How long have allergies been around

In an important breakthrough, exhaustive studies of cases previously dismissed as medical anomalies were demonstrated to be food allergies. The floodgates opened, and as diagnoses surged many medical practitioners derided food allergies as a passing fad. Meanwhile, the production of drugs to treat allergies accelerated.

In , the steroid corticosteroid was successfully used to reduce the inflammation in asthma attacks, and specific anti-allergy products were developed, such as non-biological washing powder that answered growing fears about the enzymes in biological soaps.

Food labeling also became widespread and warnings about potential allergies began to appear. These are found in some of the most sensitive parts of the body, including the skin, blood vessels, and respiratory system. A mast cell contains to 1, granules, each packed with different chemicals, such as histamine, designed to attack antigens. Then in , researchers identified immunoglobulin E IgE , the antibody responsible for most allergic reactions. When someone is exposed to an antigen, peanuts for example, their body produces a specific IgE antibody in a process called sensitization.

People prone to allergies produce disproportionate amounts of IgE that remain dormant until the allergen is detected again; they then go berserk, triggering the mast cells to release their allergy-causing chemicals. Further discoveries followed: blood tests to detect IgE levels; the EpiPen to treat anaphylactic shock; and in , the Nobel Prize in Medicine and Physiology was awarded for work on leukotrienes, which cause asthma and inflammatory responses to antigens.

And so the research continues. Advances are being made in immunotherapy and the management of some symptoms, but a cure for any allergy remains as elusive as ever. We asked some big questions about living a better life. John Bostock in This continues to be one of the most common allergic reactions, affecting approximately 15 million people in the United States.

In the first skin test for allergies was described when a scientist placed pollen into a small cut in the skin and watched for a reaction. Most populations around the world do not get enough vitamin D for several reasons, including spending less time in the sun. In the US, the rate of vitamin D deficiency is thought to have almost doubled in just over a decade. A newer, "dual allergen exposure" theory, suggests food allergy development is down to the balance between the timing, dose and form of exposure.

For example, the development of the allergy antibodies can take place through the skin, particularly through inflamed skin in babies with eczema. But it is thought that eating trigger foods during weaning can lead to a healthy response and prevent the allergy developing, because the gut's immune system is prepared to tolerate bacteria and foreign substances, such as food.

This study led to changes in US guidelines about peanut consumption in infancy. UK parents have been advised to consult their GP first. More like this. The deaths of UK teenagers suffering from food allergies highlights the human impact of this condition, and the importance of clear and accurate labelling. There is currently no cure for food allergy, and managing the condition relies on avoiding the offending foods and on an emergency treatment plan in case of exposure.

But even making an initial diagnosis is challenging. The main way to identify food allergies is for a patient to gradually eat increased amounts of that food under medical supervision. However, this is distressing for children, and has the risk of causing an allergic reaction.

The accompanying tests of their immune systems' reaction can also give a false positive in non-allergic children. At King's College London we have developed an alternative; a blood test which has proved accurate in diagnosing peanut allergy compared with existing methods.

Even following a successful diagnosis, avoiding trigger foods is difficult and accidental reactions are common. Allergen immunotherapy - administering small amounts of the substance - has been shown to reduce the sensitivity of allergic patients and can protect against accidental exposure.

Nevertheless, they are still allergic. Other treatments are being investigated for food allergy, and are much needed. In the meantime, allergies will remain a source of worry and part of daily life for the children and their parents.