- Allergic Rhinitis
- Allergic Skin Conditions
- Food, Medication And Insect Venom Allergies
Anaphylaxis is an immediate allergy reaction, and it can put you in immediate danger. When symptoms are life threatening, such as low blood pressure, difficulty breathing or unconsciousness, emergency measures must be taken. This includes using medications such as epinephrine to raise blood pressure, a medicine that must be injected or given through an intravenous (IV) line. Rarely, a person with anaphylaxis must have a breathing tube inserted to make sure the airway does not close, and may require the assistance of a mechanical ventilator (breathing machine.) Frequently, doctors need to give IV fluids to raise the blood pressure.
Treatment for full-blown anaphylaxis includes antihistamines and corticosteroids to calm down the immune system response. Sometimes, an H2 blocker (a stomach acid reducer that also blocks allergy receptors) is also prescribed, because the combination of an antihistamine medicine and an H2 blocker medicine may offer you the strongest protection against histamines, the allergy substances responsible for anaphylaxis symptoms. Asthma medicines (inhalers or nebulizer “mist” breathing treatments) can be given if necessary. Fortunately, when treated early enough, symptoms can be reversed quickly, within a day. Medications other than epinephrine are typically continued for three days or longer to make sure the immune system response is adequately treated.
Most people use antihistamines to treat symptoms of allergic rhinitis, such as runny nose, sneezing, itchiness and irritation of the eyes and nose. Antihistamines are best started before peak allergy season or at the earliest signs of symptoms. Drowsiness is a common side effect. Less-sedating antihistamines are available, but they are more expensive and are not provided by some insurers if a person has not already tried and experienced side effects from less expensive medicines. Antihistamines should be avoided by a person who has a medical problem that limits the emptying of the bladder (such as an enlarged prostate), because these medicines can make it more difficult to empty the bladder. Antihistamines can put an older individual at risk for stumbling and falling, or can cause confusion in an older person.
Nasal corticosteroid sprays are effective alternatives to antihistamines. Examples include budesonide (Rhinocort) and beclomethasone (Vancenase, Beconase). When they are used regularly and have been given enough time to have their full effect, nasal corticosteroid sprays control symptoms in the nose better than antihistamines do. If the sprays irritate the nasal passages, you may find it helpful to use a nasal saline spray afterwards, or to use a variety of nasal spray that is packaged in a water based (aqueous, or AQ) spray.
Some people rely on a cromolyn nose spray (Nasalcrom), which does not require a prescription and cause the least amount of irritation and other side effects. Cromolyn sprays work only when taken before exposure to an allergen, so they must be used before very predictable allergy exposures or used on a regular schedule (several times a day).
Azelastine (Astelin) is an antihistamine nasal spray available by prescription. It may be a good choice if you have significant side effects from oral antihistamines.
When head congestion is the primary symptom of allergic rhinitis, decongestants may provide more immediate relief than other treatments. Decongestants are effective when you have difficulty breathing through your nose and when your sinuses feel blocked and full of pressure. They are available as pills, liquid (pseudoephedrine, or Sudafed) and nasal spray (oxymetazoline, or Afrin). (Nasal sprays are intended for short-term relief or “jump starting” your fight against allergy symptoms. They can cause a paradoxical increase in your symptoms if used for more than three days without a break.)
Decongestants affect the end result of the allergic reaction rather than the root (the immune system). By constricting the blood vessels, decongestants reduce the swelling and inflammation that cause a stuffy nose and watery eyes. This allows the passage of air and mucus. Side effects from oral decongestants can include insomnia, high blood pressure, and a racing heart rate. Consult your health-care provider before using these medications if you have high blood pressure, a history of Stroke , or Heart disease.
The treatment of asthma generally focuses on opening airways and controlling inflammation. Symptoms during a flare require fast-acting airway openers such as albuterol (Proventil, Ventolin). In flare-ups that cause persisting symptoms, corticosteroids are given intravenously or by mouth to calm inflammation over several days or weeks of treatment. If you have frequent asthma symptoms, then it is critically important for you to use regularly scheduled medicine that can control inflammation and prevent symptoms. Usually this prevention medicine takes the form of a corticosteroid inhaler (inhaled steroid). There are many different brands.
Avoidance of triggers is an important part of asthma treatment. Because asthma and allergies tend to go hand in hand, identifying your allergy triggers can help you to take sensible steps to avoid them. Avoiding your triggers may mean staying out of households where there are pets, or it may mean that you cover your mattresses with a zipped allergy control cover and regularly launder your bedding, to reduce dust mite exposure.
Allergy shots are used to treat fewer than one out of ten people with asthma. They can be considered if your triggers are known, but allergy shots don’t usually eliminate asthma and they are considered risky for people with asthma that is severe. Reducing exposure to allergens and treating your allergies aggressively with medications can dramatically improve your asthma symptoms.
