Skin problems
The skin of the foot can present with a variety of problems. Rashes may represent athletes foot, or they be a form of eczema or dermatitis. Calluses may be just local hyperkeratotic tissue, or they may actually be warts. Skin or lesion discoloration could be due to a bruise or hyperpigmentation, or it could be melanoma. In fact, squamous cell carcinoma is the most common form of malignancy to present below the knee. Rashes, growths, lesions, or skin discolorations which don't resolve should all be evaluated by a medical professional familiar with the foot. Proper medical assessment will lead to appropriate and effective treatments.