• Question: I have an allergy to cats. Why do they make me sneeze?

    Asked by 738fasp29 to Stewart, Miriam, Laura, Kathryn, David on 13 Nov 2018.
    • Photo: David Ho

      David Ho answered on 13 Nov 2018:

      I’m no expert on this, but I think allergies are due to your immune system responding in an out-of-proportion kind of way. The immune system is your body’s defence against harmful viruses and bacteria, and things that cause disease. If a harmful microbe (a “pathogen”) gets into the body, most of the time the immune system kills it. Sneezing is a way of getting harmful microbes out of the body, and fast! But sometimes things can go wrong — when particles from cat fur get into your body, if you have a cat allergy your body thinks that they are trying to cause a disease, so it attacks them. This causes you to have some of the same reactions you have when you get a cold, like sneezing or streaming eyes.

    • Photo: Stewart Martin-Haugh

      Stewart Martin-Haugh answered on 13 Nov 2018:

      I actually don’t know! The great thing about science is not having to know everything. One of the best things you learn when studying science is how to read scientific papers and evaluate information critically. You can then apply that to anything else.

      You have to know some things about your main area, but it’s also good to know where you can look things up and get reliable information. I certainly don’t remember all the information I need every day.

      David gave what I suspect is the correct answer. Some people also sneeze when exposed to direct sunlight or other bright lights – no one knows why, but it does mean you can’t become a fighter pilot!