allergies

Posted on Multiple Sclerosis

Food allergies and multiple sclerosis: study reveals a new link

Food allergies and multiple sclerosis: study reveals a new link

Food allergies and multiple sclerosis: study reveals a new link

Like many other medical conditions, the mechanism of multiple sclerosis remains an enigma–a puzzle composed of complex genetic and environmental factors. A key piece to this puzzle is the immune system, which is also responsible for regulating many other physiological (and pathological) phenomena–including allergies. Although previous studies investigating the association between MS and allergies have yielded mixed results, a research team at Brigham and Women’s Hospital sought to uncover the putative link in a new way. Investigating the correlation between allergy and inflammatory disease activity, the team found new evidence connecting food allergies and relapses of multiple sclerosis. The results are published in the Journal of Neurology, Neurosurgery & Psychiatry.

“Some multiple sclerosis patients with significant allergies would complain of frequent relapses associated with their allergic episodes,” said Tanuja Chitnis, MD, senior author and a neurologist at the Partners MS Center at the Brigham. “We felt that the most likely mechanism associated with allergy and its influence on MS would be related to inflammatory activity.”

Accordingly, Chitnis and colleagues set out to investigate the association between inflammatory disease activity and allergy history in a subset of patients enrolled in a large study known as the Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB). A total of 1,349 study participants completed a self-administered questionnaire outlining food, environmental and/or drug allergies. Disease activity was assessed through evaluating the cumulative number of attacks over disease course, and new gadolinium (Gad)-enhancing lesions, as detected by MRI.

Interestingly, only participants in the food allergy group demonstrated a significantly higher rate of cumulative attacks and increased likelihood of new Gad-lesions compared to participants with no reported food allergies. This effect remained significant even when adjusted for potential confounders such as sex, age at symptom onset, and disease category. No significant effects were observed for the environmental and drug allergy groups after adjusted analyses.

This association between food allergy and MS disease activity highlights an important role for a potential player in immunity and inflammation–the gut. “It is interesting that this association was only found with food allergies and not other types of allergies, which might have been expected had this solely been an immune deviation issue,” said Chitnis. “The presence of food allergies and mechanisms related to food allergies may increase relapse rate and inflammatory activity in MS patients. There may be a common mechanism here, or other mechanisms which may induce MS relapses in a predisposed host.”

Currently, Chitnis and colleagues are working to further uncover these mechanisms of immune dysregulation in allergy and delineate how such dysregulation impacts MS inflammatory activity. Given the correlative nature of this study, the researchers are careful to highlight the limited clinical actionability of their findings. However, Chitnis is optimistic about the potential translational significance of the work and highlights the importance of addressing food allergies in MS patient care.

“There has long been a hypothesis of the gut being related to the immune system, and this really points to a stronger association than previously understood,” Chitnis said. “This research opens up a new way of thinking about the immune mechanisms in MS.”

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Nearly a quarter of us may be allergic to our own homes

Allergic to our own homes

Allergic to our own homes

At least 12 million Britons now suffer from allergies caused by dust mites, The Independent has today reported. The newspaper says that a report by the charity Allergy UK has revealed an epidemic of “home fever”, a range of symptoms caused by dust mites and other triggers around the home.

The report has been published as part of Indoor Allergy Week, which is intended to raise awareness of the kind of steps that can be taken to remove allergy triggers, or ‘allergens’, from the home. A survey in the report suggests that, currently, around two-thirds of people with allergies experience symptoms such as sneezing and itchy eyes caused by allergens including dust mites, chemicals, pets and mould.

This new report raises lots of questions, such as whether its small survey of symptoms in 1,600 allergy sufferers is actually strong enough evidence to suggest that there is an epidemic sweeping the nation.

Also, the report’s suggestions to change your mattress and use an air filter are likely to raise a few eyebrows since the awareness week is being run in conjunction with a mattress company and an air filter manufacturer.

 

What is “home fever”?

“Home fever” is a term used by Allergy UK to describe out-of-season hay fever symptoms. The most common of these are runny nose and sneezing, symptoms which the charity reports have risen greatly in recent years. Unlike regular hay fever, which is usually triggered by high pollen levels that vary seasonally, “home fever”, Allergy UK suggests, is triggered by allergens such as dust mites, moulds, cleaning products and pets that are present in the home or office. These can cause symptoms throughout all seasons.

