Allergic Disease
Allergies occur when the immune system reacts against usually harmless substances in the environment, types of food or drugs (“allergens”). The immune system is extremely complex and so there are many opportunities for things to go wrong. When the immune system reacts against an allergen, an exaggerated, damaging immune response occurs.
Allergic diseases are common and are increasing in prevalence, complexity and severity. They include food, insect and drug allergies, and allergic rhinitis (hay fever).
Asthma and eczema may be more severe in patients with allergy and are immune-mediated conditions. The most severe type of allergic reaction is known as anaphylaxis, which is potentially life threatening.
Please note that food allergies are different from food intolerances. Food intolerances are symptoms caused by specific foods but they are not due to an abnormal immune response to the food. Testing (blood tests and/or skin prick testing) can be required to determine whether a food allergy is present but sometimes it is clear cut from the history and testing is not required.
Urticaria (hives) and angioedema (swelling) are conditions of the immune system commonly confused with allergy and can present with somewhat similar symptoms. There can be environmental and drug triggers for these conditions, however the treatment of them is quite different to the treatment of allergy. Therefore, a proper diagnosis is important.
Autoimmunity
The normal immune system can tell the difference between “foreign” cells (such as from pathogens or cancer) and your own cells – “self”. In autoimmune diseases, the immune system mistakes proteins found in specific cells in part of your body. These cells might be in your joints or skin. The immune system sees them as foreign. It releases proteins called autoantibodies that attack healthy cells, mistaking them for foreign cells. This can establish an abnormal immune response with recruitment of many other types of immune cells, leading to tissue destruction.
Some autoimmune diseases target only one organ. For example, Type 1 diabetes damages the pancreas. Other diseases, such as SLE or “lupus”, can affect many different types of tissue throughout the whole body. Any tissue of the body can be affected in autoimmune disease, therefore many different symptoms are possible.
Autoimmune diseases are frequently treated with medications that suppress the immune system (immunosuppressants) or change the immune system to be less inflammatory (immunomodulators).
There are many autoimmune diseases which are not primarily treated by immunologists, but immunologists may be consulted if there is a lack of response to standard treatments. Autoimmune conditions can be treated by dermatologists, endocrinologists, neurologists, rheumatologists and ophthalmologists for instance without needing to see an immunologist in many cases. However, there are some conditions that are frequently primarily treated by an immunologist especially if they involve more than one system of the body (e.g. skin, nervous system, gut).
Immunodeficiency
Immunodeficiencies are serious, potentially life-threatening conditions that can lead to recurrent infections and, in some cases, cancers if untreated.
Primary immunodeficiencies are often due to genetic problems affecting the immune system. They are usually diagnosed in children, who develop very frequent and unusual infections. In adults, primary immunodeficiency may be milder and can therefore be more difficult to diagnose. It is usually detected due to frequent, severe or unusual infections as well.
Immunodeficiency may occur due to treatment for other medical conditions. This includes situations such as after chemotherapy. In these cases, it is called secondary immunodeficiency. It will also usually be diagnosed following multiple recurrent infections, which are often unusual, but it may be detected on screening tests in some cases.
Diagnosing immunodeficiencies is important. Other specific treatments may be required. These treatments include supplementary antibodies like intravenous immunoglobulin. They help prevent serious infections.
Contact us on 03 6221 9111 or reception@immuneclinic.com.au to learn how you can make an appointment with Dr Newman