Antihistamines are a class of drugs primarily used to relieveallergies.
Antihistamines may also be useful in treating motion sickness, nausea, sinusitis, and eczema.
Among the conditions they most commonly treat are allergic rhinitis, allergic conjunctivitis, and hives.
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It canoccur seasonallyor year-round, due primarily to tree or grass pollens.
Oral antihistamines can generally improve hay fever symptoms within an hour or two.
Allergic Conjunctivitis
Many of the same allergens that cause hay fever can also causeallergic conjunctivitis.
an allergic reaction involving the covering of the eye (known as theconjunctiva).
Oral antihistamines can help treat symptoms of eye allergies.
In some cases, the cause of an outbreak is unknown.
Oral antihistamines are the main treatment for hives.
Older-generation antihistamines may help you sleep more soundly.
Topical antihistamines, present in many over-the-counteranti-itch creams, should not be used with oral antihistamines.
Certain ones, such as Benadryl cream, have been known to triggercontact dermatitiswhen taken with its oral version.
Other Uses
Antihistamines are used for the treatment of other allergic conditions.
Not all antihistamines work equally well for all allergic conditions.
They can also diminish your ability to operate motor vehicles or heavy machinery.
Of the second-generation antihistamines, Allegra is the only one that is truly considered to be non-sedating.
Certain antihistaminesmay also cause weight gain.
Summary
Antihistamines are used to treat allergies.
They may also be useful in treating motion sickness, nausea, sinusitis, and eczema.
This includes the risk of dependency if antihistamine eyedrops are overused.
An allergist can perform tests to see which allergens you are reacting to.
Frequently Asked Questions
Antihistamines are most often used to treat allergy symptoms.
Antihistamines work by blocking the action of histamine.
Antihistamines can be either H1 blockers or H2 blockers, named for the histamine receptor they block.
Antihistamines generally have a low risk of abuse.
Withdrawal may occur once the drug is stopped.
Scadding GK.Optimal management of allergic rhinitis.Arch Dis Child.
2015;100(6):576-82. doi:10.1136/archdischild-2014-306300
Church MK, Church DS.Pharmacology of antihistamines.Indian J Dermatol.
2004;54(503):412-4.
PMID: 15186559
Rathi VM, Murthy SI.Allergic conjunctivitis.Community Eye Health.2017;30(99):S7S10.
American Academy of Asthma, Allergy & Immunology.Antihistamines and weight gain.
2018;132(2):105-10. doi:10.1017/S002221511700192X.