 

Who compiled the report?

The news is based on a report by Allergy UK that surveyed more than 1,600 allergy sufferers about indoor allergies. The report was released ahead of Allergy UK’s Indoor Allergy Week, launched today, which aims to raise awareness about indoor allergies caused by house dust mites, moulds and pets.

As mentioned above, the awareness-raising week and report are supported by a mattress company and an air purifier manufacturer. It is not clear what role these companies had in the survey, which featured recommendations to prevent “home fever” by replacing your mattress and using an air purifier. This affiliation may be something to take into account when considering the report’s recommendations.

Allergy UK is a national charity supporting people with allergies, food intolerance and chemical sensitivity.

 

What did the report say?

The survey asked allergy sufferers what triggered their symptoms, offering the possible options of house dust mites, cleaning products, mould or pets. Participants could choose more than one option. The most popular answer was house dust mites at 57.6%, followed by pets (45.2%), cleaning products (31.2%) and mould (30.9%).

The report says these figures have risen since the last survey was published in February 2010. The Allergy UK report does not give any detail on the characteristics of the people surveyed or how many people answered each question. It also does not include any statistical analysis to say whether the differences observed between years are real or the result of random variation that occurs when different groups of people are surveyed. We must be very cautious in taking these figures at face value without more information about how the survey was carried out.

The most commonly reported symptoms of indoor allergy or “home fever” were runny nose (67.8%), sneezing (66.9%) and itchy eyes (62.1%).

Other findings include:

58.9% of indoor allergy sufferers found their symptoms were worse in the bedroom. The authors suggest that this was due to dust mites in the bed, quoting figures that “the average bed harbours 2 million dust mites and the average pillow doubles in weight over a period of six months due to dust mite faeces”.

16% of allergy sufferers said they wash bed linen every three weeks or less often, and 58% of those surveyed said they are washing at 30 or 40 degrees. This is two weeks longer than Allergy UK recommends and at a temperature that they say does not kill any dust mites present.

13% of allergy sufferers had had their current mattress for 11 years or more, and 3% kept theirs for 20 years or longer.

The authors suggest people “too often confuse allergy symptoms with a common cold or flu and, therefore, don’t treat the root cause of the problem”. Allergy UK believes the root cause is allergens such as dust mites, which trigger these allergic reactions and symptoms.

 

How common are household allergies?

Allergy UK estimates that at least 12 million people are allergic to their own home and so could be classed as household allergy sufferers. NHS Choices reports that indoor allergies are very common and that 10-20% of the population has an indoor allergy. The top estimate of 20% would be broadly in line with the figure suggested by Allergy UK, although it is not apparent how the charity has reached this estimate.

Most sufferers first develop indoor allergies in childhood, with 80% of cases developing before the age of 20. Men and women are equally affected by indoor allergies.

 

What causes household allergies?

The main cause of indoor allergies or “home fever” are house dust mites. Dust mites are microscopic creatures that survive well in warm damp conditions such as the average UK home. Beds provide the ideal environment for dust mites as they can feed on the skin cells we shed, obtain warmth from our bodies and gather water from our sweat and exhaled breath. They are also commonly found in carpets, upholstered furniture, fabrics and furry toys. While they are completely harmless to most people, in some they can trigger an allergic reaction. The allergen that triggers most allergic reactions is the mite droppings. These can collect in pillows, mattresses, duvets, upholstery and carpets.

Other common causes of indoor allergies include allergens from animals and from mould spores.

 

What can I do to ease my allergies?

Allergy UK recommends many ways to manage symptoms and reduce the amount of indoor allergens in the home.

Buy products that have been tested to ensure they prevent the escape of the house dust mite allergen.

Use allergen-proof barrier covers on all mattresses, duvets and pillows.

Dust regularly but use a damp duster first, then a dry cloth. Otherwise, you are just moving the dust around.

Wash all bedding that is not encased in a barrier cover (for example sheets and blankets) every week. Washing at 60 degrees or above will help eliminate house dust mites. The allergens produced by house dust mites dissolve in water so, while washing at lower temperatures will wash the allergens away temporarily, the mites will survive and produce more allergen after a while.

