Although the exact cause of this condition is not known, it is an inflammatory disorder characterised by collagen degeneration, combined with a granulomatous response. It always involves the dermis diffusely, and sometimes also involves the deeper fat layer. Commonly, dermal blood vessels are thickened (microangiopathy). It can be precipitated by local trauma, though it often occurs without any injury.
Necrobiosis lipoidica
Cutaneous lupus mucinosis
Acne necrotica
Tuberculosis verrucosa cutis
Granuloma annulare
Vesiculobullous disease
Ichthyosis bullosa of Siemens
Cutaneous amoebiasis