Mild allergy symptoms

Some people find that the allergy symptoms they experience are always mild. For example, there may be a tingling or itching in the mouth, or a localised rash - nothing more. This is not serious in itself, and may be treated with oral antihistamines. However, in some cases the allergy may become worse over time. It is wise in all cases to make an appointment with the doctor and seek a referral to a specialist allergy clinic.

If there is marked difficulty in breathing or swallowing, and/or a sudden weakness or floppiness, regard these as serious symptoms requiring immediate treatment.

What is the treatment for a severe reaction?

Pre-loaded adrenaline injection kits are available on prescription for those believed to be at risk. These are available in two strengths - adult and junior.

The injection must be given, as directed, as soon as a serious reaction is suspected and an ambulance must be called. If there is no improvement in 5-10 minutes, give a second injection.

Why does anaphylaxis occur?

Any allergic reaction, including the most extreme form, anaphylactic shock, occurs because the body's immune system reacts inappropriately in response to the presence of a substance that it wrongly perceives as a threat.

What exactly is going on?

An anaphylactic reaction is caused by the sudden release of chemical substances, including histamine, from cells in the blood and tissues where they are stored. The release is triggered by the reaction between the allergic antibody (IgE) with the substance (allergen) causing the anaphylactic reaction. This mechanism is so sensitive that minute quantities of the allergen can cause a reaction. The released chemicals act on blood vessels to cause the swelling in the mouth and anywhere on the skin. There is a fall in blood pressure and, in asthmatics, the effect is mainly on the lungs.

Why does adrenaline work?

During anaphylaxis, blood vessels leak, bronchial tissues swell and blood pressure drops, causing choking and collapse. Adrenaline (epinephrine) acts quickly to constrict blood vessels, relax smooth muscles in the lungs to improve breathing, stimulate the heartbeat and help to stop swelling around the face and lips (angioedema).

How do I know if I am at risk from anaphylaxis?

If you have suffered a bad allergic reaction in the past – whatever the cause – then any future reaction is also likely to be severe. If you have suffered a significant reaction to a tiny dose, or have reacted on skin contact, this might also be a sign that a larger dose may trigger a severe reaction. If you have asthma as well as allergies, a referral is particularly important because asthma can put you in a higher risk category. Where foods such as nuts, seeds, shellfish and fish are concerned, even mild symptoms should not be ignored because future reactions may be severe. For a list of NHS allergy clinics, GPs can refer to the website of the British Society for Allergy and Clinical Immunology: www.bsaci.org

What are the most common causes of anaphylaxis?

Common causes include foods such as peanuts, tree nuts (e.g. almonds, walnuts, cashews, Brazils), sesame, fish, shellfish, dairy products and eggs. Non-food causes include wasp or bee stings, natural latex (rubber), penicillin or any other drug or injection. In some people, exercise can trigger a severe reaction - either on its own or in combination with other factors such as food or drugs (e.g. aspirin).

Fresh fruit allergy may occur in people who are allergic to pollen. This is frequently mild, but a doctor's advice should be sought.

What will an allergy specialist do?

There is no perfect way to measure an individual's potential for a severe allergic reaction, but, in making a diagnosis, an allergy consultant can do several things that will provide clues. Most importantly, the specialist will take a detailed history of previous reactions and other allergic conditions you may have. Valuable information can also be provided by means of skin prick tests and blood tests (R.A.S.T. or CAP assay).

How can I avoid problems?

• Minimise the risk by taking great care and being vigilant. If you are food allergic, read labels like Sherlock Holmes: look for the "hidden" allergen. You can easily recognise a packet of peanuts but may miss the word "groundnuts" in tiny print on the side of a tin of curry sauce, or the Latin term arachis used to signify the presence of peanut in pharmaceutical products.
  
• If you are food-allergic, be assertive about asking for detailed information from manufacturers and supermarket staff.
  
• Be particularly careful in restaurants, where proprietors are under no obligation to list ingredients. Question staff very directly. It may be necessary to speak with a senior manager. Some restaurants have ingredient lists available for you to check. You may wish to telephone the restaurant in advance to ensure your allergy is taken seriously.
  
• Be alert to all symptoms and take them seriously. Reach for the adrenaline (epinephrine) if you think you are beginning to show signs of a severe reaction. Do not wait until you are sure. Even if adrenaline is administered, you will still need to get to hospital as soon as possible. Someone must call an ambulance.
  
• Make sure others in your family know how to administer the adrenaline kit - and when. Do not be frightened of adrenaline. It is a well-understood drug. The dose you will administer has very few side effects, which will pass quickly in any case. However, if you have heart difficulties, discuss these with your doctor.
  
• Develop a crisis plan for how to handle an emergency. Get your allergist or GP to help. Have this written out for family and friends - put it on the bulletin board at home; carry one in your pocket. If a child is the person at risk, make sure his teachers and friends' parents have a copy - along with the adrenaline. Make sure everyone knows where the adrenaline is when you go out, or when you are at home.
  
• Wear a MedicAlert talisman (details: 020 7833 3034).
  
• Be open about your allergy problem with your family, friends and colleagues. It's easy to avoid a Thai, Chinese or Indian restaurant if everyone knows you are allergic to peanuts.
  
  

What should I do if I think I am having a serious reaction?

Follow your crisis plan. These are some key points:

• Is there a marked difficulty in breathing or swallowing? Is there sudden weakness or floppiness? Is there a steady deterioration? Any of these are signs of a serious reaction.
  
• Administer adrenaline (epinephrine) without delay if you believe the symptoms are serious, or becoming serious.
  
• Dial 999 or get someone else to do it.