If possible, remove all carpeting in the bedroom and vacuum all surfaces of upholstered furniture at least twice a week.

Change your mattress every 8-10 years and replace pillows every year.

Use a high-temperature steam cleaner to rid carpets of dust mites.

Use light, washable cotton curtains, and wash them frequently. Reduce unnecessary soft furnishings.

Washable stuffed toys should be washed as frequently and at the same temperature as bedding. Alternatively, if the toy cannot be washed at 60 degrees place it in a plastic bag in the freezer for at least 12 hours once a month and then wash at the recommended temperature.

Reduce humidity by increasing ventilation. Use trickle-vents in double-glazing or open windows. Use extractor fans in bathrooms and kitchens.

If necessary, use a dehumidifier to keep indoor humidity between 30 and 50%, plus an air purifier to trap large airborne allergens such as pollen, house dust mite debris and mould spores.

These are just some of the recommendations given. To read the recommendations in full visit the Allergy UK website.

One point to note is that in the Allergy UK publication participants reported on various symptoms, most commonly runny nose, sneezing and itchy eyes (typical symptoms of allergy), but also a wider range of symptoms such as wheezing, disturbed sleep and poor concentration. The full range of symptoms offered is not specific to allergy, and could cover many things, including symptoms of the common cold and flu.

Additionally, participants appear to have self-reported what they believe triggers their symptoms. Therefore, taking these things into account, people with respiratory symptoms, irritable skin, poor concentration or difficulty sleeping should not necessarily assume that these symptoms are due to household allergies. If symptoms persist it may be advisable to see your GP.

Do these preventative measures work?

A recent high-quality systematic review looked at the evidence on whether controlling exposure to house dust mites improved asthma symptoms in people who were sensitive to house dust mites. Chemical and physical preventative measures were examined, including mattress covers, vacuum-cleaning, heating, ventilation, freezing, washing and air filtration. Measures of asthma included subjective wellbeing, medication use and various established measures of airway function.

The review, which included 3,121 patients from 55 studies, concluded that these measures had no effect on asthma symptoms (i.e. they were no more effective than doing nothing) and that such measures could not be recommended.

This high-quality review focused on symptoms of asthma caused by dust mites and not the more general symptoms of a runny nose and sneezing as described for “home fever”. It also does not specifically address each of the Allergy UK recommendations. However, it raises an important question. If controlling exposure to dust mites in these ways fails to improve asthma allergic reactions caused by house dust mites, would they be effective in preventing “home fever” also caused by dust mites?

Currently it is not known whether these preventative measures are effective in preventing “home fever”. This should be kept in mind before making potentially costly changes to your bedroom or house to reduce dust mite allergens.

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“The Hygiene Hypothesis” Are we too clean for our own good?

the hygiene hypothesis

the hygiene hypothesis

Are we too clean for our own good?

Many people think our obsession with cleanliness is to blame for the rise in allergies such as hay fever, eczema and asthma.

The idea is that modern hygiene standards have reduced our exposure to good and bad germs, which can help strengthen the immune system, the body’s mechanism for keeping us healthy.

Over the past 20 years there has been a rise in allergies, and no-one really knows why. Around one in four people in the UK suffers from an allergy at some point in their lifetime and numbers are increasing every year.

Research suggests that exposure to germs is only one possible reason for this and diet, lack of exercise, our environment, use of antibiotics and a family history of allergies may play a bigger role.

But what is increasingly clear from the evidence is that hygiene standards should not be relaxed to try to reduce the risk of developing an allergy.

Are we being too clean?

No. It is very important that we maintain good standards of personal and home hygiene.

Good hygiene is about avoiding infection and preventing the spread of infection to others. Good hygiene isn’t about being dirt-free and doesn’t require being obsessively clean. Good hygiene is about preventing the spread of germs at times and in places and situations where it really matters, such as when preparing food, after using the toilet, after sneezing and when someone’s ill with an infection.

Find out how to prevent germs from spreading.

 

Where did this idea of being ‘too clean’ originate?

The idea is based on “the hygiene hypothesis”, first proposed in a 1989 study by Prof David Strachan, which suggests that a lack of childhood exposure to harmful germs and fewer childhood infections are to blame for the rise in allergies.

