How To Handle Contact Dermatitis In Athletes
Running shoes and athletic gear contain rubber accelerators, antioxidants and other rubber additives that are common causes of contact allergy. Among the potential allergens are thioureas, thiurams, carbamates, N-isopropyl-N-phenyl-p-phenylenediamine (IPPD) and mercaptobenzothiazole (MBT). It has also been reported that the dye found in the insoles of certain running shoes has caused contact dermatitis in runners. Allergen alternatives include shoes made mostly of polyurethane and those with components that are patch-test negative.
Swimmers and divers are exposed to numerous rubber-containing articles such as masks, goggles, diving suits, fins and fin straps. Scuba-diver dermatitis may be caused by IPPD, thiuram and p-phenylenediamine black rubber antioxidants. In wetsuits, rubber accelerators are the most important allergens. Of these, diphenylthiourea was identified as having the highest overall sensitization potential. For thiourea-sensitive individuals, Rubatex Corporation manufactures a grade of closed-cell neoprene without thiourea.
Be Aware Of Possible Plant Allergens
Outdoor exercise exposes athletes to plants, which are among the most common causes of contact dermatitis. When patients present with suspected contact allergies, you should ask them about their contact with plants. The Rhus plants, which include poison ivy, oak, and sumac and contain the allergen urushiol, are the most common cause of allergic contact dermatitis in North America. Their resins remain allergenic and, since they do not evaporate, may cling to clothing, sporting equipment and pets for months. Even in the winter, the stem and dead leaves may carry the resins. Contact with these resins results in a rash that most commonly appears on exposed skin as linear streaks with vesicles. The blister fluid does not contain the resin and does not spread the condition.
Plant extracts are now popular in topical medications and cosmetics. Athletes using these “natural remedies” are particularly susceptible to the development of contact allergy. There are reports of allergic contact dermatitis with witch hazel, which is used as an antipruritic; tea tree oil, a eucalyptol-containing anti-acne/fungal treatment; and chamomile, an essential oil with presumed sedative and antiinflammatory effects.
When Topical And Oral Medications Can Cause Allergic Dermatitis
Medications, particularly topical agents, are often responsible for localized or generalized allergic dermatitis. Almost any topical antibiotic can produce contact allergy with neomycin and bacitracin being among the most common perpetrators. Topical acyclovir and imidazole antifungal agents are also potential antigens. Topical anesthetics (eg., benzocaine) and topical antihistamines (eg., diphenhydramine, doxepin) may cause allergic contact dermatitis. Diphenhydramine can also act as an occasional photosensitizer. Methylsalicylate, a topical analgesic, can cause both an irritant and allergic dermatitis in athletes.
Athletes who are allergic to sunscreens containing p-aminobenzoic acid (PABA) may have a cross-reaction with benzocaine, p-aminosalicylic acid, sulfonylurea antidiabetic agents, procainamide or thiazide diuretics. Oral medications taken by athletes may also be allergenic. This is particularly the case with nonsteroidal agents, especially piroxicam, and antibiotics such as ciprofloxacin, nalidixic acid, sulfonamides and tetracyclines, which are photosensitizers.
Contact dermatitis is also frequently caused by over treatment with topical medications for tinea pedis and hyperhidrosis, and overuse of lotions and creams for softening callosities.