Allergies

What causes allergies?

Allergies happen when the body's immune system reacts to a particular substance as though it were harmful, even though it isn't.

It's not fully clear why this happens, but most people affected have a family history of allergies, or have closely related conditions such as asthma or eczema.

The number of people with allergies is rising every year. The reasons for this aren't well understood, but one of the main theories is that it results from living in a cleaner, germ free environment, which means our immune system has fewer germs to deal with.

It's thought this may cause the immune system to overreact when it comes into contact with harmless substances.

Treating allergies

The treatment for an allergy depends on what you’re allergic to. In many cases your pharmacist will be able to offer advice and treatment.

They’ll advise you about taking steps to avoid exposure to the substance you’re allergic to, and can recommend medication to control your symptoms.

Immunotherapy (desensitisation)

Immunotherapy may be an option for a small number of people with certain severe and persistent allergies who are unable to control their symptoms using the measures above.

The treatment involves being given occasional small doses of the allergen – either as an injection, or as drops or tablets under the tongue – over the course of several years.

The injection can only be performed in a specialist clinic under the supervision of a doctor, as there is a small risk of a severe reaction. The drops or tablets can usually be taken at home.

The aim of treatment is to help your body get used to the allergen so it doesn’t react to it so severely. This won’t necessarily cure your allergy, but it will make it milder and mean you can take less medication.

Treating severe allergic reactions (anaphylaxis)

Some people with severe allergies may experience life-threatening reactions, known as anaphylaxis or anaphylactic shock.

If you’re at risk of this, you’ll be given special injectors containing a medicine called adrenaline to use in an emergency.

If you develop symptoms of anaphylaxis, such as difficulty breathing, you should inject yourself in the outer thigh before seeking emergency medical help.

Read more about the treating anaphylaxis.

Avoiding exposure to allergens

The best way to keep your symptoms under control is often to avoid the things you’re allergic to, although this isn’t always practical.

For example, you may be able to help manage:

• food allergies by being careful about what you eat
• animal allergies by keeping pets outside as much as possible and washing them regularly
• mould allergies by keeping your home dry and well-ventilated, and dealing with any damp and condensation
• hay fever by staying indoors and avoiding grassy areas when the pollen count is high
• dust mite allergies by using allergy-proof duvets and pillows, and fitting wooden floors rather than carpets

Read more about preventing allergic reactions.

Allergy medications

Medications for mild allergies are available from pharmacies on the Pharmacy First Scotland service without a prescription, but always ask your pharmacist for advice before starting any new medicine, as they’re not suitable for everyone.

Antihistamines

Antihistamines are the main medicines for allergies. They can be used:

• as and when you notice the symptoms of an allergic reaction
• to prevent allergic reactions – for example, you may take them in the morning if you have hay fever and you know the pollen count is high that day

Antihistamines can be taken as tablets, capsules, creams, liquids, eye drops or nasal sprays, depending on which part of your body is affected by your allergy.

Decongestants

Decongestants can be used as a short-term treatment for a blocked nose caused by an allergic reaction.

They can be taken as tablets, capsules, nasal sprays or liquids. Don’t use them for more than a week at a time, as using them for long periods can make your symptoms worse.

Lotions and creams

Red and itchy skin caused by an allergic reaction can sometimes be treated with over-the-counter creams and lotions, such as:

• emollients (moisturising creams) to keep the skin moist and protect it from allergens
• calamine lotion to reduce itchiness
• steroids to reduce inflammation (see below)

Steroids

Steroid medications can help reduce inflammation caused by an allergic reaction. They’re available as:

• nasal sprays and eye drops for an inflamed nose and eyes
• creams for eczema and contact dermatitis
• inhalers for asthma
• tablets for hives (urticaria)

Sprays, drops and weak steroid creams are available without a prescription. Stronger creams, inhalers and tablets are available on prescription from your GP.

Preventing an allergic reaction

The best way to prevent an allergic reaction is to avoid the substance that you’re allergic to, although this isn’t always easy or practical.

Below is some practical advice that should help you avoid the most common allergens.