Although it is catchy, the phrase “hygiene hypothesis” is somewhat misleading and it has been wrongly used in the media to suggest that modern hygiene standards are bad for our health.

It is important that we do not relax our personal and home hygiene standards. Exposure to germs is only one of several reasons that could explain the rise in allergies and may not be the most important one.

Check an interactive guide on hygiene hypothesis from the International Scientific Forum on Home Hygiene.

Can homes really be ‘too clean’?

No amount of cleaning can rid the home of germs. As fast as they are removed by cleaning, new germs return via humans and pets, contaminated food, the outside air etc. The idea that we now live in sterile homes is totally wrong. It’s impossible to sterilise our homes.

 

Why is hygiene important?

Good hygiene is critical in stopping the spread of disease-causing germs, such as colds and flu, tummy bugs like campylobacter, salmonella and E. coli O157, in the home and beyond, on food, from our pets and between people. Particular care should be taken to protect at-risk groups such as babies, whose immune systems have not fully developed, and people with a weakened immune system because of illness or medication.

 

Doesn’t exposure to germs strengthen our immune system?

It is thought that exposure to both good and bad germs in the first few years of life helps to develop the immune system – an idea distinct to the hygiene hypothesis. This helps the body to learn how to fight infection and to tell the difference between harmful and harmless substances.

Throughout life, it is also important that our bodies have the right balance of some exposure to both good and bad germs (present in our everyday environment), particularly in our gut and on our skin, to ensure that the immune system is trained to deal with different kinds of substances. Changes in this balance can cause the immune system to react unpredictably and it may find it difficult to tell when it is being attacked.

Maintaining this balance means not being afraid of getting outside and getting dirty sometimes. However, you should take every precaution to reduce your exposure to harmful germs by ensuring good personal and home hygiene, particularly if you are in an at-risk group.

Exposure to germs such as E.coli, norovirus and the measles virus can be very dangerous and can lead to life-threatening illnesses. These types of infection can cause permanent damage to your body and immune system so it cannot fight infection as well when it is attacked again.

People who maintain a healthy lifestyle tend to have a stronger immune system. Lifestyle factors that can weaken the immune system include drinking too much alcohol, poor diet and stress.

But can’t you develop immunity to germs like salmonella, E. coli, flu and so on?

To a certain extent, yes. Coming into contact with a specific harmful germ such as salmonella or measles will cause the body to respond and make antibodies, which neutralise the germ and protect against that particular germ. But deliberately exposing yourself to such germs is risky because you may become very seriously ill before your body can respond and fight the infection – and if you survive you will only have developed immunity against that particular germ.

This is why we developed vaccines so that we can be exposed to small safe doses of germs such as the flu, the measles virus and so on in a carefully controlled way that gives us protection without making us ill.

 

So what else could explain the rise in allergies?

Allergies have risen sharply over the past two decades and we’re not entirely sure why. Changes to the types of germs we come into contact with is only one factor among many that may explain this rise. Other factors include changes in diet and eating allergy-causing foods, where we live, a family history of allergy and how physically active we are.

One theory suggests that we have lost touch with a bunch of good germs, known as “old friends”, that humans evolved alongside back in the Stone Age, when our immune system was still developing. How this may have come about isn’t entirely clear, but measures to protect us from harmful germs – such as public sanitation – may have inadvertently cut us off from these good germs, which live in similar environments.

 

Who are these old friends?

Scientists aren’t entirely sure, but research suggests they include some of the good germs found on the skin, gut and throat area as well as in our outdoor environment, especially the countryside, which may explain why children on farms have less asthma. These old friends are not thought to include harmful germs that spread infectious diseases such as colds, flu, measles, salmonellosis, norovirus etc.

For more information on the old friends theory, read  The Hygiene Hypothesis and its implications for home hygiene, lifestyle and public health (International Scientific Forum on Home Hygiene).

 

Should we therefore be more relaxed about hygiene?

Even good old countryside dirt can contain harmful germs. So, relaxing hygiene would only expose us to “new enemies”, like E. coli O104, not our old friends. That would raise the risk of infectious disease and take us back to the days when lives were short and one in four children died before the age of five.

