It started with Connor Entrop's hair.
One day last winter, when he was 10-and-a-half, Connor's mother, Corie, discovered him yanking fistfuls of his own hair from his head in their home in Alberta, Canada. He started in on their dog's fur, too.
Connor's behavior became increasingly erratic, he began suffering panic attacks and devolved into psychosis and even became suicidal. Corie was terrified, and perplexed by what was happening to her son, she told CTV.
It took months for a doctor to ask if he'd been sick recently. Connor had been extremely ill with what his mother thought was strep throat (though doctors didn't test him).
His immune system's response to the virus had instead attacked the 10-year-old's own body and caused severe brain inflammation, a rare reaction termed Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus (PANDAS).
But nearly 30 years after the response was named, it remains controversial - and some experts say that the strep infection is just a coincidence in some children with obsessive compulsive disorder or other mental health issues.
For most of the school year, Connor was in and out of class, where he was sometimes violent.
The hair-pulling became compulsive, and Connor couldn't explain why he was doing it.
'I just need to pull out my hair,' he told Corie, according to CTV.
His behavior looked at first like classic obsessive compulsive disorder, which affects about half a million children in the US.
So Corie shaved her son's head and tried to manage his increasing hyperactivity.
That winter he became very sick and had to go to the emergency room.
But once Connor recovered from that illness, he seemed to dive deeper into a mental one.
One day at school, a teacher refused to answer the questions the was peppering her with. Connor's response was to plunge a pencil into his own arm.
At home, the elementary school student talked almost incessantly of suicide and Corie caught him trying to hurting himself, multiple times.
'He would try to jump out of moving vehicles when I was driving,' she told CTV.
'He was threatening suicide a lot. He would barricade himself into his room and string stuff around his neck trying to choke himself out.
Connor had been diagnosed with ADHD, and, when his outbursts began, his psychiatrist suggested it was related anxiety and put him on an anti psychotic drug.
But nothing was helping. For months, Connor seemed to just spiral.
At a loss, Corie finally enrolled her son in a rehab program designed for children whose health issues were making school difficult or impossible to attend.
By August, a specialist finally had a name for what was happening to Connor: PANDAS.
The condition was first described by Dr Susan Swedo in 1980, who is now the chief of the National Institute of Mental Health's Section on Behavioral Pediatrics.
Connor's sudden and scary changes seemed like a perfect fit for Dr Swedo's criteria: sudden onset of OCD or tightly restricted eating and at least two of a number of behaviors, including irritability, ADHD-like behavior, depression and anxiety.
PANDAS is rarely diagnosed and not well studied or understood.
But Dr Swedo theorizes that children younger than 12 - the group most likely to be affected by PANDAS - often don't have strep antibodies.
So when they get their first strep infection, these naive antibodies have to try to hunt down the virus, which is particularly adept at camouflaging itself from the immune system.
This means the antibodies sometimes attack healthy tissues in the body.
If they mistakenly target the basal ganglia, neurons deep in the brain that play a role in everything from motor functions to learning, cognition and emotion, Dr Swedo believes a child may suddenly develop neurological and psychiatric symptoms.
But strep is extremely common, and there are so many other possible indicators of PANDAS that it is likely under-diagnosed.
For these same reasons, many experts are skeptical that the relationship between the infection and the sudden behavioral changes is real at all.
And in turn Dr Swedo says that controversy is why there are so few cases.
Nonetheless, many doctors across the country do treat PANDAS, prescribing prophylactic antibiotics.
This treatment course is based on an older and much better documented movement disorder, sometimes accompanied by OCD behaviors. that some children developed after having overcome rheumatic fever.
Connor started taking antibiotics three times a day every day in June.
'It's like I have my old kid back,' Corrie told CTV.
'He’s still Connor. He still has ADHD. He can still be a pain in the butt, but he’s healthy again.'
Treating PANDAS now may someday leave Connor with another medical problem, however.
Pediatricians and public health officials alike are increasingly concerned over antibiotic resistance.
The fear is that germs that Connor's body comes into contact with on a day to day basis will 'learn' from the antibiotics he's on and mutate so that they can beat the drugs.
This renders antibiotics useless, and the more people take the drugs long term, the more of bacteria learn to outsmart them. It is one of the greatest public health concerns of our time.
But, Connor, now 12, has at least regained his day-to-day life - and his hair - after a terrifying year and a half.