Transcript for Girl develops aversion to eating, believes she's allergic to her saliva: Part 3
You think that's our plane? Probably. Reporter:alie barneand son parkerre heading to our nation's capitol. You want to wear the child's mask or the adma Reporter: They could have all kinds tupl Reporter:y are making a 1,200-mile pilgrimage, not for the si, but to see of country's mavens of the medical field. What's it like to be able to actually help the famit's been so despe for so LG? Well I don't think there's many gre rewards tn rely. Reporter: Meet Dr. Beth latimer, a firebrand pediatrogist withonths-long waiting list. She takes the pandas cases many otdot. I have felt tremendous amount responsibitfor these kids.ee people move from, like oneide of th country to the the parent get divorce because ey't deal with the trauma of this illness. There you go. Good J. Reporter: Latimer started seeing pandas patients 15 years ago and qukly became a las resortor parents who believe a simple strep throaole their children. Parents like Natalie and her husband Brian, who took parker to more th a dozen doctors theihome state of Minnesota looking for a panacea for pandas alth limitedesults. I would have to say most of the time I would bring it into these oct appointments an they would go hmmm. That's interesting. Thateird. Ny ever said , I can'lioing that, tsatut. Thank you for flying with us. We should be on the ground shortly. Reporter: That is, until they went to E Dr. Latimer C. Mom and parker win the ding. She goes by Beth. Hi there. Doctor latimer this is parker. Hi parker okay, so tst thing iant you to do isk right aty no, okay? Reporter: L spends oveo hours evaluating parker medically. Now turn your head over wards the window. Reporter: Learning his and you can see it almost looks like. Pct And then instead of cursi he started printing, and then his printing started to look more like,be kinderrten. Reporr: Buterhaps the mostpelling, visual evidence Dr. Latimer gets to see is . The dramic, at Tim disturbing, home video the Barnes's took to document R sos . Come on. You can it, thzure? That's so scary. His eyes twitching. Whate I recording? Because I couldn't believe it was happening, becau wouldn't believed myself if I told myself. This is so biza it's like a short circuit in his N. Reporte behavior ranging fromunrespsive. That was him he's just catatonic. He's lt where else Reporter: To full-on rage. Holdttogether park. He is starting to wig and he knows it. Reporter: Moaning, whing-et away. Stop talking and you're all going to kill me eventually, I know it. Parker. Reporter: He eventually stoppelking altother. His was T he spent four hours pushingselfn the R. Ha so disturng. It's like this. He would just freeze up. Not all the but that'a good example. Would he respond if you talked to him? Nop he would not respond. Okay. A he woulve those almost every day It'okay, parker. I got you. So, does he have pandas? S he have ndas? He has paas. He has pandas. Eporter: Datimer say she knows pandas when she sees . You people. Rte comes a relief to some parents who say their ctors onlyolem their dscrazy. Every day for me was trying nor. What madeou want to cry? You S child, yoknow, robbed of eir life. There is nothing quite like it. Reporter: Tim sorel isn't a or, he's ailmmaker, who pped into a robust and vibrant network of pandas parents for his dontd craz He would literally scream bloody murder like a terror cry, not justi'm not getting my wa terror in S face. Reporter: Seven sets of rents funned their harrowing home videos to hoping he could connect the dots between what started as rep and end like this. I would get terrible phon calls the middle of the night. They're desperate. They're truly desperate. What do Ty ask you in the middle of the night? What do you think I shodo ne? Where can itu? What have you heard? He was comply dysfunctional. He would uri on himsel he was completely overwhelmed with rituals. Reporter: One of the most unusand curioucases in rel's film Katherine Ulicki. This is not my daughter. The way she was like a couple ek as a 9-year-old sudden started exhibiting bizarre behavior of her own. Reporter: Not screami fits or cosiather an aversion T eating. I promise you guys if I H to eat ts there would be an allergic reaction. To an apple. , Really iromise you. Promi I would he allergicaction. Orter: One day, S stopped eating altogether. What did you think of this? I had no idea what was going on. You can do it. You can do it. I waso close. Reporr: Kathryn, who hardly resembles her younger self today, mystifiedoo. You weren't Loh, my god have to se weight? No, I like so far from that fact I would get so sca like I thought my parents were poisoning me. Reporter:athryn had had a long standing allergy to sesame,but this lelf paranoia was brand new. Because you wa to eat? Yea Reporter: You wanted to drink? Yeah. Reporter: And yet you just couldn't? Yea like scared tallow my own saliva. So would just the whole entire day. Reporter: What were you afraid of by swallowing? Like uld have aalrgic reaction. Orter: To ur own spit? Mm-hmm. Reporter:he up in a hospit, being fed through a tube in her nose. Look what they did to me today. This. Reporter:ut things on worse. You don't go from zero to crazin that short a period of time from a perfectly Normal ay I was like crying my dad and I was like I want to die. That's just heartbreg. Th idea a 9-year-old girl wanting to end it all. Its HD to put io words you're just second by second, minute by minute. Whileou're frozen in fear. Reporter: What was the thing afraid of? Kid's gointo Repter: Cominup -- Hi, Catherine how are you, Dr. Latime Hi. Repter: Both Katherine and parker think they've found their lifelines.but some tnk Dr. Beth latime is out on mb. We are going overboard on the treatment could this all be junk science? You'keptical tt pandas ex. Es. Reporter: Deeply skeptical. Yes. Rorter: Andthers that castlame on thpa all because his parents shopped around for a doctor. Willing lame Kevin neurologics on strepnstead ofitting thelikely pd itn to him getically. That right E, that waan attack on me and all the other families that haveght to actually help their children.
This transcript has been automatically generated and may not be 100% accurate.