Mar
15
2014

Mold Allergies Often Overlooked

In a recent news story extensive mold infestation was found in a house that had oriented strand boards (OSB) instead of plywood walls. The house also was tightly sealed trapping moisture, which contributed to the extensive mold problem.

Mold problems have been around for centuries, but only in the past few decades allergists  have pointed out to their patients how important it is to prevent this from happening.

In the following I will review a few typical scenarios that can lead to mold accumulation.

1. Mold from airtight house construction

The homeowner described in the link above is not the only case in the world that has a mold problem. Energy efficient homes are popular because they save energy costs; homeowners often also respond to gas companies, electric utility companies and government incentives to convert to airtight home construction.

In the 1980’s the construction industry introduced the cheaper OSB products to replace the more expensive plywood for wall construction. This is often the problem with newer house construction. However, older homes are not immune to mold development.

2. Roof leaks in older homes

Older homes that were built in the 1970’s may have plywood walls and have a bit of airflow from poorer wall construction, which would prevent mold formation. But roofs are older and do not always get replaced right away when a leak is detected. It may even take some time in areas where there is less precipitation before it is picked up during a particularly heavy rainstorm. Water that enters from a leaky roof can form a puddle on top of the ceiling where mold softens the drywall material until a leak in the ceiling causes water to drip down onto the floor. The mold spores multiply particularly well in wall-to-wall carpeting, but OSB material is also a good growth opportunity for molds due to the mini air spaces between the glued wood pieces. Plywood with its several tight layers is much more resistant to water penetration and mold growth.

Mold Allergies Often Overlooked

Mold Allergies Often Overlooked

3. Mold growth after hurricanes

After hurricane Sandy images of “black mold” were frequently shown in the media. The problem is that after 48 hours anything that was in contact with water produces mold. However, often with disasters like hurricanes there are evacuation orders and you cannot return to your home for several days. There may be further delay because there is a waiting period for insurers to assess the amount of damage, before you can clean all surfaces affected by mold.

The end is result often that expensive mold sanitation is needed or the person ends up moving away and the house is levelled before a new house can be built.

4. Effects of molds

People with preexisting allergies and asthma are more susceptible to the effects of molds. It leads to itchy eyes, wheezing, coughing, and exacerbation of asthma.

Here is a brief overview what the CDC is stating about mold. This site also explains that you can recognize a mold problem because of a musty smell or foul stench in the air and because of the appearance (discoloration of ceilings or walls, water damage).

You can clean hard surfaces with bleach water. Bleach kills molds, but it may have to be cleaned several times within a few days to get rid of the last spores. Whatever cannot be sanitized in this way must be removed or replaced.

5. Health concerns regarding molds

Ref. 1 reviewed the public concern about the toxic effects of molds. It noted that with the Internet and the popular press having exaggerated some of the connections of symptoms with mold allergies, the term “mold madness” has been coined (Ref.2). Despite the paranoia in the general public about toxins from molds, there is only a small percentage of the population that is sensitive to molds where IgE antibodies and IgG antibodies against molds can be determined through blood tests. These individuals often are also allergic to other environmental allergens like grass pollen and dust mites. The asthmatic reactions in sensitive people are not as severe as what peanut traces would do to peanut sensitive patients, but skin testing and blood test screening for specific IgE and IgG antibodies do often confirm that sensitive people indeed can have specific mold allergies. In the vast majority of people these tests are negative and correlations between mold infestations and allergic reactions could not be verified (Ref.1).

6. Fixing mold damage and dealing with allergies

It follows from this that you should remove any visible molds and fix whatever the cause was for its appearance. Carefully disinfect the areas with diluted bleach water (the CDC recommends 1 cup of bleach per 1 gallon of water) several times. Make sure the areas are dry and not musty otherwise you  have  work on improving ventilation. If you are not one of these hypersensitive persons, there is nothing to worry further. However, if you are hypersensitive an allergist should examine you. Common indoor molds that cause the so-called “immediate type hyper reactivity” are due to the mold species Aspergillum and Penicillium. Most outdoor molds that can cause problems for sensitive people are due to Alternaria and Cladosporium species. The latter would be the ones found in carpets after a leaky roof has caused problems. When the allergist has found specific allergies to one or several of the mold species, allergy shots may be prescribed that would have to be given weekly to the sensitive person who was found to have environmentally induced asthma. Often it takes several years for these desensitization shots to stop the affected person from reacting  to molds. In some cases patients need to stay on these shots life-long.

