Hay fever

Summary hay fever or allergic rhinitis

If the beginning of spring is seen by many as the return of beautiful days, for others it is a sign of discomfort. The cause of the torment is hay fever (pollinosis or pollen allergy), an allergic rhinitis induced by pollen from trees (see photo), grasses and various herbaceous plants, dispersed by the wind. Symptoms are: burns, redness, eye swelling and lacrimation, sneezing, abundant nasal obstruction or dripping, intense itching.

The onset and severity of hay fever symptoms depend on the amount of allergens in the air and the person’s degree of sensitization. 50% to 90% of people who suffer from hay fever have a family history of allergies (genetic predisposition).

The frequency of hay fever varies according to regions, seasons and climatic conditions. Allergic rhinitis is a serious public health problem worldwide, due to the number of people affected, the impact on their quality of life and the costs it generates for society.

Hay fever and sensitization to pollen allergies increase during childhood and peak during adolescence. Pollution is increasingly being considered as one of the causes or triggers, although this is still disputed.

Depending on the severity of the symptoms, a therapy in stages can be proposed and can/should associate the loss of allergy (generally difficult), pharmacological treatment and immunotherapy (or specific, injectable and sublingual desensitization):

– chromones, molecules that prevent the release of histamine and act on runny nose and discomfort. They are well tolerated but their brief action makes it necessary to administer them several times a day.

– antihistamines, which inhibit the action of histamine and are effective on most symptoms of allergic rhinitis. First-generation antihistamines cause drowsiness, while newer ones are better tolerated.

– local corticoids have an anti-inflammatory action and also act on nasal obstruction.

– local decongestants can be used to decrease the obstruction of the nasal bronchi, but they should not be administered for many days.

Desensitization consists of administering increasing doses of the allergen until the organism becomes accustomed to it. The duration of desensitization is 3 to 5 years. This solution is only used when the gene caused is intense and long (several weeks). It is therefore useless to do it if hay fever only occurs a few days a year.


Hay fever, also called allergic rhinitis, affects the nasal cavity and is caused by pollen particles.

To be more precise, allergic rhinitis is more widespread than hay fever and can be caused by many different allergens. One can suffer from allergic rhinitis if you are allergic to dust, for example.

Hay fever is a form of allergic rhinitis caused by pollen particles. Hay fever can occur at different times of the year, depending on the type of pollen you are allergic to.

This pollen can come from trees (birch, hazel…), from grasses (hay, plantain…) or from other plants (nettle, sagebrush…).

It is worth remembering that pollens (photo) are the seeds that allow plants to reproduce, and are mainly transmitted in spring and summer.

Thus, hay fever occurs mainly in spring, summer and autumn. Each plant has a different pollination period. People who are allergic to birch pollen, for example, suffer from hay fever during these months only.

By observing the times when an allergic person suffers from hay fever, one can identify the responsible tree or grass (grass) and avoid exposure to these allergens as much as possible. The pollination calendar can give a clear indication of the pollination season for trees, flowers and grasses. There may be slight modifications to dates, as plant development is highly dependent on climate. So when the winter is mild, pollination can start earlier. Note that in a huge country like Brazil, there are naturally large differences between regions, such as southern Brazil, which is perhaps the region most affected by seasonal allergies because it has very different seasons.

In Portugal, the seasons are well defined and spring is the time of year with the highest risk of hay fever cases.

Also note that people suffering from hay fever are generally more sensitive and therefore more exposed to colds, flu and sinusitis. That is why there is a difficulty in making a good diagnosis based only on the symptoms, which are very similar.


In industrialized countries, about one in five people are affected – double the number 30 years ago – and this prevalence is constantly increasing. Hay fever or allergic rhinitis is a frequent condition.

Epidemiological studies suggest that in the European Union, 10 to 25% of people between 15 and 50 years old suffer from pollen allergic rhinitis (hay fever).

People between 15 and 40 years old are most affected by allergic rhinitis. People usually start their “allergic history” in their teens, although it is possible to start hay fever at any age, more rarely from the age of 40.

The frequency of hay fever varies between regions, seasons and weather conditions.

In the United States, 8.2% of the American population suffers from allergic rhinitis (in English: seasonal allergies ), according to the National Center of Health Statistics , statistics cited in early 2019 by Prevention magazine .


Hay fever is caused by an allergy to pollen, allergies are an exaggerated reaction of our immune system to substances classified as harmless.

