ELI5: Why does measles make you cough and not just give you a rash?

Imagine your body is like a big castle. Measles is like a tiny, annoying invader trying to take over the castle.

• First, the invaders (measles virus) sneak in, usually through your nose or mouth. Think of it like they're climbing over the castle walls!

• Now, your body has a special army called the immune system. This army's job is to fight off invaders.

• When the measles invaders get inside, they don't just stay in one place. They start copying themselves and spreading all over the castle! They especially like hanging out in your throat and lungs.

• Your immune system sees these measles invaders and starts attacking them. This fight is what makes you feel sick.

• Your body tries to get rid of the measles invaders by coughing. The cough is like the castle guards shouting, "Get out! Get out!" and trying to push the invaders out of the castle gates (your mouth).

• The rash is also part of the fight. It's like the battlefield outside the castle walls, showing where the immune system is battling the measles invaders in your skin.