Shoe allergy

Shoes and allergies

Allergy to chemicals used in shoe production is found in approximately 5% of eczema patients tested for allergies. However, this percentage can vary greatly.

 

In Germany the number of women with allergy from footwear has increased over the recent years. Shoe allergy is also seen in children. The main symptom is eczema where the skin is red and itchy with spots or bumps and possibly blisters. The symptoms appear first on the area of the foot that has been in contact with the piece of shoe containing the allergen. Typically, allergies from leather in the upper shoe begin on the back and top of the foot, and allergies from adhesives in the sole of the shoe begin on the foot sole. Eczema on only the toes is likely to be an allergic reaction to material used to reinforce the toe of the shoe. The eczema will nearly always be on both feet.

 

Causes of allergy to footwear

Many different materials are used in the production of shoes, and shoe retailers often have no knowledge of the chemicals in the different shoe components.

The most frequent cause of allergy to footwear is rubber chemicals. These are used in rubber shoes, in adhesives, and in various finishes on leather shoes and rubber soles. Chrome is another frequent cause of allergy. Chrome is a metal and the salt from this metal has long been used in tanning leather. It ensures elasticity and durability; untreated leather is not durable. The tanning process can be regulated to limit the release of the allergenic chrome when the end product is used. Nevertheless, chrome is a frequent cause of shoe allergy. The Danish Environmental Agency has tested a number of products for chrome release. Five shoes were among those products; two of those five shoes released chrome in amounts that could lead to allergies. It is not possible to know from its appearance whether leather releases chrome in harmful amounts. There are leathers that are tanned with plant extracts instead of chrome, vegetable-tanned leather.

Adhesives used in shoes, for example, to fix the sole, can cause allergies. The dyes used for various parts of the shoe can also cause allergies. Preservatives, too, can cause allergies, for example formaldehyde, which prevents bacterial growth, may be used in the different materials for the shoe–in the adhesives, in treatment of the leather, in the textiles etc.

What can you do?

If you have eczema on your feet you should be tested for footwear allergy by a dermatologist.

Eczema on the feet may come from other causes, for example, atopic dermatitis (childhood eczema) or a fungal infection. A dermatologist will be able to diagnose what type of eczema you have. If the eczema on your feet is caused by an allergy, you should avoid the material containing the allergen. You may need specially made shoes, particularly if you are allergic to chrome or adhesives. It may also be necessary to allergy test the adhesive and/or leather to be used in any specially made shoes. Subsidies are available for two pairs of specially made shoes per year. For this, you need to apply to your municipality with a letter from your doctor about your allergy.

The EU Commission plans to introduce standards governing the amount of allergenic chrome released from leather. The Knowledge Centre for Allergies has started up a research project to find out what amounts of chrome lead to allergic reactions. The results, which will be taken into account in the coming legislation, will help prevent chrome allergies, for example, chrome allergies cause by footwear.

This article appeared in the journal "Astma-Allergi bladet"