Allergy symptoms can take many forms. They often manifest as itching eyes, swollen sinuses and sneezing. But they can also show up on your skin as hives.

Known medically as urticaria, hives appear as a red, itchy rash on the skin.

Hives can appear just about anywhere on the body and can be caused by ingesting food you’re allergic to or touching an allergen such as a plant, insect or fabric.

The most common foods that cause hives are nuts, eggs and shellfish. Insect stings, latex, bacterial and viral infections, pets, pollen and plants can also cause hives, as can medications such as antibiotics, aspirin and ibuprofen.

“All of these are based on your immune system’s appropriate and inappropriate response to outside influences,” says Dr. Alex Suda, a family medicine physician with Tidelands Health Pediatrics and Adult Medicine in Pawleys Island.

When it encounters an irritant, your immune system can go into overdrive, producing a chemical known as histamine in response to the trigger. In the case of hives, histamine can cause the tiny blood vessels in the skin to leak fluid, leading to the rash.

Hives can be a one-time event or a chronic problem, depending on the individual. People who know they are susceptible to getting hives should keep an over-the-counter antihistamine on hand for outbreaks, Dr. Suda says.

Whether hives are a one-and-done or an everyday occurrence, pay attention to what triggers them so you can avoid those triggers in the future.

“You’ve got to figure out how to avoid that exposure,” Dr. Suda says.

When you’re dealing with an outbreak of hives, avoid exposing the affected areas to hot water and wear loose-fitting clothing to avoid further irritation. Applying over-the-counter anti-itch treatments such as calamine lotion can relieve the symptoms.

Severe cases or chronic episodes of hives mean it’s probably time to see your provider to determine the cause and find long-term relief.