Conclusion

The key with regard to mold allergies is to prevent mold growth by being vigilant about detecting early problems with leaky roofs, walls and cleaning up water damage right away. When there is a musty tell- tale smell, investigate right away and remedy the problem. For most people this is the end of the story. However, a small percentage of very sensitive people need to consult with an allergist who should investigate whether or not these people would benefit from allergy injections.

In some rare cases the affected person may have to relocate to another house that is free from molds.

More information about asthma: http://nethealthbook.com/lung-disease/asthma-introduction/

References

1.Shannon: Haddad and Winchester’s Clinical Management of Poisoning and Drug Overdose, 4th ed. Copyright 2007 Saunders

2. Zacharisen MC, Fink JN: “Is indoor “mold madness” upon us?” Ann. Allergy Asthma Immun. 2005; 94:12-13.

Last edited Nov. 7, 2014

Apr
14
2013

Allergies Not Only In Spring

Springtime is the time of spring allergies: those affected develop a runny nose, itchy eyes and in more severe cases they may experience a flare-up of asthma. Allergies can be triggered by the increase of pollen counts in the air that occurs every spring. In those who are sensitive, this leads to antibody formation in the blood. But often people have not only sensitivities to the pollens of spring bloomers; they may also be allergic to spores from molds, to dust mites and may have underlying allergies to foods. The immune system has memory cells that memorize that a person has had an allergic encounter to one of these items in the past, and allergic reactions can become more significant with a future encounter. Allergies can also be made worse when a person has food sensitivities and there are cross reactions between pollens of trees or grasses that can share surface protein regions with similar protein regions in foods.

It is known that cross allergies are possible between birch pollen and apple, carrots or hazelnut. In its extreme form allergies due to antibodies, called IgE antibodies, can cause anaphylaxis. A person presensitized by inhaling birch pollen, after eating an apple, hazelnuts or a carrot can develop itching of the throat, swelling of the lips and very quickly deteriorate getting into an anaphylactic shock.

Other cross allergies exist between ragweed pollen, which is a powerful inhalant allergen and melons or bananas. Again there are specific IgE antibodies that are responsible for this immune reaction. In this case the ragweed allergy primes the immune system to produce IgE antibodies, which are potentiated by certain foods that share similar protein components as the ragweed pollen.

In the following I will deal with inhalant allergies separately from food allergies.

Allergies Not Only In Spring

Allergies Not Only In Spring

Inhalant allergies

Inhalant allergies are easier to diagnose and to treat than food allergies. Your doctor will likely refer you to an allergist when you have allergies that do not respond to treatment with intermittent over the counter antihistamines. Your symptoms may come on in the spring with itchy eyes and a runny nose. From year to year you find that you become more and more dependent on antihistamines and nose drops to unplug your nose. The allergist likely will do sensitivity tests, which consist of skin prick or scratch tests on the back or the forearms.

In more serious allergies, where the patient has coughing and wheezing attacks following allergic reactions, the allergist may suggest to start intermittent allergy injections alongside the standard inhalation therapy for asthma. An allergy serum is prescribed where the lab mixes ingredients based on all of the positive tests that led to a strongly positive skin reactions when allergy testing was done. Typically the family doctor or his nurse will start the allergy injections initially in weekly intervals, later when the maintenance dose is reached, it may be modified to injections every 10 to 14 days.

The allergy injections stimulate the immune system to produce harmless competing antibodies, which counteract the disease producing allergic antibodies. In the process of desensitization shots the immune system will normalize, which means that the inflammatory response of the immune system settles down to normal.

This is not the end of the story with inhalant allergies. The patient needs to be retested on a yearly basis by the allergist. The immune system changes all the time as new allergies can develop and old ones may go away.

Retesting is necessary to keep track of what is going on and to change the composition of the allergy serum. Those patients who are working together with the allergist can do very well, and often they gradually outgrow their allergies. Others may not be so lucky. They may have reactions to the allergy injections. In these cases avoidance of what causes the allergy may be the only solution to treat the allergies.

There is an alternative to allergy injections, which has been used in Europe, namely a sublingual immunotherapy. Recently there has been a review of the literature for FDA approval that is needed for oral desensitization for ragweed, dust mites, grass pollen and cat dander. It will take some time before the FDA approval process will become a reality for sublingual desensitization in the US.

