Normal pressure and pain sensations are essential for protecting the foot from excessive and prolonged pressures over bony prominences. In insensitive foot, such as in diabetic neuropathy, soft tissues are exposed to excessive pressures without knowledge of the individual. In other words, by nerve damage in the feet, the patients get no feedback on the impact of the feet when walking. These ulcers start with callosity under which suppuration takes place. The pus comes out and a hole forms under which the lesion grows deeper. This leads to punched-out, painless ulcers usually under metatarsal heads, tip of toe, proximal interphalangeal joint of a hammertoe or on the heel. In non-ambulatory patients, these ulcers are found on buttocks and back of heel.
Malum perforans
Lichen spinulosus
Lichen aureus
Lichen ruber moniliformis
Herpes gladiatorum
Ichthyosis hystrix
Tinea incognita
Lawsonia inermis