Avoid These Eczema Triggers

Atopic eczema is a common skin disease especially among children and young adults. It is characterized by itching, dry scaly skin, inflammation, lesions, skin infections and even bleeding skin ulcers.

A number of causes have been proposed for eczema. As scientists study the development and progression of the disease, it is clear that it has a strong genetic component and that it involves the immune system.

In addition, eczema is linked to the type of bacteria growing on the skin and in the gut as well as to the state of the physical barriers of the skin and the gastrointestinal tract.

Besides bacteria and genes, food allergies are known to cause (or at least, worsen) atopic eczema.

Environmental factors are also important causes of eczema. Air-borne and contact allergens found in the environment can trigger hypersensitivity reactions in susceptible individuals. These allergens are responsible for a number of allergic diseases including asthma and hay fever.

Once the first contact with these environmental allergens sensitizes the body, subsequent contacts can trigger allergic reactions which can cause itching and skin inflammation.

Discussed below are the most important environmental allergens that can trigger an eczema flare-up.

1. House Dust Mites

House dust mites are very tiny animals commonly found in homes. They are not visible to the eye and thrive mostly in places with high humidity such as the kitchen and bedroom.

The two common species of dust mites are the European house dust mite or Dermatophagoides pteronyssinus and the American house dust mite, Dermatophagoides farinae. Notwithstanding their names, these mites can also be found in other locales besides Europe and America.

Dust mites feed on dead skin shed from humans, hair, fingernails, animal furs, pollen, bacteria, and fungi.

Multiple studies have confirmed that dust mites can cause and/or worsen asthma and other allergic diseases such as eczema.

There are different ways by which dust mites can trigger eczema. While the exoskeleton of the mites can cause allergic reactions, the digestive enzymes left in their fecal droppings can also trigger hypersensitivity reactions in those who are sensitive to dust mite allergens.

At least 15 mite allergens are known. These are classified into different groups but the most important ones are found in Group 1 and Group 2.

Group 1 dust mite allergens are digestive enzymes such as proteases while Group 2 allergens are resident on the mites.

The major dust mite allergens belong in Group 1. These are Der pI and Der pII. Because these allergens can persist even after the mite shedding them is dead, efforts to kill off dust mites may not provide immediate relief for eczema sufferers.

Type I Hypersensitivity Reaction

The first step in the process by which dust mites trigger allergic reactions is sensitization through first exposure.

Epidemiological studies indicate that as many as 1.2 billion people have chronic sensitization to dust mites all over the world.

Although the exact mechanism involved in sensitization to dust mite allergens is not clear, scientists have demonstrated that it involves the immune system producing antibodies against tagged dust mite antigens. The main antibody produced against mite allergens is the immunoglobulin, IgE.

IgE then binds to certain immune cells such as basophils in the blood and mast cells in the tissues.

Upon second exposure to dust mite allergens, the body releases antibodies against the “foreign substances” and this leads to the release of leukotrienes, prostaglandins, and histamine from basophils and mast cells.

When these pro-inflammatory factors are released in the tissues of the skin, they cause inflammation (reddening of the skin and hives) and pruritus (itching).

Since these are the major presentations of atopic eczema, house dust mites can worsen chronic eczema or even bring it out of remission.

Type IV Hypersensitivity Reaction

Besides triggering immediate skin reactions, studies show that dust mite allergens can cause type IV hypersensitivity reactions. This is a delayed immune reaction with a different course of action.

This allergic reaction also involves the immunoglobulin, IgE. Here, IgE binds to Langerhans cells.

Langerhans cells are skin cells that evolved from a class of white blood cells known as monocytes. When dust mite cells trigger type I hypersensitivity reactions, it raises serum IgE levels. In eczema patients, some of these IgE can be found on the surface of Langerhans cells.

Strangely, asthma patients with high serum levels of IgE do not have IgE bound to their Langerhans cells.

When dust mite antigens reach the Langerhans cells, they activate IgE and are delivered to the lymph nodes where they also activate both arms of the immune T cell line (Th1 and Th2) and their inflammatory mediators.

These mediators are then sent to the skin where they cause itching, swelling, and other eczema symptoms.

Getting Rid of House Dust Mites

Dust mites reproduce too quickly to completely get rid of them. However, you can significantly reduce their population in your home.

Since dust mites need moisture to thrive and feed on the shed human skin, the bedroom and living room (because you stay there the longest) are the most important parts of the house to cleanout. Make sure you ventilate these rooms regularly to lower their humidity and make them unconducive for the mites to thrive.

In addition, you should vacuum regularly especially with a vacuum cleaner equipped with high-powered filters.

Get rid of carpets and rugs as much as you can especially in the rooms most likely to harbor dust. Instead, opt for tiles that are easy to vacuum.

Furthermore, make sure to wash your curtains and beddings regularly. These collect dust and dust mites easily. You should consider getting mite-proof covers for your mattress and pillows.

With regards to pillows, it was once believed that feather pillows would harbor more dust mites than pillows made with synthetic fabrics like polyester. However, studies have shown that the reverse is actually true.

One study found that polyester fiber pillows contain 8 times the dust mite population of feather pillows.

Lastly, you should regularly clean your children’s toys as they can easily accumulate dust and host thriving populations of dust mites.

