Omicron is infecting more kids than any prior variant. Here are the most common symptoms in children, according to experts.

• Omicron has been infecting many children as the variant surges worldwide.
• Data is scarce, but experts listed fatigue, headaches, and coughs as the most common symptoms.

As waves of the Omicron coronavirus variant surge around the world, children are falling sick more than they used to.

Although it is spreading widely, the variant is causing less severe illness overall, and children are especially unlikely to become seriously ill.

Insider spoke to experts and received some early data to help figure out what kind of symptoms kids tend to show from Omicron infections.

The most commonly noted were tiredness, sneezing, coughing, or a sore throat.

Duncan, a medical professor at King's College London, spoke to Insider about her work tracking symptoms of COVID-19 in children via the long-running ZOE COVID-19 study.

The study uses an app to allow participants to log their symptoms daily.

Based on preliminary results from a couple hundred cases of Omicron in kids aged 12-8, Duncan listed the following symptoms:

- Fatigue.

- Headache.

- Sore throat.

- Runny nose.

- Sneezing.

- Fever.

- Cough.

Other medical experts Insider spoke to noted less common instances of intestinal problems like diarrhea, and rashes.

In some cases, kids develop croup, when an airway infection makes a child sound like a seal or a dog barking when they cough.

Duncan noted that her data does not include asymptomatic cases of COVID-19. Most children in Duncan's set had been vaccinated, though she said patterns were "very similar" in unvaccinated children.

Vaccination seems to diminish the frequency and length of the symptoms, but it's too soon to know for sure, she said.

View from the frontline

Doctors working with children told Insider this report fits with what they have seen.

"Most children are getting upper respiratory/cold-like symptoms, regardless of age," Dr. John McGuire, chief of Seattle Children's pediatric critical care division, told Insider in an email.

Intestinal distress symptoms, fever, rashes, are also "good symptoms for parents to monitor for," he said.

Dr. Buddy Creech, director of the Vanderbilt Vaccine Research Program, said he has also been seeing mostly respiratory symptoms in this wave.

Dr. Lisa Saiman, Professor of Pediatrics at Columbia's Vagelos College of Physicians and Surgeons, said that croup appears to be an Omicron-specific symptom.

Saiman said that parents should not be overly worried, despite the concerning sound, as it typically "gets better on its own."

Another presentation said Saiman she was seeing in the hospital is bronchiolitis. "These children present with a cough and wheezing and sometimes need to be hospitalized if they are having any difficulty breathing," she said.

Both of these symptoms, however, can be caused by other respiratory illnesses. "Take home for parents is that it is very difficult to determine whether cold symptoms or croup-like symptoms are due to COVID or other seasonal respiratory viruses," Creech told Insider in an email.