Allergy is a disorder of the immune system. Allergens or environmental substances cause allergy. Allergy reactions are acquired, predictable and rapid. Allergy is one of four forms of hypersensitivity and is called type I (or immediate) hypersensitivity. Allergy is characterized by excessive activation of certain white blood cells called mast cells and basophils by a type of antibody known as IgE, resulting in an extreme inflammatory response. Some of the common allergic reactions include asthma, eczema, hives, hay fever, food allergies, and reactions to the venom of stinging insects such as wasps and bees. Severe allergies to environmental or dietary allergens or to medication may some time (or to some persons) result in life threatening anaphylactic reactions and death.
Many allergens that causes allergy are airborne particles like dust or pollen. In such cases, symptoms arise in areas in contact with air, like eyes, nose and lungs. For example, allergic rhinitis, also known as hay fever, causes irritation of the nose, sneezing, and itching and redness of the eyes. Here is the common symptoms of allergy and organs affected:
Swelling of the nasal mucosa (allergic rhinitis).
Redness and itching of the conjunctiva (allergic conjunctivitis).
Sneezing, coughing, bronchoconstriction, wheezing and dyspnea, sometimes outright attacks of asthma, in severe cases the airway constricts due to swelling known as angioedema.
Feeling of fullness, possibly pain, and impaired hearing due to the lack of eustachian tube drainage.
Rashes, such as eczema and hives (urticaria)
Abdominal pain, bloating, vomiting, diarrhea.
If you have an allergy then your doctor will decide on a specific drug regimen. Since every person is different, therfore, treatment for allergy will depend on individual needs. Though there is no cure for allergies, there are several types of medicines available to help ease annoying symptoms like congestion and runny nose. Both over the counter and prescription medicines are available for allergy. These include antihistamines, decongestants, combination medicines, corticosteroids and others. Allergy shots are also options and they gradually increase your ability to tolerate allergens. We've listed common drugs that may be prescribed for allergies.
Allergen triggers immune system which in turn release a substance called histamine, which attaches to receptors in blood vessels causing them to enlarge. Histamine also binds to other receptors causing redness, swelling, itching and changes in secretions. Antihistamine blocks histamine receptors, and prevent allergy symptoms.
Used for years to treat allergy symptoms, antihistamines can be taken as pills, liquid, nasal spray or eye drops. Antihistamine eye drops can relieve red itchy eyes, while nasal sprays are used to treat the symptoms of seasonal or year-round allergies. Common over-the-counter antihistamines medicines include Benadryl, Claritin, Chlor-Trimeton, Dimetane, Zyrtec, and Tavist. Clarinex and Allegra are prescription medicines. Astelin is a prescription nasal spray. Eye drops include Emadine and Livostin.
Decongestants relieve congestion and are generally prescribed along with antihistamines. They are available in nasal spray, eye drop, liquid or pill form. Nasal spray and eye drop decongestants can be used for only a few days because long-term use can actually make symptoms worse. Pills and liquid decongestants may be taken longer safely.
Some examples of over the counter decongestants include Zytec-D, Sudafed tablets or liquid, Neo-Synephrine and Afrin nasal sprays, and Visine eye drops. The prescription decongestants include drugs like Claritin-D and Allegra-D that combine a decongestant with another allergy medicine.
Many a times, your doctor will prescribe a combination of medicines to treat allergy. Some allergy medicines combine both an antihistamine and a decongestant to relieve multiple symptoms. There are also other combinations, such as those between an allergy medicine and asthma medicine and an antihistamine eye drop with a mast cell stabilizer drug.