symptoms remain, talking therapies and similar CAHMS interventions still have a place.