Causes & symptoms of seasonal allergies

The seasons come and go, and so do seasonal allergies. Some people may just experience one symptom while others may experience several.

Meanwhile, some seasonal allergy sufferers may suffer for just a few weeks of the year; and some, for several months at a time.

There are all sorts of variables involved with seasonal allergies, ranging from occurrence to severity.

This article explores seasonal allergies – what the main symptoms are and what you can do to help ease them.

What are seasonal allergies?

Seasonal allergies, like other types of allergies, develop when the body’s immune system overreacts to something in the environment.

More commonly known as hay fever and also referred to as allergic rhinitis, seasonal allergies can be triggered during the spring, summer or autumn at various times when certain plants pollinate.¹

Hay fever is an extremely common condition and is estimated to affect around 1 in every 5 people in the UK.²

It tends to be triggered when outdoor moulds release their spores, and trees, grasses and weeds release tiny pollen particles into the air to fertilise other plants.

And, as we all know, this can happen all-year round, hence the reason why it’s possible for people to experience hay fever symptoms more than just during the summer-time.

What causes seasonal allergies?

People suffer from seasonal allergies if they are allergic to the allergens that are present in the air around them, the main ones being pollen and mould spores, but they can also extend to other allergens, such as pet hair and dust too.³

Their immune systems react to the allergens by releasing a chemical called histamine into the bloodstream to defend against them. It's the release of these chemicals that causes allergy symptoms.

The weather and temperature can significantly influence pollen levels, with mild winters causing plants to pollinate earlier than usual, triggering people’s allergies sooner.

Meanwhile, rain can lead to sudden plant growth spurts. This creates increased in mould, which is another common allergen, alongside pollen.

1. Tree and grass pollens thrive during cool nights and warm days.
2. Mould grows quickly in heat and high humidity.
3. Pollen levels tend to peak in the morning.
4. Rain washes pollen away, but pollen counts can rise after rainfall.
5. When there’s no wind, airborne allergens are grounded.
6. On windy and warm days, pollen levels rise.

Summary

• Seasonal allergies, like other types of allergies, develop when the body’s immune system overreacts to something in the environment
• These allergies are more commonly referred to as hay fever or allergic rhinitis
• Common triggers include pollen, mould spores, dust and animal hair

What symptoms can seasonal allergies cause?

Not everybody experiences the same symptoms. It’s possible to have just one symptom or multiple symptoms, and for the severity of these symptoms to change throughout the year.

Hay fever tends to cause cold-like symptoms – some can be mild and some can be severe. They tend to develop the moment you are exposed to an allergen.⁴

Common symptoms include:

• Sneezing
• Itchy sinuses, throat or ears
• A blocked or runny nose
• Watery and/or itchy eyes
• Pressure in your ears and face

What are symptoms of bad allergies?

The symptoms of allergic rhinitis can sometimes improve over time, but this can take many years and it's unlikely that the condition will disappear completely.⁵

It’s also possible for some people to experience more severe symptoms than others, such as these:

• Headaches
• Shortness of breath
• Wheezing
• Coughing

The severity of people’s symptoms can change throughout the year as the seasons change. Many people who have hay fever also tend to have asthma and are more prone to experiencing wheezing.

In some instances, hay fever can also lead to further health issues, such as:

1. Nasal polyps – sacs of fluid that grow inside the nasal passages and sinuses.
2. Sinusitis – an infection caused by nasal inflammation and swelling that prevents mucus draining from the sinuses.
3. Middle ear infections – infection of part of the ear located directly behind the eardrum.

These problems can often be treated with medication, although surgery is sometimes needed in relation to some severe or long-term cases.

Summary

• Not everybody experiences the same symptoms
• Hay fever tends to cause cold-like symptoms – some mild and some severe
• Severe symptoms include headaches, shortness of breath and wheezing

How do you know if you have a cold or allergies?

It can be difficult to know if you’ve got a cold or an allergy because many of the symptoms are the same – i.e. a blocked or runny nose and sneezing.

But there are certain signs you can look out for that can help you identify if you’re suffering from a cold or seasonal allergy.⁶

1. Mucus

When a cold or seasonal allergy first comes on, they tend to be accompanied by clear mucus. If you have a cold, the mucus will become thicker and yellow. But if you have an allergy, it will stay clear and watery.