A special form of inhalant allergies are allergies to pets (mainly dogs and cats, but also allergies to petting zoo animals). The dander that the human comes in contact with is a protein contained in the animal hair. It causes hives when it touches the skin. This occurs as the dander is absorbed through the skin and meets the local mast cells that release histamine. This in turn is responsible for the hive formation. Sneezing and even asthma can develop from inhaled protein particles that reach the lungs. Allergy injections for the treatment of animal dander allergies are very limited as they often do not help or make the allergies worse. Avoidance of animal contact is usually what the allergist recommends as the solution, a recommendation, which often is not appreciated by the affected animal lover.

Food allergies

Often we eat  some foods more frequently, because they are our favorites. This means that our gut lymphocytes that get in contact with these foods can start to react to one or more of the foods we ingest. At this time we may experience abdominal cramps, diarrhea, vomiting and a host of other possible symptoms.

The physician will tell the patient that testing for food allergies is a problem as most of the usual skin tests employed for inhalant allergies do not reliably work in determining food allergies. The doctor will ask the patient or the mother of the child with food allergies to keep a food diary and keep track of the allergic symptoms in the diary as well. An elimination diet will have to be devised based on the information gathered in the diary as it becomes clear from that record which foods cause which symptoms. The foods causing allergic symptoms are subsequently eliminated. This is a cumbersome process, but it is the most reliable method of testing and treating food allergies.

In the past there was a blood tests, called RAST test, which tested for common food allergies that can cause severe allergic reactions like egg, milk, peanut, tree nuts, wheat, crustacean shellfish and soy. Since about 2010 this has been replaced by the more sensitive ImmunoCAP Specific IgE test.

Children often develop food allergies to egg, milk, wheat, nuts, peanuts and soy, which are food allergies with positive IgE tests. When they age, their immune system develops tolerance to many of these foods and they often outgrow these allergies.

There are other popular lab tests where a blood drop is analyzed with IgG, IgM and IgE antibodies against a panel of foods. A number of suppliers offer these tests.  However, the specificity, sensitivity and reliability can pose problems with regard to the interpretation of the results: allergists often point out that a test may be a false positive when a person likes certain foods and IgG antibodies against this food show up despite the patient having no symptoms. Another specialist may interpret this to indicate that the body shows early sensitization to a certain food, but clinically it is not yet obvious. In other words the sensitivity of the test is so high that it undermines the validity of the test. Recently a panel of international scientists reviewed the validity of these IgG based food intolerance tests and they found the tests not reliable.

The immune responses to food allergies are complicated as there are immediate type immune reactions and delayed type immune reactions. The immediate immune responses are investigated with the above mentioned ImmunoCAP Specific IgE test. The delayed immune responses can be measured using the ELISA test.

Other considerations about allergies

You see from this discussion that a patient with allergies needs a properly trained allergist who will do a comprehensive analysis involving a thorough history, examination, blood tests and immune tests.  The test results have to be interpreted with the experience and the clinical judgment of the specialist.

Since the 1970’s when Clearfield wheat was introduced around the world on a large scale, which has a much higher gliadin (gluten) content than the old wheat varieties. As a result of exposure to this new type of wheat gluten intolerance and leaky gut syndrome have increased substantially in the world population. Genetically modified foods like soy, corn, sugar beets, canola and more have challenged the immune system of sensitive humans even more to an extent, which is not fully understood yet. We do know that some people can develop autoimmune diseases and this may be the reason that a host of diseases that belong into this disease category (MS, rheumatoid arthritis, Hashimoto’s thyroiditis, ankylosing spondylitis etc.) are much more common now than in the past.

After food elimination for 2 to 12 months depending on the severity of the food allergy, your body may have eliminated the allergy to the food you have avoided, in other words your body built up tolerance. Before you expose yourself to any food that you used to be allergic to and that you want to re-test, it is best to have an EpiPen ready in case your allergy has not resolved. Caution is necessary with regard to foods that cause more severe allergies, e.g. shellfish or peanuts, which may last life long. It is safer to avoid these foods that cause more severe allergies altogether.

Allergic reactions of the immune system belong into the category of chronic inflammatory diseases. These are known to be the root of chronic diseases like asthma, arthritis, heart disease, high blood pressure and cancer. When you are vigilant about allergies and get proper assessment and treatment by an allergist, you will prevent serious health problems including the above mentioned chronic diseases.

More on asthma, which is a chronic inflammatory lung condition, often associated with multiple environmental allergies:

http://nethealthbook.com/lung-disease/asthma-introduction/

Last edited Nov. 6, 2014