COMMON INDOOR (year-round) RESPIRATORY ALLERGENS
d1. HOUSE DUST MITE:
Like a microscopic spider, at 0.3 mm, dust mites are only the size of a grain of salt. They don’t bite, but they are one of the most common sources of sensitization all over the world. They’ve a life cycle of 2-3 months and live in house dust, feeding from tiny bits of discarded skin. Shocking but true – up to 10% of the weight of a 2- year old pillow may be made up of dust mites and their droppings. They prefer a warm and humid environment, so you won’t find them in Antarctica or desert areas. But the mild damp Irish climate is particularly welcoming. You’ll
find them in all 4 provinces in pillows, carpets, mattresses and upholstered furniture (especially the TV couch). They just love damp. It’s their droppings/faeces that seem to be the biggest problem. Only as big as a grain of pollen, they are easy to inhale into the lungs.
Possible cross-reactions: Some of the same proteins are found in other mites – such as storage mites (which live in grains), and even other invertebrates and insects, including shrimps, snails, cockroaches and midges.
Symptoms: Due to their location, they are most commonly associated with perennial type asthma, rhinitis & conjunctivitis, and symptoms may be worst at night or early morning.
What to do: The best policy is avoidance. Studies show that reducing the numbers of mites, and mite allergens, will greatly reduce symptoms. This is best done through efficient cleaning (less dust = less mites), & lowering of air humidity & temperature. You can make it tougher on them by leaving bed covers off the bed in the morning. Put covers on couches – and wash these regularly at high temperatures. Remember that the water needs to be very hot (55 degrees C) to kill dust mites. There are effective dust-mite proof sheets and pillow-cases and mite repellent sprays are also helpful. Look at changing other floor coverings and furnishings that gather dust (such as curtains). Most of the dust you can see when light shines through a window is dead skin. Unhealthy skin sheds even more dust. If this is an issue, you might be able to reduce it by changing diet (foods and drinks) and by taking Omega-3 supplements and/or probiotic capsules. Symptoms will also be aggravated by other pollutants like cigarette smoke or fumes. You may also have to buy an air cleaner, but take one step at a time. The threshold that causes symptoms differs from person to person.
e1 CAT EPITHELIUM & DANDER:
Dander consists of dead cells from the animal’s skin. Ordinarily, this epithelium is replaced every 21 days, though it can be as fast as 3 days in unhealthy skin. The problem is not just the skin. Cats like to groom and coat their fur and skin with saliva, which also contains a prominent allergen. The allergens are found on upholstered furniture and clothing. And they get around - they can be transported into the classroom on clothing,. Children exposed to cat allergens are over 3 times more likely to show positive skin reactions to allergens than those who aren’t exposed. Equally, pre-natal or post-natal exposure to cats is believed to increase the risk of
developing sensitization to cats. Cat allergy is strongly associated with asthma. Cat allergy is more commonly involved in asthma than dog allergy.
Possible cross-reactions: Apart from related felines in the zoo, there is also possible cross-reactivity to horse, cattle, pig, rodents and other furry animals. There have also been cases of a cat/pork cross-reaction.
Symptoms: As for dust mites.
What to do: As allergen carried on clothes – even if there’s no cat in the home – may be enough to trigger symptoms, air filtering, and avoidance of cat exposure are the key methods to avoid problems. If allergic but the cat “must” stay, take proper precautions. Keep the pet out of the bedrooms. Always. Keep clothing that was in contact with the pet out of the bedroom. Always. Change pet bedding every month or two. Don’t allow pet hairs to gather anywhere, especially on clothing or couches.
e5 DOG DANDER:
The dander is made up of dandruff and hair, discarded dead skin cells. Animal dander consists of tiny particles that can remain airborne for hours. Animal dander is always present where there are pets, and often even where there were pets. They can also be carried on clothes, into work, schools or on public buses. In the home, the highest concentrations are generally found on carpets, mattresses, upholstered chairs and on the dog owners’ clothes. As a result, areas frequented by the dog will tend to have highest concentrations – living room, furniture, bedrooms.
Possible cross-reactions: Cats and other animals
Symptoms:Asthma, rhinitis and eye inflammation
What to do: As with cat allergy (above). if it is not feasible to find an alternative good home, then keep certain areas of the home as close to allergen-free as possible. Perhaps you could keep the dog outdoors during the day (in a kennel). Either way, keep dogs out of bedrooms. Vacuum carpets, mattresses and upholstery regularly. It may also help to encase covers and hot-wash linen and clothes.
m6 HOUSEHOLD MOULD:
Alternaria alternata is a very common mould species, found on plants, in soil, on foodstuffs and textiles. It is also often found on window frames with condensed water. It is generally considered an outdoor mould. It appears when weather becomes warm but can thrive at lower temperatures too, even in fridges. It is common in harvested fruits and vegetables (and causes spoiling of these during storage) as well as wheat, sorghum and barley, and has also been reported in oilseeds such as sunflower and rapeseed.It has even been detected (in Northern Ireland) in a pharmaceutical emollient cream.
Possible cross-reactions: Related moulds, yeast and fungi, including even candida (which gives rise to thrush)
Symptoms: Asthma, rhinitis. 17.6% of asthmatics in the UK & Ireland have antibodies to Alternaria alternata (5% in Southern Europe!)
