How To Handle Contact Dermatitis In Athletes
Whenever an athlete presents with an acute vesicular or chronic scaling inflammatory condition of the skin, one must consider contact dermatitis. Often, the activities of these athletes may lead the practitioner to an initial diagnosis of conditions such as friction trauma, infection and pedal hyperhidrosis while treatment of the actual condition, contact dermatitis, is significantly delayed. Contact dermatitis can manifest itself in several ways, including primary irritant contact dermatitis, allergic contact dermatitis and photoallergic contact dermatitis.
Irritant contact dermatitis is the non-allergic type that arises from mechanically or chemically irritating substances. Since this condition is not immunologically mediated, the concentration of an irritant must exceed a threshold before the reaction can take place. This threshold may be very high, according to the irritancy of the compound. Since sensitization is not necessary, an irritant reaction may occur immediately after the athlete comes in contact with the material. Irritant contact dermatitis may be caused by adhesive tape, topical medications, antiseptics, insect repellents, cosmetics, oily sunscreens or a leakage of “cold-pack” chemicals.
Allergic contact dermatitis, in contrast, is a delayed T cell-mediated immune response to the antigen, usually a low-molecular weight hapten (see “Sources Of Allergenic Contact Dermatitis In Athletes” below). Unlike irritant contact dermatitis, this condition has an induction period of five to seven days before the first appearance of hypersensitivity. The peak reaction of the skin occurs 24 to 48 hours after being challenged with the same antigen. This manifests in inflammation and formation of small pruritic vesicles and papules.
If the reaction is severe, the vesicular phase may proceed to bullae formation. If one removes the sensitizing agent, the skin soon heals within a short period of time. When there is repeated exposure to the causative agent, the skin reaction becomes rapid and severe.
One factor that exacerbates allergic contact dermatitis is repeated exposure to heat or constant warmth which may occur within a shoe. This causes increased perspiration, which allows the well-recognized sensitizers within shoe materials to become problematic, and promotes the spread of the vesicular or pruritic papules. Be aware that the general appearance of these papules may lead to the misdiagnosis of tinea pedis. Appropriate treatment of contact dermatitis is frequently delayed because of this misdiagnosis and long-term treatment with topical antifungal agents.
It is often difficult to tell the difference between irritant contact dermatitis and allergic contact dermatitis. In general, allergic contact dermatitis appears more polymorphic, with erythema, vesiculation and edema. Irritant contact dermatitis is generally localized and looks more like a severe burn with large blisters or marked erythema and edema.
Photodermatitis (photoallergic contact dermatitis) is less common than the other two forms of contact dermatitis. It can occur when one applies certain topical agents to the skin of the lower extremities before sun exposure. This type of eruption can be mediated by the T-cell system. If the problem is not immunologically mediated yet sunlight is still required to activate the condition, it is known as a phototoxic reaction.
Identifying Possible Sources Of Contact Dermatitis
Athletic tape, especially that which is rubber-based, has been identified as the most common contact allergen among athletes. Rubber-based tape is now frequently replaced with tape made of cloth and other adhesives, such as p-Tert-butylphenol formaldehyde resin (PTBP-FR) and acrylics, because of their durable, flexible and rapidly adherent qualities.
Nickel is the most frequently identified allergen of patients undergoing patch testing. Athletes are probably predisposed to nickel allergy. The significant factor in its development is not so much the nickel concentration in the object or coating but the amount released into the skin during exposure to human sweat. The dermatitis appears at contact sites of metal chains, buckles, clasps and other gold-plated items first covered with nickel.