Kourtney Kardashian had a bit of a scare over the weekend as she was advised to take her 11-month-old son Mason Disick to the hospital in an ambulance.

"Friday night Mason ate some peanut butter and had a little allergic reaction to it. He threw up within minutes of tasting it and got hives on his face," Kourtney explained on her blog. "I called 911 and the fire department came immediately. They suggested that we take him to the hospital, so we did."

Kourtney said that her son was in "good spirits" and "the whole time and didn't even know anything was wrong." The reality star mom added, "I learned such a lesson with this…to always follow my instincts and call 911. Always better safe than sorry."

Related stories on ETonline.com:Celeb GPS: Single Christina Aguilera Steps Out, Matt Barr Talks 'DWTS

Engine Shuts Down on Leonardo DiCaprio's Plane