EGG HARBOR TOWNSHIP — Eight-year-old Avery Eykyn is a fun-loving, energetic and active young girl who loves sports and rarely complains when she’s not feeling well.

So when Janelle Eykyn noticed her daughter wasn’t shaking off a headache Jan. 29, she became concerned.

“Something just felt wrong,” Eykyn said.

From there, Avery’s symptoms spiraled.

Her fever spiked, reaching 104. She became lethargic and developed rosy cheeks and cracked lips, and began vomiting.

Two days later, Eykyn packed up her daughter, leaving her 11-year-old son, Ryan, home with dad, Mark, a teacher in Pleasantville, and trekked up to Children’s Hospital of Philadelphia, where tests would eventually show Avery had MIS-C.

Avery was the first documented case in Atlantic County of the rare, new illness affecting children.

MIS-C stands for multisystem inflammatory syndrome in children, and the illness came about as a result of COVID-19. Those diagnosed have been 20 years old and younger.

There are 105 cumulative cases of MIS-C reported in New Jersey, up from 95 as of Monday. The Centers for Disease Control and Prevention reports 2,060 cases and 30 deaths nationwide as of Feb. 1.

Avery’s case of MIS-C is not yet reflected in New Jersey’s case count. New Jersey health officials said that is likely because she was hospitalized in Pennsylvania and it hasn’t been reported here yet.

“It’s not common, but it is severe, and enough children have COVID that we see a fair number of kids with it,” said Dr. Lawrence C. Kleinman, pediatrician, professor and vice chair for academic development at Rutgers Robert Wood Johnson Medical School.

Kleinman, who has been studying MIS-C and has contributed to medical journals on the topic, said the disease affects two or more organ systems and typically occurs between three and four weeks after exposure to COVID-19.

Abdominal inflammation is most common, he said, followed by cardiovascular inflammation, but researchers believe some children who have MIS-C may only have one system of inflammation. Patients usually have a fever and gastrointestinal distress, and will be fatigued. Rash, trouble breathing and discolored skin and lips are other signs.

“Some of the kids get very, very sick. With appropriate care, almost all of them recover, but that is not 100%,” Kleinman said.

Avery spent a week in the hospital at CHOP hooked up to IVs and undergoing various tests. Her symptoms would come and go. On Feb. 6, she was finally able to go home.

Avery did recover, for the most part, but is still not permitted to resume her regular activities because of concerns about her heart and other organs. She is still receiving bloodwork and follow-up tests. The third-grade student at Swift Elementary is participating in school virtually for now, and hopes to get back to the soccer fields soon.

On Thursday, Avery said she was feeling good.

“I can’t play any games,” she lamented.

Janelle Eykyn said she wanted to share her story to help other parents. In Avery’s case, she never tested positive for COVID-19, but during her stay at CHOP did test positive for COVID-19 antibodies, which means she was an asymptomatic carrier of the disease at one point in early January or late December.

None of the other Eykyns tested positive for COVID-19 or antibodies.

Janelle Eykyn said she had never heard of MIS-C until she looked it up online after speaking with her pediatrician. Reading about the symptoms is what made Janelle rush Avery to the hospital.

“When I went to urgent care here, everyone was so fixated on COVID, I just knew deep down this is not COVID,” Janelle said.

She said more parents should research this illness even if they don’t think they had a COVID-19 exposure, as in Avery’s case.

“Had I waited another day, she could have been with a tube down her throat. Better safe than sorry,” Janelle said. “Get there as early as possible and ask for bloodwork. Hopefully it’s nothing, but it could be something.”

Kleinman said that while COVID-19 cases and mortality rates among children aren’t as high as for more vulnerable populations, such as the elderly or those with heart conditions, the real impact on children has yet to be determined.

“This pandemic began with a myth that children were spared COVID, and even though it’s been shown to not be true and to be just wrong, it’s shaped all the information we have,” he said. “It’s a really complicated issue.”

The doctor said that while there are a small number of healthy kids who have severe cases of COVID-19, of the children diagnosed with MIS-C, 73% were previously healthy.

“COVID is potentially devastating for children, and therefore you can’t be cavalier,” Kleinman said.