A tick bite can leave you allergic to steak

Ticks carry a sugar called alpha-gal in their saliva. Almost every mammal has it in its meat, but humans, great apes and Old World monkeys do not, so a bite can teach the immune system to treat it as foreign. Reactions to beef, lamb, pork or kangaroo usually start 4–6 hours after the meal, which is why the link is easy to miss. Gelatin in some capsules can trigger it too. Australian allergists were the first to describe it.