Shoe Allergies
Shoe allergies are a form of allergic contact dermatitis, in which the skin on the feet reacts to particular substances found in shoes (allergens).
Common allergens in shoes include:
leather chemicals (particularly potassium dichromate)
rubber chemicals/accelerators (particularly MBT and thiuram mix chemicals)
dyes (particularly PPD)
metal components/decorations on shoes (particularly nickel sulfate and cobalt chloride)
Shoe allergies develop over time, as the skin on the feet is repeatedly exposed to a certain allergen; it is not unusual to suddenly become allergic to a substance.
Symptoms of shoe allergies include:
inflammation
swelling
redness
blisters (that can break and leave crusts and scales)
fissuring (cracks in the skin)
burning
pain
itchiness
secondary infection
With long term exposure to an allergen, the skin can become thick, red and scaly.
Symptoms are usually found on the tops of the foot and toes. They can also be found on the sole of the foot, the legs, and the sides of the feet and heels. The area in-between the toes is not usually affected. Topical corticosteroids are often prescribed as treatment: they relieve itching and reduce inflammation.
Shoe allergies are hard to diagnose, as there are a number of other diagnoses that the doctor must consider (including irritant contact dermatitis, atopic eczema/dermatitis, bacterial or fungal infections, dyshidrosis, psoriasis, lichen planus and even allergic contact dermatitis resulting from something other than shoes (socks, cosmetic products, etc.)). Patch tests are used to make the diagnosis.
References
'Allergic Contact Dermatitis', http://dermnetnz.org/dermatitis/contact-allergy.html, Accessed 23 April 2007.
'Allergic Contact Rashes', http://www.aad.org/public/Publications/pamphlets/AllergicContactRashes.htm, Accessed 20 April 2007.
Susanne Freeman (1997), 'Shoe dermatitis', Contact Dermatitis 36 (5), 247–251.
Catherine R. Holden, David J. Gawkrodger (2005), '10 years' experience of patch testing with a shoe series in 230 patients: which allergens are important?', Contact Dermatitis 53 (1), 37–39.
'Oh, My Itching Feet', http://www.clevelandclinic.org/health/health-info/docs/3100/3182.asp?index=11059&src=news, Accessed 20 April 2007.
Meltem Onder MD, Asena Cigdem Atahan MD, Banu Bassoy MD (2004), 'Foot dermatitis from the shoes', International Journal of Dermatology 43 (8), 565–567.
A. Nardelli, M. Taveirne, J. Drieghe, A. Carbonez, H. Degreef, A. Goossens (2005), 'The relation between the localization of foot dermatitis and the causative allergens in shoes: a 13-year retrospective study', Contact Dermatitis, 53 (4), 201–206.
Zahida Rani, Ijaz Hussain, Tahir Saeed Haroon (2003), 'Common allergens in shoe dermatitis: our experience in Lahore, Pakistan', International Journal of Dermatology, 42 (8), 605–607.
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