Foot rashes have many underlying causes. Some foot rashes affect only the toes or heels, while other conditions can occur on the tops or bottoms of feet. Skin rashes that affect the whole foot may be chronic. See your doctor for an accurate diagnosis if you develop a foot rash.
Allergic contact dermatitis causes pale pink skin or red scaly rashes and blisters. Lesions usually have distinct edges that are straight or at right angles. One of the most common causes of allergic contact dermatitis on the feet is a sensitivity to chromates, which are a common ingredient in shoe leather. Other causes can include exposure to dyes or soap, antibacterial cream that contains neomycin and other products that contain nickel, lanolin or formaldehyde. Poison ivy causes dermatitis in those sensitive to plant. Treatment can consist of antihistamines or topical steroid medications. Prescription steroids, such as prednisone, are also prescribed for severe cases.
Athlete's foot is caused by a fungal infection on the foot that is passed from humans and animals. Areas such as locker rooms and fitness centers often carry this foot fungus, which is highly contagious. Red, scaly patches typically appear between the toes or on the soles or tops of the feet. Athlete's foot causes a ring-shaped rash -- called tinea pedis. Athlete's foot usually is treated with over-the-counter antifungal medications or prescription-strength creams. Creams that contain urea or lactic acid can be used to dissolve the scaly rash so the medication can penetrate the skin and topical lotions containing aluminum chloride can be applied to reduce swelling.
Foot rashes may become chronic. Medical conditions such as psoriasis may cause skin outbreaks precipitated by emotional stress, infection, injury to the foot or various medications. Typical lesions are red scaly rashes with a silverish color on top. They may be present under the toenails. Topical steroids are the most common treatment for these rashes.
Infections can cause foot rashes. One type of infection, called scabies, is a highly contagious infection caused by a miniscule mites. Red, patchy rashes can develop all over the body but usually appear prominently on the hands and feet. Scabies are rampant in hospitals, daycare centers and prisons. The human immune system is sensitive to the Sarcoptes scabiei bug. Scabies rashes appear at first as small bug bites or pimples with scabs on them. A thread-like black line, usually next to the rash, indicates where the mite is burrowing. Scabies rashes are extremely itchy. Medicated lotion prescribed by a doctor must be applied to the entire body to kill any lingering eggs and mites that have burrowed away from the feet.