Shoe Allergy Dermatitis
If you are experiencing itchiness on your feet that does not respond to treatment, you may have a shoe allergy. Such feet allergies are common, yet the symptoms are often overlooked or misdiagnosed, says Cleveland Clinic dermatologist James S. Taylor, M.D.
Shoe allergy is a form of contact dermatitis, which is inflammation caused by contact of the skin with a particular substance. The rash is often confined to a specific area and has clearly defined boundaries. The allergy can cause red and swollen skin that may blister. Shoe allergy is often confused with atopic dermatitis, a chronic itchy inflammation of the skin that is common in people who have hay fever or asthma. There are two types of contact dermatitis. In the irritant type, exposure to substances such as soaps, detergents or metals may irritate the skin. In the allergic type, exposure to a substance is the cause, but the initial exposure or even numerous subsequent exposures will not cause an allergic reaction.
Allergic contact dermatitis of the foot develops over time, as the skin of the foot is repeatedly exposed to an allergen, a substance that causes an allergic reaction. "Building an allergic reaction can take years," notes Dr. Taylor, who heads the Clinic’s section of industrial and environmental dermatology, and writes and lectures on shoe allergies. "So it’s not unusual for someone to ‘suddenly’ become allergic to a substance they’ve had contact with for a long time."
Diagnosis can be trickyThe most common shoe allergens include rubber, chemicals used in tanning leather, and adhesive materials and dyes. Sometimes metal buckles or shoelace grommets may cause contact allergy. Sport shoes are often implicated in shoe allergy, although this may be because they are widely worn by many people. Footwear that keeps feet in a warm, moist environment—work shoes are a good example—are common culprits. Sandals, on the other hand, are less often associated with shoe allergy. Their open design allows feet to "breathe," and there isn’t as much shoe material to irritate the feet.
Because allergic contact dermatitis can be difficult to distinguish from other rashes, the diagnosis can be elusive. A skilled dermatologist will use the location of the rash to help identify shoe allergy. For example, dermatitis on the sole of the foot points to an allergy to the insole or shoe lining. A rash on the top of the foot suggests an allergy to the shoe upper. Dermatitis between the toes, however, is likely caused by a bacterial or fungal infection, says Dr. Taylor.
Patch testingIdentifying the specific allergen can be challenging, and patch testing is the procedure useful in making the diagnosis. Patch tests are performed by applying small amounts of potential allergens directly onto the skin with tape. The tape strips are removed after 48 hours. A reaction is characterized by a small red spot that appears at the patch site.
"If the allergen can be identified and avoided, most shoe allergies can be cleared up completely," says Dr. Taylor. In some patients, treatment may include medication to control excessive sweating, since sweat can aggravate dermatitis.
© Copyright 1995-2005 The Cleveland Clinic Foundation. All rights reserved
Shoe allergy is a form of contact dermatitis, which is inflammation caused by contact of the skin with a particular substance. The rash is often confined to a specific area and has clearly defined boundaries. The allergy can cause red and swollen skin that may blister. Shoe allergy is often confused with atopic dermatitis, a chronic itchy inflammation of the skin that is common in people who have hay fever or asthma. There are two types of contact dermatitis. In the irritant type, exposure to substances such as soaps, detergents or metals may irritate the skin. In the allergic type, exposure to a substance is the cause, but the initial exposure or even numerous subsequent exposures will not cause an allergic reaction.
Allergic contact dermatitis of the foot develops over time, as the skin of the foot is repeatedly exposed to an allergen, a substance that causes an allergic reaction. "Building an allergic reaction can take years," notes Dr. Taylor, who heads the Clinic’s section of industrial and environmental dermatology, and writes and lectures on shoe allergies. "So it’s not unusual for someone to ‘suddenly’ become allergic to a substance they’ve had contact with for a long time."
Diagnosis can be trickyThe most common shoe allergens include rubber, chemicals used in tanning leather, and adhesive materials and dyes. Sometimes metal buckles or shoelace grommets may cause contact allergy. Sport shoes are often implicated in shoe allergy, although this may be because they are widely worn by many people. Footwear that keeps feet in a warm, moist environment—work shoes are a good example—are common culprits. Sandals, on the other hand, are less often associated with shoe allergy. Their open design allows feet to "breathe," and there isn’t as much shoe material to irritate the feet.
Because allergic contact dermatitis can be difficult to distinguish from other rashes, the diagnosis can be elusive. A skilled dermatologist will use the location of the rash to help identify shoe allergy. For example, dermatitis on the sole of the foot points to an allergy to the insole or shoe lining. A rash on the top of the foot suggests an allergy to the shoe upper. Dermatitis between the toes, however, is likely caused by a bacterial or fungal infection, says Dr. Taylor.
Patch testingIdentifying the specific allergen can be challenging, and patch testing is the procedure useful in making the diagnosis. Patch tests are performed by applying small amounts of potential allergens directly onto the skin with tape. The tape strips are removed after 48 hours. A reaction is characterized by a small red spot that appears at the patch site.
"If the allergen can be identified and avoided, most shoe allergies can be cleared up completely," says Dr. Taylor. In some patients, treatment may include medication to control excessive sweating, since sweat can aggravate dermatitis.
© Copyright 1995-2005 The Cleveland Clinic Foundation. All rights reserved
posted by Madison @ 10:59 AM
<< Home