Malum perforans is a long-lasting, usually painless ulcer that penetrates deep into or through the skin, usually on the sole of the foot (in which case it may be called malum perforans pedis). It is often a complication in diabetes mellitus and other conditions affecting the nerves. Presentation
These ulcers have punched-out edge and slough in floor, resembling gummatous ulcer. Surrounding area might have loss of sensation. Cause
This condition results from denervation of areas exposed to day-to-day friction of bony prominences. The denervation may be result of any of the following diseases:
Spinal injuries
Leprosy
Peripheral nerve injury
Diabetic neuropathy
Tabes dorsalis
Transverse myelitis
Meningomyelocele
Syringomyelia

Pathophysiology
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, or proximal interphalangeal joint of a hammertoe or on the heel. In non-ambulatory patients, these ulcers are found on buttocks and back of the heel. Diagnosis
Diagnosis is clinical. Sensation is tested using graded monofilament. Treatment
The underlying cause of the neuropathy is first treated. Necrotic portions of the wound are removed and the wound is kept moist at all occasions.
Whilst hearing loss is a common symptom in many diseases of the ear, for example in otosclerosis (abnormal bone growth in the ear), the white, chalky patches on the tympanic membrane are fairly characteristic of tympanosclerosis. Cholesteatoma is similar in appearance but the whiteness is behind the tympanic membrane, rather than inside. Classification
Myringosclerosis refers to a calcification only within the tympanic membrane and is usually less extensive than intratympanic tympanosclerosis, which refers to any other location within the middle ear such as the ossicular chain, middle ear mucosa or, less frequently, the mastoid cavity. Treatment
Hearing aids are a common treatment for hearing loss disorders. A more specific treatment is surgical, involving excision of the sclerotic areas and then further repair of the ossicular chain. There are several techniques, sometimes involving two surgeries; success rates are, however, variable. Damage to the inner ear as a result of surgical procedures is a possible and serious concern, as it can result in forms of sensorineural deafness. Prognosis
In most cases, tympanosclerosis does not cause any recognisable hearing loss up to ten years after the initial disease onset. Sclerotic changes seem to stabilise, but not resolve or dissolve, after 3 years. Epidemiology
Myringosclerosis seems to be more common than tympanosclerosis. Most research has not been conducted upon the general, healthy population, but rather those with otitis media or patients who have had tympanostomy tubes in prior procedures. Of the children studied who had glue ear, and who were treated with tympanostomy tubing, 23-40% of cases had tympanosclerosis.