Overview

Grass allergy is an allergic reaction to pollen from certain types of grass. This condition is usually known as hay fever or allergic rhinitis.

Grass is one of many other allergens that can be a harmless substance that the body misidentifies as harmful, causing this allergic reaction. It is considered a seasonal allergy as grass pollen will trigger people during late spring and summer, causing symptoms to arise at similar times each year.

It’s important to learn about the causes of this allergy, so that they can be avoided and managed by treatments to overcome its effects; especially, since it tends to affect the day-to-day lives of people during work or school. This article will go into these aspects about grass allergy in more detail.^1,2

Causes of grass allergy

Grass allergy can occur when pollen gets released from grasses. It’s more commonly experienced in areas with a greater presence of grass. While there are hundreds of grass types, only a few of these trigger allergy symptoms.^3,4 These include:

• Bahia grass
• Bermuda grass
• Fescue grass
• Johnson grass
• Kentucky bluegrass
• Timothy grass^3,4

Grass is a harmless substance, but the body can recognise it as a harmful allergen resulting in overreaction and activation of the immune system. As a result, immunoglobulin E (IgE) antibodies are produced in response to the allergen which binds to specific cells, known as mast cells.

Once activated, mast cells release chemical substances called inflammatory mediators, such as histamine, which trigger an allergic reaction and lead to the onset of symptoms.^1,3

Genetic factors have been seen to influence allergies as they run in families, but other factors, such as air pollution and cigarette smoke, can contribute as well.³

Symptoms of grass allergy

It is common for grass and flowers to release pollen at greater levels as the weather becomes warmer. Symptoms of grass allergy are commonly experienced at this time, and may become worse.²

The following are common symptoms of grass allergies:

• Sneezing
• Runny or congested nose 
• Headaches
• Dark circles under eyes
• Itchy, red, watery and swollen eyes (allergic conjunctivitis) 
• Itchy nose, mouth or throat
• Mucus running down throat (postnasal drip)
• Red, itchy skin (allergic/contact dermatitis)
• Wheezing, coughing^1,2

Most people experience these symptoms in the upper respiratory tract, but they can eventually spread to the lungs, causing allergic asthma and more severe symptoms in some people.³

Some of these less common grass allergy symptoms include:

• Weak and tiredness
• Asthma attacks
• Inflammation of the sinuses (sinusitis)
• Difficulty breathing, shortness of breath³

Diagnosis of grass allergy

To diagnose an allergy to grass, healthcare professionals will ask patients about symptoms they have been experiencing as well as other conditions they may have, such as asthma.^1,2

In order to confirm the diagnosis of grass allergy, physical tests are performed, including:

• Skin prick test - Samples of various grass allergens are applied to the skin either on the arms or back using a needle. After 15-20 minutes, if the area becomes red, itchy, and a raised bump forms, it indicates that there is an allergic reaction to the specific grass allergen
• Allergy blood test - Blood samples are tested in the lab to assess the immune system's response to specific grass allergens, by measuring the levels of IgE antibodies in the bloodstream^1,2

Treatment and management of grass allergy

After diagnosis, healthcare professionals will suggest treatment options based on the severity of the allergies triggered by grass allergens. Medications can benefit those suffering from grass allergies by reducing and relieving symptoms. Some of these medications are:

• Steroids (corticosteroids) - Reduce inflammatory responses, providing relief for nasal stuffiness and runny nose. Available as nasal sprays and inhalers. Examples include fluticasone, budesonide, triamcinolone and mometasone
• Antihistamines - Block the effects of histamine that gets released from mast cells during an allergic response, providing relief for sneezing, itching and runny nose. Available as tablets, eye drops, nasal sprays and inhalers. Examples include cetirizine, loratadine, fexofenadine and levocetirizine
• Chromones (mast cell stabilisers) - Prevents histamine from being released from mast cells which reduces allergic and inflammatory responses in the body. Available as nasal sprays. Examples include cromolyn sodium, nedocromil sodium and ketotifen
• Leukotriene receptor antagonists - Block the action of leukotrienes which are chemical messengers that lead to an inflammatory response in the airways. Examples include montelukast, zafirlukast and pranlukast
• Decongestant nasal sprays - Provide a short term relief of congestion in the nose and sinuses. Available as a tablet or nasal spray. Examples include Afrin, Neo-Synephrine and Sudafed^1,2,3,5

Symptoms can be relieved by taking any one of these medications on its own, but they are more effective when taken together. As a first line of treatment, corticosteroids are usually recommended. 

However, if they aren’t found to be effective, it may be necessary to combine them with another medication like antihistamines, for example, fluticasone and azelastine.

There are a few common side effects associated with taking these medications, including:

• Headaches
• Tiredness/drowsiness
• Increased blood pressure 
• Nasal irritation/nosebleeds

It's important to check with your doctor if you are pregnant, breastfeeding, or have another health condition, before taking these medications.

The following non-drug alternatives can also relieve symptoms, but they don't provide the same benefits as the medications:

• Saline (salt water) nasal spray
• Nasal washes (nasal irrigation)³

A long-term treatment known as allergen-specific immunotherapy (desensitisation) is a vaccination that can be used for those allergic to grass as well. Usually it is used when anti-allergy drugs have not worked to treat grass allergy in people.

To achieve an allergen specific tolerance by this, people are exposed to small amounts of the grass allergen regularly, either by injecting it under the skin or by placing it under the tongue. It is recommended to maintain this for at least three to five years to avoid the allergic reaction caused by certain varieties of grass from returning.^3,6

Prevention of grass allergy and lifestyle adjustments

People can’t avoid allergens completely, but symptoms can be reduced by limiting exposure to them. Pollen that is released from grass is small particles that float in the air that can easily enter the nose and eyes. To avoid this:

• Close doors and windows during grass pollen levels are high
• Stay indoors on dry, windy days
• Avoid outdoor activities during the early morning when pollen levels are at its highest
• Use a dehumidifier to reduce indoor humidity
• Avoid hanging laundry outside as pollen can stick to it
• Avoid mowing the lawn
• Avoid touching your face or rubbing your eyes/nose when outside
• Wash hands after being outside
• Wear masks, hats and sunglasses when outside
• Shower and change clothes after being outside to remove any pollen^1,2,8

In terms of grass allergy symptoms, following these prevention strategies can help lower the risk a little, but according to research it will not make much of a difference.⁷ Grass allergy doesn’t usually lead to serious health conditions, but a healthcare professional should be seen for instances of asthma or a sinus infection. Also, living with these allergies can impact the day-to-day lives of people, affecting:

• Quality of life - Allergy symptoms can affect work, school and outdoor-related activities
• Mental health - Allergy symptoms can interrupt sleep leading to anxiety and lack of energy

A healthcare professional should be visited in these cases too, as they can help by recommending treatment to help them everyday.²

Summary

Grass allergy is a common seasonal condition that typically occurs during the summer months and can affect daily life. It often causes symptoms such as a runny nose, red and itchy eyes, amongst others. However, these symptoms can be effectively managed with proper diagnosis and treatments such as medications, immunotherapy, and avoidance strategies. By understanding the causes of grass allergies, individuals can take steps to reduce their impact on health and well-being.