Allergies occur as a result of an overreaction of the immune system. Normally, the immune system protects the body from invaders such as viruses and bacteria that can cause illness. People with allergies have an immune system that reacts to a harmless substance as though it was harmful.
A material that causes the immune system to overreact is called an allergen. Common allergens include:
- pet dander
- foods, such as eggs and nuts
- bee stings
The body will develop antibodies to a material after exposure. When a person is later exposed to the same allergen, an allergic reaction occurs.
- Allergy medications can be vital for stopping a dangerous allergic reaction.
- Antihistamines, decongestants, epinephrine, and nasal steroids can all help stop allergy symptoms.
- Allergy symptoms are different for different allergy-causing materials but can affect the respiratory and digestive systems and skin.
- The best way to prevent a reaction is to avoid allergens.
There are many treatments for allergy relief. Here are some common classes of medication:
Antihistamines are one of many options available to treat or manage allergies.
Antihistamines are effective medications used mainly for hay fever and other allergies. These medications counter the effects of histamines, a substance made by the body to help the immune system fight invading substances.
Histamines produce unpleasant symptoms during an allergic reaction, such as sneezing, a runny nose, and itchy eyes.
Antihistamines are available over the counter (OTC) and by prescription. These medications can be in the form of tablets, liquid, nasal sprays, creams, and eye drops.
Older antihistamines, such as Benadryl and Chlor-Trimeton, relieve allergy symptoms but can cause drowsiness. People should avoid driving while using these medications.
Other common side effects of these older antihistamines include:
Newer antihistamines have fewer side effects and are less likely to cause drowsiness, except Zyrtec. These medications come in tablet form. Brands include Allegra, Alavert, Clarinex, Claritin, Zyrtec, and Xyzal.
Common side effects of these antihistamines include:
- a headache
- a dry nose
- dry mouth
- nausea and malaise
Decongestants can help clear a stuffy nose and sinus congestion. The medications shrink blood vessels in the nose and open up nasal passages.
These medications are often available OTC in pill or spray form. Examples of decongestants include Afrin Nasal Spray, Sudafed PE, and, behind the pharmacy counter, Sudafed.
Pregnant women and people with high blood pressure are advised not to take decongestants and should speak to their doctor.
Side effects of taking decongestants by mouth may include:
- a headache
- dry mouth
- trouble sleeping
Side effects of decongestant nasal sprays include:
- a dry or runny nose
- a temporary burning or stinging sensation in the nose
Nasal corticosteroids are prescription medications that relieve symptoms by reducing the inflammation caused when an allergen is present. Corticosteroid nasal sprays, such as Flonase and Nasacort, can help relieve nasal stuffiness, sneezing, and a runny nose.
Side effects of nasal corticosteroids include:
- unpleasant smell in the nose
- foul taste in the mouth
- nasal irritation
Auto-injectable epinephrine is used to treat a life-threatening allergic reaction called anaphylaxis. This prescription medication is used to reverse potentially fatal symptoms, such as difficulty breathing, throat swelling, a weak pulse, and hives.
Some brands of these medications include EpiPen or Auvi Q.
Epinephrine is delivered by self-injection. Its effects are rapid but do not last long. As a result, a person should seek medical attention to treat anaphylaxis.
Allergy injections, or immunotherapy
Some people with allergies have benefited from allergy shots or immunotherapy that reduce the allergic reaction.
An allergist injects a small amount of the allergen so the body can develop immunity. The process can be effective in ending an allergy or stopping the progression of a minor allergy into a more serious one.
Immunotherapy treatment takes roughly a year to be effective and is then maintained for another few years. The side effects of treatment are redness and swelling at the injection site. Some people may experience allergy symptoms, such as a stuffy nose.
Nasal irrigation with a neti pot can help flush allergens from the nose.
There are some alternatives for relieving allergy symptoms. They can be used alone or in combination with the above medications.
Nasal irrigation washes allergens and mucus out of the nose, which can make breathing easier. Saline is poured or gently pushed into the nostrils using a bulb syringe or neti pot. People should use procedures the U.S. Food and Drug Administration recommend to avoid getting a sinus infection.
Saline nose spray flushes allergens like pollen and dust out of the nose. These sprays are less irritating than nose spray with medications.
Healthy eating has many benefits, including reducing inflammation caused by allergens. Food allergies require avoiding certain foods, but a balanced, nutritious diet can still be achieved.
Popular anti-inflammatory foods include:
Cold compresses can also help with swollen eyes and painful sinuses.
The overreaction of the immune system to an allergen leads to inflammation, and this inflammation is what causes allergy symptoms. Allergy symptoms vary by the type of allergen and how severe the allergic reaction.
People with a skin allergy may have symptoms of redness or a rash after contact with an allergen, such as latex or an ingredient in laundry detergent.
Seasonal allergies or hay fever are very common. Around 10 to 30 percent of people worldwide are affected, and the prevalence of allergies may be increasing.
People with seasonal allergies have symptoms resembling the common cold, including:
- an itchy and runny nose
- swollen eyes
- itchy throat
People with allergic reactions to foods have different symptoms, some of which can be severe:
- swelling of lips, mouth, or face
- stomach cramps
- hives, a red and itchy rash
- shortness of breath
Some people with severe allergies to foods, bee stings, or medications may experience anaphylaxis or anaphylactic shock.
Some of these symptoms include:
- stomach cramps
- narrowing of the airways
- a swollen tongue or throat
- wheezing and trouble breathing
- rash or itching
- a weak and rapid pulse
- nausea, vomiting, or diarrhea
- dizziness or fainting
Anaphylaxis can be fatal, so it is vital to seek medical attention
When to see a doctor
Allergies are often a minor inconvenience, but some can pose a serious threat to health, such as allergic asthma or anaphylaxis. An allergy specialist can evaluate and prescribe an appropriate treatment.
The American College of Allergy, Asthma, and Immunology (AAAAI) recommend that people visit an allergist in the following cases:
- You regularly find it difficult to catch your breath
- You experience hay fever for most of the year.
- OTC medications do not reduce allergy symptoms or cause severe side effects.
- Allergy symptoms interfere with daily life.
Be sure to check food packaging to make sure it does not contain potential allergens.
The way to avoid allergic reactions is to keep away from allergens, if possible.
People with food allergies need to be careful about how food has been packaged and prepared. Cross-contamination can occur where a small amount of an allergen ends up in a dish. A restaurant serving a peanut sauce, for example, might have peanut residue on a kitchen utensil as a result of improperly cleaning.
Allergens like dust and pollen are hard to avoid. Frequently cleaning household surfaces and clothing can help. Furry pets can carry allergens in their coats, so bathing them regularly can keep allergies at bay.
Investing in an air purifier with a HEPA filter may offer relief from airborne allergens. Regularly changing air-conditioning filters and keeping windows closed will reduce the amount of pollen that enters the home.
The allergy medications in this article are available online.