Allergic Reaction Diagnosis and Self-Care at Home

Allergic Reaction Diagnosis

For typical allergic reactions, your health-care provider will examine you and ask questions about your symptoms and their timing. Blood tests and X-rays are not needed except under unusual circumstances.

In case of severe reactions, you will be evaluated quickly in the emergency department in order to make a diagnosis. The first step for the health-care provider is to judge the severity of the allergic reaction.

• Blood pressure and pulse are checked.
• An examination determines whether you need help breathing.
• Often, an IV line is placed in case you need anti-allergy (antihistamine) medications quickly.
• If you can speak, you will be asked about allergy triggers and previous reactions.

Self-Care at Home

Avoid triggers! If you know you have an allergic reaction to peanuts, for example, do not eat them and go out of your way to avoid foods prepared with or around peanuts (see Food Allergy).

Self-care at home is not enough in severe reactions. A severe reaction is a medical emergency.

• Do not attempt to treat or "wait out" severe reactions at home. Go immediately to a hospital emergency department.
• If no one is available to drive you right away, call an ambulance for emergency medical transport.
• Use your epinephrine auto-injector (Epi-Pen, Auvi-Q) if you have been prescribed one by your doctor due to previous allergic reactions (see "prevention" below).

Slight reactions with mild symptoms usually respond to nonprescription allergy medications.

• Oral antihistamines
• Loratadine (Claritin or Alavert), cetirizine (Zyrtec), and fexofenadine (Allegra) are nonsedating antihistamines that can be taken over the long term.
• Diphenhydramine (Benadryl) can also be taken but may make you too drowsy to drive or operate machinery safely. It can affect concentration and interfere with children's learning in school. These medications should be taken for only a few days.
• For rashes or skin irritations, an anti-inflammatory steroid cream such ashydrocortisone can be used.

For small, localized skin reactions, use a cold, wet cloth or ice for relief. Apply a bag of frozen vegetables wrapped in a towel as an ice pack.