Eight-year-old Mikey Emhof has only been on one sleepover and he barely ever plays at a friend’s house. Why? He’s allergic to pretty much everything, says his mom, Cathy, of Fairfax, Virginia. Pet dander, dust mites, feathers, pollen, dairy—you name it, poor Mikey’s probably allergic to it. And his allergies are life-threatening. From hives to asthma to anaphylactic shock (where numerous areas of the body are severely affected, which can lead to difficulty breathing and swelling of the airway), there’s no telling how his body will react to an allergen. “He’s been up the street to play with friends and he’s had to come home because they had a dog and it licked him and he broke out in hives,” Cathy said. Once, his whole hand swelled just from touching a patch of spilled milk.

Even though Mikey is careful and knows how to deal with his allergies and asthma, his parents are still nervous about what could happen to him when they’re not around. “He doesn’t just go to someone’s house without us checking out the situation and discussing it with the parents,” explains his mom. “[And] he cannot eat something if we do not know every ingredient and how it was processed.”

Do allergies affect your life or that of your child or other family members? Here’s what you need to know to help prevent and treat allergy symptoms.