What is an allergy? (Hint: It's related to our immune system)

When an allergy becomes life-threatening, a shot of adrenaline (epinephrine) is usually required to help save the person’s life. — Positive Parenting

After returning from a visit to a relative’s house, your baby starts coughing and wheezing.

You remember that she played with a cat at the house you visited earlier; could this be a possible allergic reaction?