What to do: Stop it from growing and stop it from releasing spores into the air when removing it. If you are in a damp area or house, use a dehumidifier at home.Use 5% ammonia solution (or commercial product) to remove mould from bathrooms and other contaminated surfaces. Replace carpets with wooden floors and wallpaper with paint. Repair any indoor leaks and water damage immediately. Minimize cutting grass in late summer when the mould spores are present in decaying vegetation.
Blatella Germanica is the most common variant, though Ireland also houses Asian and American variants. This small brown insect is one of evolution’s most resilient creatures and the most common varieties have evolved to live off human scraps. Cockroaches are also invariably found around the production of foods, including when harvested. The US FDA reported that the average chocolate bar contains 8 cockroach parts. The first cockroach allergy was reported in 1943, but the insect is steadily expanding into new areas. In houses, they prefer kitchens and may be found in amongst the plumbing, behind fixtures or in cracks. It thrives on warmth and damp – and food.
Possible cross-reactions: Related cockroaches and other shelled insects such as shrimps. Cockroaches can also infect food.
Symptoms: Asthma and other allergic conditions. Cockroaches seem to cause less sensitization in Northern Europe than Southern and more in Eastern Europe than Western. In Italy, about 20% of asthmatics are sensitized to cockroaches. In the Netherlands about 16%
of asthmatics (and 4% of non-asthmatics) had antibodies against cockroaches. In Norway, the figure dropped to7.5% while it was
over 34% of Russian adults and 63% of children.
What to do: Eliminate places for them to grow and food waste to feed them. Pest control companies can eradicate cockroaches if infestation is suspected. Seal cracks in floors and skirting boards. Control damp. Scrub floors with water and detergent to remove allergens. If infestation has occurred, bedding, curtains and clothing will also be contaminated and must be washed.
FOOD ALLERGENS (in infants and children)
Egg is one of the commonest causes of immediate food allergy in small children and infants, affecting about 2% of pre-school children. Egg white is generally a bigger allergic problem than egg yolk, though there is cross- reaction between the two. Egg white allergy is often involved in early development of eczema during infancy and respiratory problems in young children. Of those who have allergies, egg is commonly involved, in about 16% of cases overall, and in 44% of children under 5. This allergy often resolves itself with increased age and children may grow out of it.
Possible cross-reactions: Eggs from other related animals; egg in foodstuffs, though cooking may make the reaction either stronger or weaker (generally weaker). Egg is also common in soups, pastries, meringues, marshmallows, ice- cream, some beverages, some sausages or pates, omelettes, mayonnaise, pancakes, coatings for deep-fried foods. Traces of egg protein are also present in some vaccines.
Symptoms: Apart from eczema and asthma, it can also cause severe allergic reactions. Egg allergy can cause or aggravate atopic dermatitis, urticaria, angioedema, vomiting, diarrhoea, and rhinoconjunctivitis. When asthma is related to egg, there are usually also skin or digestive symptoms.
What to do: Avoid eating foods that contain eggs. If severe reactions have occurred learn about precautions (e.g. adrenaline pen)
Milk is a major causes of adverse reactions in infants and young children. It can give rise to stomach problems, eczema and upper respiratory tract problems. It can also cause severe allergic reactions. Milk allergy is not lactose intolerance. Lactose is a sugar found in milk. Most infants and small children worldwide can digest it but lose this ability as they grow. Northern Europeans have a gene that allows them to keep this ability into adulthood, so that most Irish people can drink milk even as adults (unless they suffer from milk intolerance, a separate condition). Only about 3-5% of “native” Irish lack this gene. As a result, lactose intolerance is rare here. Apart from obvious dairy foods like milk, cheese, butter and yoghurt, milk proteins are found in many foodstuffs, including processed meats (hams etc.), breads and pastry, processed foods, sauces, toppings (cream fillings).
Possible cross-reactions: there is considerable overlap between the proteins found in the milk of all mammals, though the ratios of the proteins differ. As a result there is considerable potential to cross-react. In other words,
an infant with cow’s milk allergy may develop a reaction to goat’s milk (but by contrast, the lactose in goat’s milk is better absorbed, which can help those who are mildly lactose intolerant). Human milk contains much less casein than whey (40:60 versus 80:20 in cow’s milk) so there is less cross-reaction. Heated or boiled cow’s milk has an even higher proportion of casein (as it is heat-stable). Modern pasteurized milk is probably more allergenic than the raw milk consumed by our ancestors.
Symptoms: Respiratory symptoms and asthma, gastrointestinal and skin conditions. 0.5 – 7.5% of infants show milk allergy.
What to do: Avoid milk and exercise great caution with alternative milk sources such as goat’s milk. Read labels and discuss with your doctor and learn emergency precautions in case of a severe reaction. Hydrolysation (partial breakdown) of milk proteins in infant formulae greatly reduces allergenicity , but some milk protein may remain. As with egg allergy, many children may outgrow the worst of it. Where possible, breast-feed children to reduce the risk of milk allergy. In older age-groups, symptoms due to milk may be linked to appearance of IgG antibodies against dairy proteins.