Could you be allergic to your house? Katie couldn't work out what caused chronic attacks that left her gasping for breath Mould spores can cause nasal stuffiness, itchy eyes, coughing, eczema 4% of the population reacts to the spores, which can cause lung damage Mould thrives in the damp; if your house is tepid, mould will grow there Weekly attacks: Katie Fant experienced severe allergic reactions to mould As the autumn damp sets in, the temptation is to stay inside and turn up the radiator. But if there's not enough ventilation, you could be creating the perfect environment for mould to grow. Mould can trigger breathing problems and may even, in rare cases, be life-threatening - as Katie Fant discovered. Last November, the 17-year-old was at school when she suddenly started struggling to breathe. 'I was sitting in class and my throat began to close up and then my tongue started to swell - I ran to the first aid room,' recalls Katie who lives in Bexley, Kent, with her mother Roberta, 43, a teacher, stepfather Gary, 40, a cab driver, and younger siblings, Rachel and Daniel. Within minutes, large itchy red hives - about an inch in diameter - had started to appear on her arms and chest. Luckily, a paramedic arrived within ten minutes and gave her an adrenaline injection; this calmed down her symptoms, but she was still rushed to hospital in an ambulance, where she was also given steroids. Katie had experienced an extreme anaphylactic reaction - a severe allergic reaction where the body's immune system goes into overdrive, releasing large amounts of histamine, a chemical that causes tissue to swell. This can lead to breathing problems and a drop in blood pressure. It can be fatal. After eight hours in hospital, Katie was well enough to go home. But the mystery was what caused the attack. Although she suffers from hay fever and oral allergy syndrome - where certain foods, in her case, fresh fruit, cause her mouth to tingle and lips to swell temporarily - there was nothing to suggest these were the problem. 'I hadn't eaten anything out of the ordinary,' recalls Katie. Her GP referred her to an allergy specialist, but there was a three-month wait. In the meantime she had at least one anaphylactic reaction every week, always at school. Scarily the symptoms developed more rapidly each time - I took antihistamines every day to prevent an attack and carried two EpiPens of adrenaline at all times, which I used. Although my symptoms would quickly die down, I was told to go to A&E each time in case there were problems when the adrenaline wore off. It was terrifying,' says Katie. She was also told to rest for at least a week after each attack. My attendance levels dropped to below 60 per cent. I was in my first year of A-levels and every class I missed set me back. It began to affect my grades. Mould allergy: The fungus, like the black variety found on window frames, thrives in damp, moist conditions The school helped and teachers came to my home when I was off sick, but without knowing the trigger, there was little they could do. She was advised to restrict her diet, so ate the same thing every day - mainly oat cereal and bread - but it made no difference. I became very anxious and quite depressed because home was about the only place I felt safe and I missed out on a lot of things. I don't think my friends believed it when I said I was allergic to school.' When Katie eventually saw an allergy specialist at Guy's Hospital, London, in January, tests revealed she had allergies to pollen, peanuts and sesame, but her strongest allergy was to mould - particularly cladosporium herbarum, a mould found on window frames, fridges and poorly ventilated buildings. The penny dropped. As Katie explains: 'My school building was old and quite damp and one class was in a temporary hut - it had condensation on the window sills and black mould on a wall. This was where I had the majority of attacks. After Mum knew about my mould allergy she opened all our windows regularly and bought a dehumidifier for my room. But I never had an attack at home, so obviously it was something at school setting me off. Mould is a type of fungus - thousands of types are released at different times of the year, though autumn is the peak time for the release of the spores (the microscopic particles that allow it to spread). The spores can irritate skin, nasal and bronchial membranes, causing symptoms such as nasal stuffiness, itchy eyes, coughing, wheezing, and eczema. Up to 4 per cent of the population is thought to react to mould spores - with as many as one in ten people with allergies such as hay fever and eczema affected. Mould spores can also be dangerous for some asthmatics - around two-thirds of the more serious life-threatening asthma attacks are believed to be triggered by moulds, although anaphylactic reactions such as those Katie had (causing changes in blood pressure, for instance) are fortunately rare. Dr George Du Toit, consultant paediatric allergy specialist at St Thomas's Hospital, London, and the private Portland Hospital, says late autumn is the peak time for mould allergies due to the wet conditions and fallen leaves, and people spending more time indoors with windows shut, which leads to condensation forming. 'I don't think my friends believed it when I said I was allergic to school.' Mould thrives in damp, moist, tepid conditions, indoors and out. The black mould on window frames is an obvious type, but you'll also find mould in steamy kitchens and bathrooms, and barns where mouldy hay is stored, or musty sheds or garages,' says Dr Du Toit. If your house has damp, it is the ideal environment for mould to thrive. Patients are often puzzled about what is causing their allergic symptoms, as they don't tend to think of mould being a trigger.' Lyndsey McManus, deputy chief executive of Allergy UK, stresses that mould can grow in centrally heated, double-glazed homes as well as old damp houses and overcrowded flats: 'If the house isn't well ventilated, mould will flourish.' Certain mould species can also cause serious lung infections and damage. Aspergillus, for instance, colonises vegetable matter (especially wet or rotting) and can be found on farms where produce is stored, or in old buildings. The spores can trigger an allergic reaction (usually asthma) and, in rare cases, it can damage tissue in the lungs and affect breathing. Aspergillus can be a problem for people with serious pre-existing lung diseases, says consultant chest physician Dr Keith Prowse, who advises the British Lung Foundation. 'There's another condition called farmer's lung, where lungs are colonised by spores from mouldy hay. It can cause scarring of the lung, make patients breathless and even prove fatal,' he says. Irritation: Spores can cause symptoms such as nasal stuffiness, itchy eyes, coughing, wheezing, and eczema Mould may also be linked to Parkinson's disease. A new U.S. study found a compound given off by mould reduced levels of the brain chemical dopamine, a process which causes Parkinson's symptoms, although more research is needed. As well as eliminating existing mould with anti-mould products, experts advise opening windows every day to release moist air, using dehumidifiers and fitting ventilation fans in kitchens and bathrooms. Avoid drying washing indoors, particularly on radiators, and keep pot plants to a minimum (topsoil can harbour mould). Dr Nicholas Osborne, a toxicologist, epidemiologist and senior research fellow at the University of Exeter's Medical School at the European Centre for Environmental Health, says: 'Mould thrives in any building where there's insufficient ventilation and condensation happens. Climate change experts say the weather in the UK will get wetter and warmer, and mould thrives in wet conditions and warm temperatures, so mould-related health problems will probably increase, too. For mould-related allergies, prevention and treatment is with antihistamines, with oral steroids sometimes used to treat flare-ups. But in severe cases Dr Du Toit says the patient is exposed to an allergen in hospital conditions in progressively larger doses, so that the immune system eventually becomes desensitised and does not react. Katie Fant ended up changing schools to combat her attacks. Since doing this in September she's had just two attacks. 'I still worry about attacks though - I want to go to university to study law, but I'm nervous about moving away from home and having to live in an unknown environment. I want people to know just how serious mould allergies can be. allergyuk.org