Once pollen comes into contact with the nasal mucosa, an allergic reaction begins, mediated by IgE, which is a type of immunoglobulin of the immune system. These IgE recognize these pollen particles as pathogenic agents, although this is not the case. A cascade of reactions is activated through the allergy neurotransmitter, histamine. Then there is inflammation of the mucous membranes (nose and/or eyes), watery eyes, sneezing and a runny nose (excess nasal discharge).

But for that, it takes several moments of contact between the pollen particles and the IgE. Thus, it may be several years before a person becomes allergic to a particular type of pollen.

Also note that 50% to 90% of people who suffer from allergic rhinitis have a family history of allergy (genetic predisposition).

The rise in the number of cases of hay fever in the western world is blamed on air pollution and an overly hygienic lifestyle.

It is estimated that between 5 am and 10 am the concentration of pollen from trees (birch, etc.) is the highest.

people at risk

People at risk of developing hay fever in their lifetime are:

– People living in industrialized countries;

– People who have at least one parent suffering from an allergy (hay fever, eczema or others);

– People between 15 and 40 years old;

– Male people.

– Children who have suffered or suffer from food allergies

People who live in industrialized countries
It is not so much the climate that causes the onset of seasonal allergic rhinitis, but the western lifestyle. It seems that hay fever develops more easily in the West, where there is a hunt for microbes through disinfection and excessive hygiene, which makes the immune system more sensitive to molecules, even if they do not pose a danger. This may seem paradoxical, but it is one of the explanations for the exponential increase in the number of hay fever cases. Pollution is a second explanation for this.

People who have at least one parent who suffers from an allergy (hay fever, eczema or other)
We call these people having an allergic terrain. Allergy can be hereditary. Note that the parents may not have hay fever, they may simply suffer from another allergy and thus pass on the genetic predisposition to their children, who may develop another allergy, in this case hay fever.

People aged between 15 and 40 people
Seasonal allergies can appear at any age, but most often appear in adolescence and rarely after age 40. There are people who develop allergies after the age of 40, but these often begin their allergic history much earlier. All younger children can also develop hay fever, but it is rare. However, it is increasingly common due to increased air pollution.

Males are more likely to develop seasonal allergic rhinitis (hay fever).

Children who have suffered or suffer from food allergies
According to a study published on August 20, 2016 in the journal BMC Pediatrics , children with food allergies are at a higher risk of developing allergic rhinitis. About 35% of children diagnosed with food allergy currently suffer from allergic rhinitis or will develop it, the risk increases even more when the number of foods that cause allergy is greater. The proportion of 35% is double that observed in the general population (without food allergy).


If the symptoms appear every year during spring and summer, times when the concentration of pollen in the air is very high, it is probably a seasonal allergy, that is, hay fever. If, however, the symptoms persist throughout the year, it is a perennial allergy , probably due to the presence of pets with fur (dogs, cats, etc…).

Hay fever symptoms

The symptoms of hay fever are easily identified, they usually appear together, that is, in the same period of time (which differs from the seasonal flu, whose symptoms tend to appear one after the other):

– Sensation of stuffy nose and intense itching, clear and liquid coryza, and often in abundance.

– The eyes become irritated and red, swell and fill with tears: this is called conjunctivitis.

– Common and intense sneezing.

– The throat becomes irritated and painful.

– Cough is sometimes present

In addition to these symptoms, a feeling of tiredness and headaches may appear , which makes the patient feel sicker.

In the most serious cases, there may be difficulty breathing and even asthma attacks (see a doctor immediately).

Hay fever can increase the risk of developing other allergic diseases such as asthma or eczema.

Notes on Hay Fever Symptoms

– It is worth mentioning that the symptoms are directly proportional to the concentration of pollen in the air, that is, on sunny and windy days, as well as in flowering periods, the symptoms will be stronger.

In contrast to rainy days, when symptoms are greatly reduced.

– Hay fever and the sensitization process of pollen allergies increases during school age and peaks during adolescence.

– On average, symptoms of hay fever appear by age 6.

– The duration of hay fever symptoms usually varies between 6 and 8 weeks.

Difference between hay fever and rhinitis (nasal congestion)

Here are some key differences between rhinitis and hay fever.


Diagnosis of hay fever is based primarily on the set of very characteristic symptoms evidenced in the medical history (see: hay fever symptoms). The doctor, checking the beginning and end of the symptoms (months of the year) can identify the allergen or allergens responsible for seasonal allergic rhinitis, according to the pollination season of the trees or grasses.

