Spot the symptoms: Doctors decode the differences between RSV, flu and COVID

LOS ANGELES -- Flu, COVID and RSV are all viruses that may all seem like the common cold at first, but there are slight differences that can help parents get a sense of what is going on.

RSV symptoms peak at different times from the flu and COVID can be a mixed bag.

Pediatricians break down how the symptoms vary and what to look for. This winter's triple threat of flu, COVID and RSV is filling pediatric beds across the nation.

In Los Angeles County, hospital admissions for COVID have topped more than 1,000 and the youngest patients are being hospitalized for RSV.

"The youngest babies are at the most risk of bronchiolitis, which is a viral pneumonia type of thing, and also the elderly and the immunocompromised," said pediatrician Dr. John Rodarte with Huntington Health Physicians. "So the extremes are really the ones we worry about with RSV."

At Descanso Pediatrics in La Canada, doctors are going through boxes of rapid tests.

"We have a point of care test or rapid test for influenza A and B and also for RSV. In fact, our RSV test was out because we used up a lot of them," said Rodarte.

Due to the surge, more definitive lab tests are taking longer to process, but Rodarte said a test can help doctors guide their patients, but symptoms can tell you a lot.

"They'll be coughing, this just really dry, nonstop cough," he said. "For RSV, only worry if you have a young infant. It will look like a cold at first for the first three to four days. RSV peaks between day four to six so that's what you're watching for."

Flu feels bad right from the start.

"It tends to start out with a high fever and you're knocked down from the beginning," said Rodarte. "The headaches, the body aches, just feeling wiped out."

However, it gets tricky when it comes to COVID.

"COVID is really the big imitator, who knows what to expect with COVID?" said Rodarte. "It can look a little like a cold, it can look like a stomach virus, it can look like a sore throat. That's the one that can look like anything."

RSV, flu and COVID are all viruses that don't require antibiotics. The advice is to rest, drink plenty of fluids and keep a close eye on how symptoms are progressing.

"It's really more about supportive care through it," said Rodarte.

The biggest concern with all these viruses is secondary infections like pneumonia. Children with COVID are not usually treated with antivirals like Paxlovid, but someone with the flu might benefit from a drug like Tamiflu.

Talk to your doctor about your symptoms.