“I took him to the doctor this morning, and he tested POSITIVE for INFLUENZA B. He has had NO symptoms. No fever, no cough, and no runny nose,” Willard wrote in the post. “He only has hives. Please keep watch on your children so if they develop hives, please call your pediatrician. I have never heard of this symptom,but it is obviously something to be on the lookout for.”
The post with Willard's claim has been shared over 227,000 times. Willard did not say whether or not her son got a flu shot this season. In some people, the flu shot can cause hives if they are allergic to eggs, because the vaccine is made using egg-based technology. According to the American Academy of Dermatology, infections could be a cause of hives.