From this it is possible to confirm the diagnosis by performing a skin test. If this is not enough, a blood test can be performed to check for the presence of specific IgE for the suspected allergens.

skin test

Skin testing involves the subcutaneous application of suspected allergens. As a positive control, the doctor will apply a histamine solution and as a negative control, he will apply a sodium chloride solution. These two control solutions must have known and accurate concentrations. It is essential that four days before the skin test, any antihistamine medication (hay fever medication) is discontinued. Antihistamines block the allergic reaction and the doctor will not be able to identify the allergens.

The skin test is very quick to perform. The reading of the results is done fifteen minutes after the applications. However, the test is very sensitive. Thus, in about a fifth of cases, the person has a reaction to the test, but does not develop an allergic reaction when exposed to the allergen in question. Therefore, it is recommended that the blood dosage of specific IgE be performed.

Specific IgE dosage

This dosage is done through a blood test. The presence of specific IgE to different allergens is sought. With each contact with an allergen, the body produces specific antibodies, the famous IgE. IgE differ from one allergen to another.

It is important to diagnose hay fever in order to take good care of the patient and give him the right medication to make his life more comfortable: avoid repeated sneezing and watery eyes, which are very annoying.

Researching the responsible allergen is important, as this way you can avoid allergic reactions, by avoiding them, for example. In cases where it is not possible to avoid them, the allergist may suggest desensitization treatment, a treatment based on knowledge of the allergen responsible for allergic rhinitis (seasonal or not).


Hay fever itself is not a serious illness. It is a disturbing disease and is constantly increasing in prevalence. In everyday life, the act of driving can become dangerous for highly allergic people, due to repetitive sneezing and tearing. Although researchers have been able to develop anti-allergy medications, these medications can still cause drowsiness in sensitive people. Care is needed.

The main complications found in hay fever are:

– Changes in sleep, sleep disturbances

– Decreased quality of life

– Development of allergies to other pollens and allergens (pet dander, dust, dust mites, food,…)

– Development of chronic rhinitis

– Development of allergic asthma that can progress to chronic asthma

– Development of benign tumors in the nasal cavity (nasal polyps)

– Anaphylaxis

Sleep changes, sleep disturbances

In hay fever, the symptoms are so irritating that they can get in the way of healthy, restful sleep. The allergic person gets tired but cannot sleep as they wake up often because of sneezing and itchy nose/eyes.

This consideration is also valid for the decrease in quality of life in general.

Development of allergies to other pollens and allergens (pet dander, dust, dust mites, food, …)

In allergy, the immune system tends to overreact to other allergens as well. The allergy develops and gains ground. In terms of food, for example, we can develop cross allergies.

Development of chronic rhinitis

Seasonal rhinitis can become chronic and no longer limited to the seasons. The person can suffer from allergic symptoms all year round.

Development of allergic asthma that can progress to chronic asthma

The development of allergic asthma is the most common complication of hay fever. This complication can affect one in three allergic people. Controlling allergic asthma is the administration of anti-asthmatic medications such as bronchodilators and/or cortisone to reduce the inflammatory process and improve breathing.

nasal polyps

Nasal polyps consist of benign growths in the nasal cavity and/or sinuses. They obstruct the nasal cavity and cause hypersecretion. Nasal polyposis is treated with cortisone-based medication or surgery to remove it.

Anaphylaxis (anaphylactic shock)
Allergic reactions, such as hay fever, sometimes go beyond a typical allergic reaction to become a generalized allergy, which can result in a drop in blood pressure or even loss of consciousness. This type of severe allergy is called anaphylaxis and often requires emergency treatment (for example, for those who are severely allergic to bee stings, they should always carry an adrenaline-based injection with them).


We can distinguish several types of treatments to cure hay fever:

1. Medicines for hay fever

There are medications that aim to reduce the symptoms of hay fever, but do not cure the cause (hypersensitivity to pollen).

The best-known and most effective active ingredient, available over the counter in pharmacies, is a medicine that contains cetirizine.

This molecule is part of a modern class of antihistamines (with a lesser sedative effect), available in pills and drops.

There is also another type of modern and effective antihistamines, which are loratadine-based drugs.

Desloratadine is also used to treat hay fever and allergies.

You can also use nasal spray, containing vasoconstrictors, to unclog the nose or eye drops in associated conjunctivitis.

Apparently the active principle cromoglycic acid can exert a preventive effect on hay fever, this can be found in the form of eye drops or nasal spray.

The doctor may also recommend corticosteroid-based medications in the form of a nasal spray or, in more severe cases, oral treatment (in the form of pills).

To find out about brands, dosage and other drugs and active ingredients (anti-leukotrienes…), please contact your doctor or pharmacist.

