You can prevent hives by identifying and avoiding the particular circumstance or substance that triggered your skin reaction. If your doctor determines that you are allergic to insect venom, you may be advised to keep an epinephrine kit for emergency injections to prevent anaphylaxis. Keep the medicine in a convenient place if you work outside or play a sport. Keep an antihistamine in your medicine cabinet and take it the first signs of hives or itching. Older adults and people with heart disease should double check with their doctor before buying or taking antihistamines.