
In the experience of the guideline working group, a foot ulcer often starts as a blister, as an intracutaneous hemorrhage in callus or subcutaneous hemorrhage in callus, these abnormalities should, therefore, be considered an alarm signal. If no action is then taken with a present ulcer and the patient continues to walk on the foot - due to the reduced sensitivity - healing is not possible due to the continuous biomechanical overload. If an infection subsequently occurs, an amputation of (part of) the foot can sometimes be the only possible treatment.
Many patients with a foot ulcer also have standing abnormalities of the foot or exostoses. This puts an abnormal load on the skin and underlying tissues. In a follow-up study, 66% of all patients who developed a foot ulcer had foot defects, while these abnormalities were present in only 37% of patients who did not develop an ulcer. Claw or hammertoes can lead to increased plantar pressure at the heads of the metatarsal or interdigital pressure ulcers, ulcers on the dorsum of a toe, or ulcers on the medial side of the head of the first metatarsal in a hallux valgus. with these stand deviations, poorly fitting footwear will be the direct cause of the ulcer.