Comments :

– Do not consume alcohol with this medicine

– Cetirizine can cause drowsiness, so be careful when driving a vehicle.

2. Desensitization – Prevention of hay fever

Note that a therapy that acts preventively and is based on desensitization (or hyposensitization) to pollen, can allow the body to progressively get used to the allergens until there is no longer an allergic reaction. It is estimated that this desensitization method usually lasts 3 to 5 years and averages over 200 injections done in the doctor’s office (however, newer therapies may only allow for three injections, more info in latest news). This therapy should only be considered when the inconvenience is intense and long (several weeks). It is therefore unnecessary to perform desensitization when you are subject to hay fever for only a few days a year. Furthermore,

Talk to your doctor, he can help you.

Desensitization is questioned by some physicians who believe this method is useless and has never been scientifically proven to be effective.

3. Alternatives

There are also treatments based on natural supplements, such as vitamin C (1 gram, 3 times a day of vitamin C, while there are symptoms of hay fever), which has an antioxidant effect on the cells of the respiratory tract, vitamin B5, which is a nasal decongestant, omega-3 fatty acids , which are found in fish fat and reduce throat inflammation.

Although modern medications are more effective, dietary supplement remedies can greatly alleviate symptoms during the most critical periods.

– Depending on your beliefs, you can also try homeopathy, in addition there are different types of remedies, ask your pharmacist.

4. Anaphylactic shock 

If you have been allergic to stings (eg wasp stings) in the past, your risk of anaphylaxis is greater. In this case, the allergic reactions are very violent and sometimes provoke an anaphylactic shock, which can lead to death if the patient is not treated quickly. It is advisable to know how to use these adrenaline pens. Close people must also be aware in order to react quickly. In addition, it is important to regularly check the expiration date on your adrenaline pen. These usually have relatively short expiration dates.

Herbal medicine

The following medicinal plants can have a positive effect on the treatment of hay fever:

– butterbur   (Petasites hybridus), to be taken in pills [would have the same effectiveness as cetirizine-based medicines].

– nettle leaf , to be used as an infusion, prevents sneezing, stuffy nose and itching.

– Chamomile , which should be used as an infusion, helps alleviate nasal inflammation (moderate effectiveness).

For more information about plant medicine, which is often used in addition to other treatments, talk to your doctor or pharmacist.

Essential oils can also help prevent hay fever from starting or ease symptoms. Tarragon essential oil is very effective in preventing the onset of seasonal allergic rhinitis. Before the onset of allergic symptoms, during the pollination period, take a drop of tarragon essential oil placed on a neutral tablet or a little honey. This must be repeated three times a day.


Avoid going out when the air is full of pollen (especially in spring to early summer, especially in southern Brazil and Portugal, places that have very distinct seasons).

– Go outside during or immediately after it rains, as the concentration of pollen in the air is lower at these times.

It is usually in the morning, especially before 10 am, that the air is most loaded with pollen, so avoid going out early in the day to practice outdoor activities.

– Always wear sunglasses during flowering periods (this helps to avoid conjunctivitis).

– Sleep with windows closed to prevent pollen from entering your room (especially during the night).

– Choose to go to regions with less pollen during your vacation, such as mountains or seaside.

– Remove carpets and curtains from the house (if possible), because they attract pollen, dust and dander.

– Wash your house at least once a week with wet cloths.

– If you drive, watch out! The effect of the allergy itself or certain allergy medications can cause drowsiness, and if you feel very tired, don’t drive!

– Wash sheets and pillowcases at least once a week, as pollen is deposited easily.

– It is recommended to wash the hair (especially if they are long) to remove traces of pollen. Hair tends to accumulate different types of pollen. Try washing your hair right before going to bed.

– Avoid contact with animal hair (they can carry pollen).

– Consult a doctor if you have a fever, headache, or a yellow or green nasal discharge (these are symptoms of sinusitis) or if you have difficulty breathing (this could be an asthma attack).

– Only use your wipes once.

– Make nasal washes with salt water.

– In the car, turn off the air intake (including the air conditioning) or install a pollen filter.

– Do not hang clothes on the line, they can carry pollen.

– In your home, install a particulate filter (a-High Efficiency Particulate Air or HEPA) in your heating and ventilation system. Change the filter regularly (eg once a month).

– Possibly go out with a pollen mask, especially if you are in a place with a lot of pollen.

Jeanne Kenney
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I’m a stylist trainer, a content creator, and an entrepreneur passion. Virgo sign and Pisces ascendant, I move easily between my dreams, the crazy world I want, and my feet on the ground to carry out my projects.

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