2. Cough

If you’re coughing up mucus, even if it’s clear, and have a sore throat, then you’re most likely to have a cold. People very rarely get a sore throat if they have an allergy.

3. Eyes

Itchy and watery eyes, as well as swelling, are solely linked to allergies. Colds can make your eyes feel a bit sore, but they don’t tend to impact them beyond that.

4. Longevity

Colds tend to last around three to five days, and up to a week max. Allergy symptoms, especially if you are continuously being exposed to allergens, can last much longer.

However, if you can avoid the allergens, you should instantly start to feel better, which isn’t the case with a cold.

5. Seasonal patterns

Developing a ‘cold’ around the same time of year, every year could be a sign you’ve got a seasonal allergy and not just a cold.

6. Temperature

People’s temperature can rise if they get a cold or the flu, but this is extremely uncommon with allergies. They may increase your temperature a little bit, but nowhere near as much as colds and the flu can.

7. Aches and pains

Allergies tend to make people feel tired and run down, as opposed to colds that can make your muscles and joints ache. People’s muscles don’t tend to ache if they are experiencing allergy symptoms.

3 ways to treat seasonal allergies

You can’t 100% get rid of seasonal allergies, but there are certain things you can do to help ease the symptoms of them.⁷

1. Avoid your allergy triggers

If you are allergic to pollen and mould spores, then limiting how much you’re exposed to your trigger allergens during peak pollen season may help reduce your symptoms. For example, you can try:

• Staying indoors on dry, windy days – the best time to venture outside is after it’s rained, as the pollen will have been washed away
• Removing the clothes you've worn outside – as soon as you get in and have a shower to fully rid yourself of any pollen
• Drying your laundry inside – to avoid it from becoming contaminated with pollen
• Wear a pollen mask – while you do your outside chores, such as gardening

2. Keep a close eye on the pollen levels

Seasonal allergies can get worse when pollen levels are at their highest. If the pollen count is rising:

• Close your doors and windows - at night or any other time when pollen counts are rising
• Avoid outdoor activity - in the early morning when pollen counts are at their highest

3. Use over the counter remedies

There are several non-prescription medications you can try. They include:

• Oral antihistamines - antihistamines can help relieve sneezing, itching, a runny nose and watery eyes
• Decongestants - oral decongestants can provide temporary relief from nasal stuffiness
• Nasal sprays - can ease allergy symptoms and tend to be most effective when you start using them before your symptoms start
• Combination medications - some allergy medications combine an antihistamine with a decongestant for double action
• Sinus rinses - rinsing your nasal passages with saline solution (nasal irrigation) is a quick, inexpensive and effective way to relieve nasal congestion. Rinsing directly flushes out mucus and allergens from your nose

Summary

• It can be difficult to know if you’ve got a cold or an allergy because of similar symptoms
• There are certain signs you can look out for to identify between the two
• It’s possible to reduce your symptoms by taking measures, such as avoiding your triggers, monitoring pollen levels and using over the counter remedies

When to see a GP about your seasonal allergies

If you are experiencing severe symptoms or your hay fever has resulted in you developing other health issues, such as sinusitis or a middle ear infection, speak to your GP or medical professional.

Alternatively, it may be stopping you from getting to sleep or staying asleep or impacting your ability to go about your everyday life as you normally would.

If this is the case, speak to your GP or medical professional about the treatment options available to you.

If it’s not clear what’s causing your seasonal allergy, you may be asked to take part in allergy testing.⁸

The two main allergy tests are: ⁹

• A skin prick test – where the allergen is placed on your arm and the surface of the skin is pricked with a needle to introduce the allergen to your immune system. If you're allergic to the substance, a small itchy spot (welt) will appear.
• A blood test – to check for the immunoglobulin E (IgE) antibody in your blood. Your immune system produces this antibody in response to suspected allergens.

The symptoms of allergic rhinitis do sometimes improve with time, but it can take several years and it's unlikely that it will completely disappear.

Takeaway

Seasonal allergies can last for more than one season, with people experiencing different symptoms as the year progresses.

While it’s not possible to completely get rid of seasonal allergies, it is possible to use treatments to help ease the symptoms and make them more manageable on a day-to-day basis.

The information in this article is for guidance only and is not designed to replace medical advice. If you are experiencing seasonal allergy symptoms that you would like help to ease, speak to your GP or medical professional.

In the meantime, for more insight on allergies read this article, ‘A guide to allergies.’

Last updated: 18 June 2021