To have knowledge about allergy and what causes it and what’s the mechanism taking place in the body is important.
Allergy or allergic rhinitis is referred as the inflammation of the nasal mucosa and airways and is characterized by sneezing, watery rhinorrhea, itchy eyes and nose, nonproductive cough and nasal congestion.
An allergic attack may be precipitated by inhalation of an allergen as dust, pollen or animal dander, perfumes etc
Foreign material which causes attack or symptoms interacts with mast cells which are coated with IgE immunoglobulin’s which are generated in response to previous allergen. Mast cells release mediators as histamines, leukotriene which promote bronchiolar spasm and mucosal thickening.
Best over the counter anti-allergic drugs to be used are:
Antihistamine are useful for the management of symptoms of allergy cause due to the release of histamine (sneezing, watery rhinorrhea, itchy eyes)
Ophthalmic, nasal, sprays, tablets, capsules, inhales are available.
Drowsiness and sedation are common side effects which are now being covered up with second generation antihistamines.
Short acting alpha adrenergic agonists are often prescribed along with antihistamines. They are used to constrict dilated arterioles in the nasal mucosa and patent airway flow obstruction is also relieved. Also used to relieve congestion. Rapid onset of action and fewer systemic side effects. Available in pills, sprays, inhalers.
Nasal decongestants cause insomnia, glaucoma, raise in blood pressure, and urinary flow obstruction.
Cromolyn is prophylactically used drugs for intranasal decongestion. Used to cause bronchodilation. Intranasal cromolyn is used in allergic rhinitis particularly when administered before coming into contact with allergen. For best results use should begin 1 to 2 weeks prior to allergen exposure.
Used as monotherapy or in combination doses.
These agents block vagally mediated contraction of airway smooth muscles and secretions. It is not recommended for routine treatment of acute bronchospasm as its onset is much slower.
They do not relieve sneezing or nasal congestion.
Corticosteroids are used to relieve Broncho dilation and relieve inflammation associated with allergies. They are used to treat nasal stuffiness, sneezing, itchy nose/eyes and throat caused due to seasonal or perennial hay fever resulting in reduced inflammation of mucous membrane.
Systemic absorption is minimum and they mainly cause nose bleeding, nasal decongestion, sore throat and candidiasis therefore, should not be inhaled deeply.