What allergy medicine works best for itchy eyes
Signs and symptoms of SAC and PAC are the same, but they differ in the onset and duration of symptoms, and specific allergen to which the patient is sensitive. Seasonal allergies are triggered by circulating aeroallergens such as tree, grass, and weed pollens. Symptoms will fluctuate throughout the year, commonly causing exacerbations during times of high pollen counts, such as spring and summer, and during windy and dry weather conditions.
Patients who own PAC will experience symptoms that persist throughout the year, owing to continuous exposure to perennial allergens commonly including dust mites, animal dander, and feathers.4,10 Numerous patients who own PACalmost 79%will also experience a seasonal exacerbation.11
Patients will typically present with bilateral eye symptoms, including red, itchy, and watery eyes; pruritus is considered the hallmark symptom. The itch may be more aggravating in the nasal quadrant of the eye, ranging from mild to severe.
The discharge is generally watery but may contain a little quantity of mucus. There may also be some mild chemosis, or conjunctival swelling, associated with AC. This prominent swelling and mild redness often gives the conjunctiva a pinkish or milky appearance. Lid edema may also sometimes happen. Although symptoms are generally bilateral, the degree of involvement may not always be symmetrical.3,
When evaluating a patient with ocular complaints, it is significant to recognize when a referral is necessary. Some useful questions can assist the pharmacist distinguish AC from other possible causes (Table 1).
If the patient does not complain of itch, a diagnosis of AC is highly unlikely.
However, if a patient is complaining about severe itching, this could be indicative of VKC or AKC, which should immediate a referral. Patients who should immediately be referred to a specialist include those who use contact lenses; those who own experienced trauma to the eye; those with any sign of vision changes including the onset of floaters and diplopia; those who experience severe ocular pain and/or sensitivity to light; and those who are also experiencing any systemic symptoms along with their ocular complaints.4,12,13
AC is an inflammatory response resulting from exposure of the ocular conjunctiva to airborne allergens, including pollen, animal dander, and other environmental allergens.7 The term is used to describe a variety of ocular allergies.
Seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC) are the two most common forms of AC, representing more than 95% of ocular allergies; of the two, SAC is more prevalent.8,9 These are both associated with an immunoglobulin Emediated hypersensitivity reaction. The more severe chronic forms of AC include vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC), which are both mast cellmediated allergic conditions.4,10 Despite some common allergy markers, AKC and VKC own clinical and pathophysiologic features that are diverse from PAC and SAC. They happen less frequently but are potentially more severe and sight-threatening, necessitating referral to an eye specialist.11
Mast Cell Stabilizers
Although the full mechanism of mast cell stabilizers is not entirely understood, it is believed that they prevent the degranulation of mast cells and prevent the release of preformed inflammatory mediators, providing relief by preventing both the early and late-phase allergic response.
However, these agents own a slow onset of action, requiring up to 14 days to reach maximal efficacy. They are more effective in preventing symptoms and should therefore be used prophylactically.
This class may provide an option for patients who do not tolerate other therapies. Treatment should start 2 to 4 weeks prior to the start of the allergy season. Topical mast cell stabilizers own minimal ocular side effects, with burning and stinging being the most common effects.7,10,15
Topical Antihistamine/Vasoconstrictor Combination Products
Topical decongestants were the first agents approved for the treatment of AC with the discovery of tetrahydrozoline in the s and the approval of the first agent, naphazoline, in Today they are still one of the most common OTC agents used in the management of AC in the absence of medical consultation.
Topical decongestants are effective in alleviating hyperemia but own little to no effect on ocular itching. As such, ocular decongestants were paired with topical antihistamines such as pheniramine and antazoline to assist relieve both the itching and redness.
Topical antihistamines block histamine receptors, relieving ocular itching. The combination of an antihistamine with a vasoconstrictor has been shown to be more effective than either agent alone. These topical medications are appropriate for short-term (not more than 10 days) or episodic use only.
Regular use has been associated with tachyphylaxis and should not be routinely recommended. Other adverse effects include burning and stinging upon instillation, and mydriasis.
In addition, their duration of action is short, requiring frequent istration.4,7,11,15,16
When treating patients suffering from SAC and PAC, goals of therapy include avoidance of allergens, reduction in severity and symptoms, and improvement in quality of life.4 Appropriate management should result in immediate relief and control of symptoms. Based on symptomatology, patients should be treated in a stepwise approach (Table 2).4 Patients should be questioned in order to identify ocular allergens and educated on how to avoid them.
Allergen avoidance measures include checking the pollen count and staying inside when it is high, keeping windows closed, turning on the air conditioning, wearing sunglasses outdoors as a barrier to airborne allergens, avoiding eye rubbing, and using air filters. Application of freezing compresses to the eyes 3 to 4 times per day, using hypoallergenic bedding, and bathing/showering before bedtime may also alleviate symptoms of redness and itchiness.
Application of refrigerated artificial tears may also provide relief; artificial tears provide a barrier and assist improve first-line defense by diluting allergens and inflammatory mediators that may be present on the ocular surface.10,14
If nonpharmacologic measures do not offer adequate relief, pharmacologic agents can be utilized. Pharmacologic treatments include the use of topical antihistamine/vasoconstrictor combination products, mast cell stabilizers, antihistamines with mast cell stabilizing properties, nonsteroidal anti-inflammatory agents, and corticosteroids (Table 3).
Antihistamines With Mast Cell Stabilizing Properties
This dual-acting class of medications is now considered the mainstay of treatment for PAC and SAC. These agents combine the actions of competitively and reversibly blocking histamine receptors in the conjunctiva and eyelids and inhibiting mast cell degranulation. Unlike mast cell stabilizers, these agents provide immediate and sustained relief. Olopatadine has proven superiority when compared with most other agents used in the control of ocular allergy symptoms.
These agents are generally well tolerated and can be used in the long-term treatment of SAC and PAC. The most commonly reported side effects include headache, burning, stinging, and bitter taste.7,10,15