Definition

     Allergic reactions can occur in response to many foods, cosmetics, drugs, and environmental triggers. Reactions can occur within a few minutes or often after a second exposure.
 

Causes

Symptoms

Types of allergies

     While there are many types of allergies, some of the more common ones include:

• Food allergies, which are more common in children than adults. Food allergies are most common in people who have an inherited tendency to develop allergic conditions. These people are more likely to have asthma and other allergies. For more information, see the topic Food Allergies.

• Medicine allergies. Many prescription and nonprescription medicines can cause an allergic reaction. Allergic reactions are common and unpredictable. The seriousness of the allergic reaction caused by a certain medicine will vary.

• Allergies to insect venom. When you are stung by an insect, poisons and other toxins in the insect's venom enter your skin. It is normal to have some swelling, redness, pain, and itching at the site of a sting. An allergic reaction to the sting occurs when your body's immune system overreacts to the venom of stinging insects. For more information, see the topic Allergies to Insect Stings.

• Allergies to animals, which are more likely to cause breathing problems than skin problems. You may be allergic to your pet's dead skin (dander), urine, dried saliva, or hair.

• Allergies to natural rubber (latex). Some people develop allergic reactions after repeated contact with latex, especially latex gloves. For more information, see the topic Allergy to Natural Rubber (Latex).

• Allergies that develop from exposure to a particular inhaled substance in the workplace. These are called occupational asthma.

• Allergies to cosmetics, such as artificial nails, hair extensions, and henna tattoos.

Screening and Diagnosis

• Onset of reaction often related to use of new product.

• Previous history of similar reaction.

• Rashes on a single area or over the entire body.

Treatment

• Most cases resolve when the cause is removed.

• Over-the-counter antihistamines will help with the itching and swelling.

• Physicians in severe cases can give adrenaline.  Severe reactions should be treated in the emergency room.

• Steroid creams or oral medications may also help treat the symptoms.

Prevention

• Avoid triggers such as foods and medications that have caused an allergic reaction, even a mild one, in the past. This includes detailed questioning about ingredients when eating away from home. Ingredient labels should also be carefully examined.

• If you have a child who is allergic to certain foods, introduce one new food at a time so you can recognize an allergic reaction.

• A medical ID tag should be worn by people who know that they have serious allergic reactions.

• If you have a history of a serious allergic reactions, carry emergency medications (such as diphenihydramine and injectable epinephrine or a bee sting kit) according to your health care provider’s instructions.

• Do not use your injectable epinephrine on anyone else. They may have a condition (such as a heart problem) that could be affected by this drug.