House dust mites

One of the biggest causes of allergies are dust mites, which are tiny insects found in household dust. You can limit the number of mites in your home by:

• choosing wood or hard vinyl floor coverings instead of a carpet
• fitting roller blinds that can be easily wiped clean
• choosing leather, plastic or vinyl furniture instead of upholstered furniture
• cleaning cushions, soft toys, curtains and upholstered furniture regularly, either by washing (at a high temperature) or vacuuming
• using tested allergy-proof covers on mattresses, duvets and pillows
• using a vacuum cleaner fitted with a HEPA (high-efficiency particulate air) filter, because it can trap more dust mites than ordinary vacuum cleaners
• regularly wiping surfaces with a damp, clean cloth – avoid dry dusting, as this can spread dust into the air

Concentrate your efforts of controlling dust mites in the areas of your home where you spend the most time, such as the bedroom and living room.

You can find more information on indoor allergies in the home on the Allergy UK website.

Pets

It’s not the pet fur that causes an allergic reaction. Instead, it’s flakes of their dead skin, saliva and dried urine.

If you can’t permanently remove a pet from the house, you could try:

• keeping pets outside as much as possible, or limiting them to a particular area of the house, preferably an area without carpet
• not allowing pets in bedrooms
• washing pets at least once a week
• regularly grooming pets outside
• regularly washing all bedding and soft furnishings on which a pet has lain
• using an air filter in rooms where you spend most of your time
• increase ventilation with fans, air-conditioning or by opening windows

If you’re visiting a friend or relative with a pet, ask them not to dust or vacuum on the day you’re visiting, as this will stir up the allergens into the air. Taking an antihistamine medicine about an hour before entering a pet-inhabited house can also help reduce your symptoms.

The Allergy UK website has more information about domestic pet allergies.

Mould spores

Tiny particles released by moulds can cause an allergic reaction in some people.

You can help prevent this by:

• keeping your home dry and well-ventilated
• removing any indoor pot plants from your home
• not drying clothes indoors, store clothes in damp cupboards or packing clothes too tightly in wardrobes
• dealing with any damp and condensation in your home
• avoiding damp buildings, damp woods and rotten leaves, cut grass and compost heaps

Food allergies

By law, food manufacturers must clearly label any foods that contain something that’s known to cause allergic reactions in some people. By carefully checking the label for the list of ingredients, you should be able to avoid an allergic reaction.

People with food allergies most often experience an allergic reaction while eating out at a restaurant. You can avoid this by:

• not relying on the menu description alone (remember, many sauces or dressings could contain allergens)
• communicating clearly with the waiting staff and asking for their advice
• avoiding places where there’s a chance that different types of food could come into contact with each other, such as buffets or bakeries
• let restaurant staff you know your dietary requirements, including how severe your food allergy or intolerance is
• always check what allergens are in the dish even if you have eaten it before, as recipes and ingredients can change

Remember, simple dishes are less likely to contain “hidden” ingredients. If you’re not sure about a dish, don’t risk it

Read more about living with a food allergy and advice from the Food Standards Agency on food allergen labelling.

Hay fever

Pollen allergies – more commonly known as hay fever – are caused when trees and grasses release pollen into the air. Doctors often call hay fever allergic rhinitis.

Different plants pollinate at different times of the year, so the months that you get hay fever will depend on what sort of pollen(s) you are allergic to. Typically, people are affected during spring (trees) and summer (grasses).

To help keep your hay fever under control, you can:

• check weather reports for the pollen count and stay indoors when it’s high, if possible
• avoid drying clothes and bedding outside when the pollen count is high
• wear wraparound sunglasses to protect your eyes
• keep doors and windows shut when possible
• shower and change your clothes after being outside
• avoid grassy areas, such as parks and fields – particularly in the early morning, evening or night, when the pollen count is highest
• if you have a lawn, try asking someone else to cut the grass for you

Insect bites and stings

If you’ve ever suffered a bad reaction to an insect bite or sting, it’s important to take precautions to minimise your risk.

When you’re outdoors, particularly in the summer, you could:

• cover exposed skin
• wear shoes
• apply insect repellent
• avoid wearing strong perfumes or fragrances, as these can attract insects

Preventing severe allergies (anaphylaxis)

If you’re at risk of experiencing a severe allergic reaction (anaphylaxis), make sure you carry two adrenaline auto-injectors with you everywhere.

Wearing a MedicAlert or Medi-Tag medallion or bracelet can make others aware of your allergy in an emergency.

Consider telling your teachers, work colleagues and friends, so they can give you your adrenaline injection in an emergency, while waiting for an ambulance.

Read more about preventing anaphylaxis.

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