Clavus

A clavus is a thickening of the skin due to intermittent pressure and frictional forces. These forces result in hyperkeratosis, clinically and histologically. The extensive thickening of the skin may result in chronic pain, particularly in the forefoot; in certain situations, this thickening may result in ulcer formation.Synonyms for clavus include callosity, a hyperkeratotic response to trauma; heloma, or a circumscribed hyperkeratotic lesion that may be hard (i.e., heloma durum) or soft (i.e. heloma molle); and callous, callus, or a diffusely hyperkeratotic lesion. Localized callosities of the soles, which do not resolve, are termed plantar callus, heloma, tyloma, keratoma, or plantar corn.When callosities occur over 1 or more lateral metatarsals, they are termed intractable plantar keratoses.