Long-term treatment of asthma requires an asthma management plan, which can be created for you by your doctor. Your plan is your guide about how to adjust medicines whenever symptoms become active, so you can keep ahead of your asthma.
Allergic Skin Conditions
Treating any allergic skin condition may requires either antihistamines, corticosteroids (topically or by mouth), or a combination of these medicines. Itchiness is the hallmark of an allergic rash. Scratching can make the rash worse because scratching stimulates more inflammation and more histamine release. Itching can often be reduced by using an antihistamine. Any brand of antihistamine can be helpful. Diphenhydramine (Benadryl) is a frequently chosen over-the-counter antihistamine that can reduce itching, but can make people drowsy. It is a reasonable choice if your itching keeps you awake, and you plan to use it at bedtime. Chlorpheniramine (Chlor-Trimeton) is an inexpensive antihistamine that does not cause as much drowsiness as Benadryl, and over-the-counter loratadine (Claritin) causes less sedation than either of these medicines. The prescription medication Atarax (hydroxyzine) is another antihistamine that is often chosen to reduce itching. Antihistamines can reduce the redness and swelling of some types of allergic rashes, including hives. They don’t noticeably improve the appearance of rashes from allergic eczema or contact dermatitis, but they may help to limit itching from these problems.
Corticosteroids by mouth are usually able to control itching and are used to treat some allergy rashes that are either widespread or stubborn in their response to other treatments. These medications are used only in selected cases because they have side effects, including mood changes, high blood sugar levels and high blood pressure among others. They also increase your risk of infection and reduce your bone strength, particularly if they are used for a long time.
Low-strength topical corticosteroids (such as hydrocortisone, or Cortaid) also are available over the counter. In general, you should consult your doctor before you consider using any form of corticosteroid to treat a rash. These medicines have side effects (including skin thinning and skin discoloration) and you should only use them with a doctor’s recommendation, unless you are treating a problem that is well known to you and for which they have been recommended in the past.
Topical corticosteroids can be very effective for contact dermatitis (a reaction to poison ivy or poison oak, rashes resulting from exposure to metals) if the rash is diagnosed early and affects a small area. Topical corticosteroids are also frequently used to treat eczema. Steroids come in lotion, cream or ointment form. Ointments lock in the most moisture and can penetrate thickened, scaly skin. A prescription is needed for steroids of medium or high strength; examples include triamcinolone (Kenalog), fluocinonide (Lidex), fluocinolone (Synalar) and hydrocortisone valerate (Westcort). Topical corticosteroids should not be used on the face, groin or genitals. Follow your health-care provider’s directions on the duration of use (usually no more than two or three weeks at a time).
Severe cases of contact dermatitis can be very itchy and may blister and weep. If you develop weepy areas, you should always meet with your doctor to have the rash examined. Surface moisture may make it impractical for your rash to be treated with topical steroids, unless the moisture is reduced with an astringent (drying) solution (such as Domeboro). Surface moisture may also concern your health care professional about the possibility of infection.
Your health care professional or your pharmacist may recommend gauze dressings. Oatmeal baths (Aveeno) can also help soothe the skin. Calamine lotions may reduce itching in mild reactions.
Allergic eczema (atopic dermatitis) or contact dermatitis affecting the face or a large area of the body is usually treated with oral corticosteroids. The duration of treatment may be anywhere from one week to one month depending on your response to treatment and the severity of the rash.
For the treatment of atopic dermatitis or eczema, topical pimecrolimus cream (Elidel) or tacrolimus cream (Protopic) are also effective, but these medicines increase the risk for cancer. These medications may be used in children over the age of two.
The initial treatment approach for any of these allergies is the same because they may lead to severe, life-threatening symptoms or anaphylaxis. The first step is recognize symptoms of anaphylaxis. If you have any of these symptoms, avoid further exposure to a suspected allergy trigger even if your symptoms are mild (for example, stop eating, or stop taking doses of a newly prescribed medication). Call your health-care professional for advice if you are having mild symptoms, and get help from a bystander or by calling 911 so you can be evaluated in an emergency room if your symptoms are worsening or are severe. If you have been stung by an insect, remove the stinger from your skin by scraping it away gently with your fingernail.
If you are having symptoms that seem similar to a previous allergic reaction to a food, medication or insect sting, take an antihistamine immediately. If you develop potentially life-threatening symptoms, such as difficulty breathing, dizziness or chest pain, call your local emergency number and use an EpiPen if you have one. Medications for severe allergic reactions can include combinations of epinephrine, an antihistamine, an H2 blocker (a stomach acid reducer that also blocks allergy receptors), asthma inhaler treatments, and corticosteroids by mouth.
Revision date: June 21, 2011
Last revised: by Dave R. Roger, M.D.