| Also known as allergists, immunologists are doctors who diagnose, treat, and work to prevent immune system disorders. Immunology doctors (immunologists) specialise in understanding and treating issues related to the immune system. If your immune system is not working as it should, you may see an immunologist. Some immunology doctors specialise in treating allergies and are known as allergists. What is the immune system? The immune system is the body’s defence against infections and other diseases. It is a complex network of cells, tissues, molecules, and organs that work together to keep you healthy. Your immune system can tell the difference between your own cells and foreign invaders such as bacteria and viruses. When it detects foreign invaders, it attacks. It is constantly at work, even when you don’t realise it, protecting you from the countless germs you encounter daily. How can the immune system go wrong? If your immune system isn’t working like it should be, it can result in: Immunodeficiency: when the immune system is too weak to defend the body. Autoimmunity: When the immune system mistakenly attacks the body’s own cells. Mast cell activation disorders: When the immune system is too sensitive and overreacts. These immune system problems are called ‘immune dysfunction’. Whilst there is currently no evidence directly linking immune dysfunction and EDS/HSD, it is recognised that patients with EDS/HSD experience immune dysfunction more frequently than the general population [1]. Symptoms you may see an immunologist for. – If you have frequent, severe or unusual infections. – If you have allergies or allergic-type symptoms that are hard to control. – If you have symptoms of autoimmune disease (although these are usually treated by doctors who specialise in the organ/body system affected; for example, rheumatologists treat autoimmune connective tissue disorders). – If you have asthma that isn’t well controlled with regular treatments. – If you have an inherited (genetic) immune disorder (primary immune deficiencies). What do immunologists do? Immunologists will do testing, such as blood and urine tests, and analyse these results alongside your symptoms to diagnose problems with your immune system. Once they know what is causing your symptoms, they may recommend treatments to help your immune system work more effectively and alleviate your symptoms. What are Mast Cells? Mast cells are immune cells that play a crucial role in allergic reactions. When they are stimulated by an invading allergen, they release molecules to protect you from the invader. One of the molecules they release is histamine. Histamine produces the hallmark signs of an allergic reaction, such as redness, swelling, and itching. Another molecule mast cells release is leukotrienes. Leukotrienes contribute to asthma symptoms. Mast cell disorders occur when mast cells are too sensitive and release their molecules too easily. Many mast cell disorders exist, such as asthma and allergies. Mast cell activation syndrome Mast Cell Activation Syndrome(MCAS) occurs when your mast cells are too sensitive and overreact to many triggers, including strong emotions, heat/cold, exercise, and allergens (like foods and medicines). In allergic reactions, mast cells are triggered by a protein called an antibody. In mast cell activation syndrome, mast cells can be triggered even when this protein is not present, which is why allergy tests are often normal in MCAS patients. MCAS symptoms [3] MCAS can cause many different symptoms because the chemicals released by mast cells affect multiple body systems. Some of the symptoms you may experience are listed below. You may experience some of these or lots of them. There may also be other symptoms caused by mast cell activation which are not listed. Skin – hives, swelling, itching, warmth, redness, flushing Respiratory (breathing) – coughing, wheezing, shortness of breath, chest pain or tightness, throat tightness, trouble swallowing, hoarse voice, hay fever-like symptoms. Gastrointestinal (digestive system) – feeling or being sick, stomach pain/cramps, diarrhoea. Cardiovascular (heart and blood vessels) – dizziness/lightheadedness, pale/blue skin, weak pulse, and fainting. Neurological (brain and nervous system) – anxiety, headache, feeling of impending doom. MCAS treatments There are several treatment options for managing MCAS symptoms. Your doctor will consider your symptoms, test results and past medical history when deciding on the best treatment for you. Some common options include: Antihistamines – known as H1 and H2 blockers Mast cell stabilisers – such as sodium cromoglicate and Ketotifen. Leukotriene receptor antagonists– such as montelukast In some countries, especially America, a medication called Omalizumab (Xolair) is used to treat MCAS. However, in the UK, this medication is only available for preventing ‘severe persistent allergic asthma’ and as an ‘add-on therapy’ for chronic spontaneous urticaria (persistent hives with no apparent trigger) when antihistamines are not effective. This is due to medication licencing rules in the UK [3]. MCAS and EDS/HSD MCAS is seen in a subpopulation of EDS/HSD patients, and several researchers have suggested links between MCAS and EDS [4]. What to expect at an immunology appointment NHS Immunology departments vary in what they cover and what referrals they will accept across the country – you can usually find this information out on the hospital, NHS board or Trust website. Your GP (or whoever is referring you) should be able to check the most appropriate place for you to be referred to, based on your symptoms. On your first visit to immunology, the specialist doctor will ask you lots of details on your symptoms, what trigger them and how they gave impacted on your day-to-day life. They might need to examine you too. It might be helpful if you have recurring and episodic symptoms (things that ‘come and go’) to keep what is known as a symptom diary. Within this, you keep track of what symptoms you have, how severe they are, when this happens and for how long. This can be useful to refer to during the consultation, or to give to your healthcare professional. If you have rashes/hives or something similar that are not there all the time, it might be helpful for your healthcare professional to take pictures and/or videos. This initial consultation can take some time, especially as these conditions are usually complex, and you might have other related health problems. They might want to do some tests – like blood tests or an ECG – on the day, or you might be asked to come back for some more complex testing. Below is a good resource on what some of the common immunology blood tests mean – https://mft.nhs.uk/immunology-investigations-undertaken-in-the-department-and-annual-review-procedure/. Some people might get specific allergy testing (i.e. a skin prick test). This is when a potential allergen (food, pollen, dust mites) is placed on your skin, followed by a ‘prick’ into your skin. There is another form of allergy test where the potential allergen is injected into the skin (this is an intra-dermal test). Again, different health trusts/boards will carry these out differently – a good summary can be found here: https://mft.nhs.uk/allergy-investigations-and-procedures/#1. |