2. Animal Dander

Animal dander is composed of skin cells shed from pet animals. They are small and light enough to be carried through the air. Therefore, they are aeroallergens.

Any animal with fur or significant body hair can be the source of allergic reactions such as the ones experienced during eczema. Examples of animal dander include the hairs and furs of dogs and cats as well as bird feathers.

Furthermore, cat saliva and bird droppings are other examples of animal dander that are also sources of allergens.

When the body treats the proteins found in animal dander as foreign substances, it develops antibodies against them. This causes hypersensitivity reactions with subsequent exposures.

Animal dander can also house dust mites much like shed human skin cells.

If you suspect that your eczema is due to animal dander, you may need to cut down your pet’s hair/fur and wash the animal regularly too. Alternatively, you may need to get rid of the pet.

3. Pollens

Pollens are also aeroallergens that are dispersed from flowering plants during pollination.

The main route of entry into the body for pollens is the nose. Pollens are more closely associated with asthma and hay fever than with eczema. However, studies show that people with eczema suffer longer from hay fever when exposed to pollens.

Because pollens cause IgE-related hypersensitivity reactions, it can also trigger eczema-like eruptions on the skin. Therefore, pollens can cause itching, swelling, and reddening of the skin.

Skin contact with pollen may also cause dermatitis in susceptible individuals.

To avoid eczema triggered by pollen, you need to avoid sources of pollens. Therefore, if you must keep a garden, make sure not to plant allergen-producing flowering plants and grasses.

In addition, keep your windows shut during the flowering season to prevent the wind from carrying pollen into your house.

You should also take off your clothes when coming into the house and especially into the bedroom. Take regular showers after spending time outdoors to help wash away the pollens that must have settled on your skin and in your hair.

Lastly, you should apply a safe gel such as Vaseline inside your nostrils. This will help trap pollens before they get inside the airways and trigger hypersensitivity reactions.

4. Mold

Mold refers to a broad group of fungi. Molds can grow both indoors and outdoors as long as there is high humidity/moisture or any damp environment. Parts of the house with plumbing, like the kitchen and bathroom, are known to support mold growth.

Mold growth appears with a dusty texture which is really a thick population of spores. These spores are easily carried through the air. Therefore, the mold is also an aeroallergen.

When mold spores are carried through the air, they can settle on the skin or get into the body through the nostrils.

Therefore, molds can cause sinus infections as well as lung infections just as well as it can cause digestive tract infections and skin infections.

Mold can worsen eczema when it settles on the skin and infects eczema lesions. Mold is believed to contribute to discoid eczema or nummular dermatitis. This type of eczema is characterized by the appearance of oval-shaped, itchy skin lesions.

The presence of mold on the skin can change the type of microbes that grow on the skin. This can ultimately lead to the weakening of the physical barrier of the skin.

Besides the mold itself, the mycotoxins it releases can also damage the skin and trigger hypersensitivity reactions that then leads to inflammation.

Mold eczema is often characterized by the reddening of the skin. It is also usually accompanied by a runny nose and other signs of rhinitis.

To avoid mold eczema, you should make sure your immediate environment does not support mold growth. To this end, humidity should be lowered and water damage, in pipes and other building material, should be immediately addressed.

Mold-infested foods should also be avoided. Sometimes, mold growth and mycotoxin contamination may affect foods even though there are no visible signs of decay. Although moldy foods are unlikely to cause eczema, they should still be avoided.

5. Insects

Insect bites can cause eczema-like symptoms such as itchy, red bumps on the skin. While this is not really eczema, it can worsen eczema because it is also caused by an immune reaction that involves the release of histamine and pro-inflammatory factors in the skin.

In fact, one study published in The British Journal of General Practice in 1993 established that people with eczema are more likely to suffer insect bites.

The researchers advised people with a family history of eczema and type I hypersensitivity reactions to using insect repellants when traveling to areas where disease-carrying insects are common.

However, with regards to eczema, cockroach stands out as the one insect to be wary of.

Cockroach Allergy

Cockroach allergy may sound silly but it is actually real, long-established and repeatedly proven by multiple studies.

In 1943, it was first observed that when cockroaches crawled over some people, they developed rashes within hours. Cockroach rash is not only linked to atopic eczema but also to asthma. Studies show that up to 60% of asthmatics also suffer from cockroach allergy.

So, how do cockroaches trigger eczema? Through allergens carried in their saliva, droppings and on their bodies. When left on the skin, these contact allergens cause eczematous lesions.

In one study published in the Journal of Investigative Dermatology, the researchers showed that cockroach allergens were just as potent as dust mite allergens at triggering eczema.

The results of this study showed that cockroach allergens breached the protective barrier of the skin within 3 hours of exposure. Once these allergens got into the skin, they triggered allergic reactions in susceptible individuals.

The antibodies raised against these cockroach antigens caused an inflammatory reaction in the skin. This leads to the red, itchy rash of eczema.

Getting rid of cockroaches is almost impossible. However, you can significantly reduce their population especially if you invite a pest control expert.

In addition, make sure to keep food and garbage covered in order to cut off the insects’ food source.

Lastly, use an excellent barrier cream to protect your skin from direct contact with cockroach allergens.