Different parts of the feet can be affected by various kinds of rashes, report researchers at Skinsight, a physician-run website on skin disorders. Some foot rashes affect only the toes or heels, while other conditions can strike on the tops or bottoms of feet. Skin rashes that affect the whole foot, such as dermatitis or psoriasis, can be chronic. Other rashes occur after exposure to chemicals.
Allergies
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 prescribed for severe cases.
Athlete's Foot
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 can contain athlete's foot fungus, which is contagious. Red, scaly patches typically appear between the toes or on the soles or tops of the feet. Doctors at the Mayo Clinic report that the ring-shaped rash of athlete's foot, also called tinea pedis, is similar to the rash produced by ringworm. 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.
Psoriasis
Psoriasis is a chronic condition that is non-contagious and affects nearly 3 percent of the population. The skin rash is a lifelong condition that usually runs in families. Outbreaks can be precipitated by emotional stress, infection, injury to the foot or various medications. Typical psoriasis lesions are red scaly rashes that have a silverish color on top. They may be present under the toenails. Topical steroids are the most common treatment for psoriasis.
Scabies
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.
