If you have moderate to severe allergy symptoms and you want to regain your usual comfort, you will require treatment to counteract the activity of mast cells and histamines. Histamines are responsible for immediate allergy reactions, such as itching, dripping from the nose or eyes, itching or redness of the nose or eyes, wheezing, sneezing, hives, or throat tightness. That is why antihistamines are the cornerstone of any allergy treatment. Ideally, you can target your treatment to the site of the symptoms. For example, you might treat a skin rash that involves a small area with corticosteroid creams applied to the skin, treat nasal symptoms with nasal sprays and use eye drops for eye symptoms. Targeting the site of the symptoms helps to limit side effects that may occur when allergy medications are taken by mouth.
It can be important to act quickly. The antibodies that attach themselves to allergens set off a chain reaction involving armies of cells and chemical signals. The immune system can in this way accelerate the initial reaction to an allergen, so if your allergy symptoms are severe, the sooner you start your treatment after an exposure the better.
Once your allergens have been identified, prepare an individualized treatment plan with a health care professional. This plan will focus on identifying your likely allergy triggers, coming up with strategies to reduce your exposure to triggers, knowing the best way to treat symptoms, and understanding what symptoms could make your allergies an emergency.
If your child has allergies or asthma, discuss treatment options with his or her health care professional. Many prescription and over-the-counter allergy medications can be used for children, although the dose will be adjusted for your child’s age and/or size, and oral medicines will need to be in a form that your child can easily swallow.
Antihistamines are medications that block the effects of histamines in allergy. Histamines are responsible for the itching in your skin, nose or eyes. They also cause an increase in nasal mucus or tear production, so histamines make your nose run.
Examples of antihistamines include chlorpheniramine (Chlor-Trimeton), diphenhydramine (Benadryl), clemastine (Tavist), fexofenadine (Allegra), loratadine (Claritin) and cetirizine (Zyrtec). Less-sedating antihistamines (Allegra, Claritin, Zyrtec) are available either by prescription or over the counter. The effects of chlorpheniramine last for about four to eight hours.
Side effects commonly include drowsiness and dry mouth. Especially in older adults, antihistamines can cause difficulty urinating, confusion, and an increased risk for falls or injury. If you have heart disease, check with a health care professional before taking any over-the-counter antihistamine preparations, since many of them are packaged in combination with decongestants, and decongestants can raise your blood pressure or heart rate.
Antihistamines are useful for treating hives. For people who have incomplete relief, some additional histamine blocking effect might be gained by combining an antihistamine medicine with a “H2 blocker” medicine (type 2 histamine blocker), which is usually used as an anti-acid treatment for treating heartburn. Examples of H2 blocker medication include ranitidine (Zantac) or cimetidine (Tagamet). Do not begin using cimetidine without asking your doctor about potential drug interactions with other medicines you may be taking.
Mast Cell Stabilizers
Cromolyn is a special type of medication that works on mast cells to prevent them from releasing histamine. This medication can be effective, but it works only if you take it before you are exposed to an allergen. It can be a useful treatment if you can take cromolyn on a regular schedule during your allergy-active season of the year or if you can anticipate an allergic reaction before you visit a home that has a trigger, such as animal dander. Cromolyn is available as an inhaler or nebulizer treatment (inhaled mist machine treatment) for asthma and as eye drops or a nasal spray (without a prescription) for hay fever.
Corticosteroids are potent allergy medications with important possible side effects. These medicines may be applied by spray (as a nasal inhaler, an asthma inhaler, or for some children, an inhaled medicine from a nebulizer machine), applied to the skin (as a cream, ointment, or lotion), taken by mouth (as a pill or liquid) or injected. Corticosteroids block multiple elements of the immune system that fuel the allergic reaction and are very effective for relieving itch.
Corticosteroid nose sprays do a better job treating allergic rhinitis (hay fever) than antihistamines. However, you will need to stick with the nose spray for at least a few days before the full benefit begins.
Corticosteroid inhalers are an extremely important treatment for asthma. They are able to dramatically reduce the frequency and severity of asthma attacks, if they are used as a regular asthma prevention medicine.
Because corticosteroids have such broad effects on the body, the potential for side effects is greater than with other medications. Happily, corticosteroids that are given by way of inhaler or nose spray rarely cause serious side effects. The potential for side effects is greater with oral corticosteroids than with corticosteroid sprays, inhalers, lotions, creams or ointments. Oral corticosteroids that are taken for an extended time weaken the immune system and may cause other problems such as high blood sugar levels, emotional reactions, bone thinning, or weight gain. Because of their potential side effects, corticosteroids by mouth or by injection are reserved for severe or dangerous allergy symptoms and are prescribed for the shortest period possible.
Revision date: June 11, 2011
Last revised: by Janet A. Staessen, MD, PhD