Definition
A rash on the foot can have many different causes. The appearance of the rash can vary greatly. The most common places where a rash on the foot develops include the back of the foot, the sole of the foot, and the spaces between the individual toes. The rash usually spreads over a large area and reddish or white patches appear on the affected areas, which can appear either flat or raised. In addition, fluid-filled blisters or purulent pustules can also appear, from which scales, crusts, as well as cracks in the surface of the skin develop in the course of the rash.
Causes of a rash on the foot
Skin rashes on the foot are usually the result of an infection or a defence reaction of the body to invading pathogens such as bacteria, viruses or fungi. Possible infections include measles, chickenpox, hand-mouth-foot disease, herpes or athlete’s foot. Also an intolerance of certain drugs, allergies or contact with harmful substances can lead to the development of a rash on the foot.
Heavy or excessive sweating can contribute to the development of a rash on the foot in many people. Wearing sports shoes, heavy sweating of the feet can lead to a sweat accumulation because the sweat cannot evaporate sufficiently. Irritations of the skin can occur at all points where the skin rubs against each other.
If the sweat cannot evaporate, it accumulates and creates an optimal medium for bacteria and fungi to accumulate and multiply. It also opens the pores of the skin, allowing pathogens to enter undisturbed. The salts contained in sweat dry out the skin.
Diagnosis
In order to correctly diagnose a rash on the foot, it is important to know when the rash started and how it has changed over time. Existing allergies, general or skin diseases, as well as recent medication can also provide crucial information about the cause of the rash. In the area of the feet, an outgoing clinical examination should be performed and it is advisable to take a smear to identify the possible pathogens. Depending on suspicion, allergy tests or further blood tests can be performed.
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