What are some common allergies?

Hay fever, or allergic rhinitis, is an allergic reaction to pollen. It most commonly happens in Spring, when plants are releasing their pollen. It can cause nasal symptoms, such as sneezing and a blocked nose, and can also cause allergic conjunctivitis – irritation and watering of the eyes. It affects roughly 5.5 % of the UK population. It can be treated with over-the-counter medications, such as loratadine tablets, cetirizine hydrochloride tablets, beclomethazone nasal spray, fluticasone nasal spray, or sodium cromoglycate eye drops. Wearing sunglasses has also been shown to help with eye symptoms.

Asthma

Asthma is an allergic condition which is common in children and adults. In the UK, approximately 9.4 % of the population suffers from it. The most common symptoms are wheezing and shortness of breath on exertion, caused by the airways tightening and restricting air flow. Sufferers typically also get night time coughing, and symptoms may be worse at night. Asthma is mainly diagnosed by the patient's history, but investigations such as spirometry and peak flow – used to assess breathing ability – can be very useful. Asthma attacks may also occur – these are acute episodes of asthma where the symptoms get worse. The amount of oxygen the sufferer has in their body may become significantly low, the pulse can rise, and wheezing and shortness of breath can become worse. The accessory muscles of respiration, which are muscle groups used when breathing enough air is difficult, may also be used, and this can be seen on the body as movements above, between, and underneath the ribs. Severe asthma attacks may not feature a wheeze, as not enough air is being breathed to create a wheeze. The patient may turn blue and may also become unconscious. However, although symptoms may be extreme during asthma attacks, there may be very few symptoms in between these episodes. Asthma is most commonly treated with inhalers.

Food allergies

Food allergies affect 5 – 7 % of infants and 1 – 2 % of adults in the UK. The most common food allergies are allergies to dairy, eggs, peanuts, tree nuts, shellfish, soya, seafood, and wheat, and the rate of allergies to seeds (especially sesame) appears to be increasing in some countries. Signs and symptoms include angioedema, urticaria, and gastrointestinal problems such as diarrhoea, vomiting, or cramps. Nuts, milk, eggs, and seafood may often cause an anaphylactic shock, which may be fatal. Oral allergy syndrome is a type of food allergy found most commonly in hay fever sufferers, and can cause irritation in the lips, mouth, and throat, and may also cause swelling. If the allergen is swallowed, it can cause further symptoms in the gastrointestinal tract. The main form of treatment against food allergies is avoiding the food substance that causes the allergic reaction. Antihistamines such as chlorphenamine are also useful. EpiPens, used to administer adrenaline, should be used in anaphylaxis.

House dust mite allergy

House dust mite allergy is an allergic reaction to the waste products of house dust mites – small organisms that live in furniture and upholstery. Many house dust mites die during winter, however, modern heating systems have provided a good environment for them to thrive in. The waste proteins can be breathed in and will cause symptoms similar to hay fever, as well as coughing or wheezing, and can aggravate allergic eczema as well. Advice for sufferers involves cleaning any fabric surfaces like bedding or rugs thoroughly and at high temperatures to kill off any house dust mites, and avoiding furnishings which can attract dust (such as fabrics with a long pile – for example, some cuddly toys, knotted rugs). Treatment for the symptoms is similar to treatment for asthma or hay fever

Pet allergies

Pet allergies are allergies to the hair, secretions, urine, or saliva of pets, and can be a nightmare for animal lovers. Symptoms include respiratory symptoms, as well as eye irritation and urticaria / angioedema, or eczema. The best treatment is to remove the pet or avoid contact with any animals you may be allergic to. Also practising good hygiene around the house will help remove any animal allergens from furniture or other surfaces, and thus, carpets and bedsheets should be cleaned regularly and surfaces should be dusted regularly too. You should also wash your hands after touching the animal. Washing the pet or animal regularly has been shown to reduce the allergen levels in the household as well.

There are, of course, more types of allergies. More detail about specific allergies can be found in other articles in this section.

Allergies Guide Index:

• What are allergies?
• What's the difference between allergies, intolerance, and sensitivity?
• Overview of the immune system
• How do allergies happen?
• Who gets allergies?

• What are some common symptoms of allergies?
• What are some common allergies?
• How can I check to see what I'm allergic to?
• What treatment options are available?