 

So are you less likely to develop allergies if you live on a farm?

There is some evidence that children who grow up on farms develop fewer allergies. The theory is that farms (particularly farm animals) increase exposure to different types of good and bad germs, which stimulate the immune system and reduce the risk that someone will develop an allergy.

Are the chemicals in cleaning products linked to the rise in allergies?

No, there is currently no evidence that links the use of household cleaning products, or their ingredients, such as antibacterial agents, to the rise in allergies, such as hay fever and asthma.

 

Is personal hygiene a likely factor in the rise in allergies?

Bathing and showering does remove germs from our skin but there is no evidence linking frequency of washing, showering or bathing to an increased risk of allergies.

 

Are antibiotics to blame for the rise in allergies?

There is some evidence linking the use of antibiotics with the rise in allergies. It is thought that antibiotics may reduce the amount of germs on our skin and in our gut. This upsets the body’s normal balance and the immune system finds it difficult to tell the difference between harmless and harmful germs.

 

Are vaccines to blame for the rise in allergies?

Vaccines are not thought to be associated with rising allergy levels. Vaccination has saved more lives and prevented more serious diseases than any advance in recent medical history.

Vaccines work by stimulating our immune system to produce antibodies (substances produced by the body to fight disease) without actually infecting us with the disease. As with all new medicines, all vaccines are extensively tested for safety before they’re made routinely available to the general public. Find out more about vaccinations.

 

Are changes in diet to blame for the rise in allergies?

There is some evidence that changes to childhood diets may be responsible for an increase in allergies.

It is thought that introducing foods that can cause an allergy (allergens) such as peanuts, milk and egg during weaning and alongside continued breastfeeding, can reduce the number of children developing allergic disease in later childhood. However, this is only a theory and there are currently a number of studies ongoing around the world that aim to answer this very important question.

Until we know the answer, mothers should continue to follow the current national advice, which is to exclusively breastfeed your baby for around the first six months of their life and not to give them allergenic foods before six months of age, such as peanuts, nuts, seeds, egg, fish, shellfish, milk, soya, wheat (and other cereals that contain gluten such as rye, barley and oats). Find out more about breastfeeding and weaning.

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Allergic rhinitis – how to prevent allergic rhinitis?

Allergic rhinitis - a guide

Allergic rhinitis – a guide

The best way to prevent allergic rhinitis is to avoid the allergen that causes it.

But this isn’t always easy. Allergens, such as dust mites, aren’t always easy to spot and can breed in even the cleanest house.

It can also be difficult to avoid coming into contact with pets, particularly if they belong to friends and family.

Below is some advice to help you avoid the most common allergens.

House dust mites

Dust mites are one of the biggest causes of allergies. They’re microscopic insects that breed in household dust.

To help limit the number of mites in your house, you should:

consider buying an air-permeable occlusive mattress and bedding covers – this type of bedding acts as a barrier to dust mites and their droppings

choose wood or hard vinyl floor coverings instead of carpet

fit roller blinds that can be easily wiped clean

regularly clean cushions, soft toys, curtains and upholstered furniture, either by washing or vacuuming them

use synthetic pillows and acrylic duvets instead of woollen blankets or feather bedding

use a vacuum cleaner fitted with a high efficiency particulate air (HEPA) filter – it can remove more dust than ordinary vacuum cleaners

use a clean damp cloth to wipe surfaces – dry dusting can spread allergens further

Concentrate your efforts on controlling dust mites in the areas of your home where you spend most time, such as the bedroom and living room.

Pets

It isn’t pet fur that causes an allergic reaction, but exposure to flakes of their dead skin, saliva and dried urine.

If you can’t permanently remove a pet from the house, you may find the following tips useful:

keep pets outside as much as possible or limit them to one room, preferably one without carpet

don’t allow pets in bedrooms

wash pets at least once a fortnight

groom dogs regularly outside

regularly wash bedding and soft furnishings your pet has been on

If you’re visiting a friend or relative with a pet, ask them not to dust or vacuum on the day you’re visiting because it will disturb allergens into the air.

 

Pollen

Different plants and trees pollinate at different times of the year, so when you get allergic rhinitis will depend on what sort of pollen(s) you’re allergic to.

Most people are affected during the spring and summer months because this is when most trees and plants pollinate.

To avoid exposure to pollen, you may find the following tips useful:

check weather reports for the pollen count and stay indoors when it’s high

avoid line-drying clothes and bedding when the pollen count is high

wear wraparound sunglasses to protect your eyes from pollen

keep doors and windows shut during mid-morning and early evening, when there’s most pollen in the air

shower, wash your hair and change your clothes after being outside

avoid grassy areas, such as parks and fields, when possible

if you have a lawn, consider asking someone else to cut the grass for you

Mould spores

Moulds can grow on any decaying matter, both in and outside the house. The moulds themselves aren’t allergens, but the spores they release are.

Spores are released when there’s a sudden rise in temperature in a moist environment, such as when central heating is turned on in a damp house or wet clothes are dried next to a fireplace.

To help prevent mould spores, you should:

keep your home dry and well ventilated

when showering or cooking, open windows but keep internal doors closed to prevent damp air spreading through the house, and use extractor fans

avoid drying clothes indoors, storing clothes in damp cupboards and packing clothes too tightly in wardrobes

deal with any damp and condensation in your home

Read more about how damp and mould can affect your health and how to get rid of damp and mould.

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Allergic rhinitis – What are the signs and symptoms of Allergic rhinitis? Part One

Allergic rhinitis - a guide

Allergic rhinitis – a guide

Allergic rhinitis is inflammation of the inside of the nose caused by an allergen, such as pollen, dust, mould, or flakes of skin from certain animals.

It’s a very common condition, estimated to affect around one in every five people in the UK.

Signs and symptoms

Allergic rhinitis typically causes cold-like symptoms, such as sneezing, itchiness and a blocked or runny nose. These symptoms usually start soon after being exposed to an allergen.

Some people only get allergic rhinitis for a few months at a time because they’re sensitive to seasonal allergens, such as tree or grass pollen. Other people get allergic rhinitis all year round.

Most people with allergic rhinitis have mild symptoms that can be easily and effectively treated. But for some symptoms can be severe and persistent, causing sleep problems and interfering with everyday life.

The symptoms of allergic rhinitis occasionally improve with time, but this can take many years and it’s unlikely that the condition will disappear completely.

When to see your GP

Visit your GP if the symptoms of allergic rhinitis are disrupting your sleep, preventing you carrying out everyday activities, or adversely affecting your performance at work or school.

A diagnosis of allergic rhinitis will usually be based on your symptoms and any possible triggers you may have noticed. If the cause of your condition is uncertain, you may be referred for allergy testing.

Read more about diagnosing allergic rhinitis.

What causes allergic rhinitis?

Allergic rhinitis is caused by the immune system reacting to an allergen as if it were harmful.

This results in cells releasing a number of chemicals that cause the inside layer of your nose (the mucous membrane) to become swollen and excessive levels of mucus to be produced.

Common allergens that cause allergic rhinitis include pollen – this type of allergic rhinitis is known as hay fever – as well as mould spores, house dust mites, and flakes of skin or droplets of urine or saliva from certain animals.

Read more about the causes of allergic rhinitis.

Treating and preventing allergic rhinitis

It’s difficult to completely avoid potential allergens, but you can take steps to reduce exposure to a particular allergen you know or suspect is triggering your allergic rhinitis. This will help improve your symptoms.

If your condition is mild, you can also help reduce the symptoms by taking over-the-counter medications, such as non-sedating antihistamines, and by regularly rinsing your nasal passages with a salt water solution to keep your nose free of irritants.

See your GP for advice if you’ve tried taking these steps and they haven’t helped. They may prescribe a stronger medication, such as a nasal spray containing corticosteroids.

Read more about treating allergic rhinitis and preventing allergic rhinitis.

Further problems

Allergic rhinitis can lead to complications in some cases. These include:

nasal polyps – abnormal but non-cancerous (benign) sacs of fluid that grow inside the nasal passages and sinuses

sinusitis – an infection caused by nasal inflammation and swelling that prevents mucus draining from the sinuses

middle ear infections – infection of part of the ear located directly behind the eardrum

These problems can often be treated with medication, although surgery is sometimes needed in severe or long-term cases.