Piezogenic Pedal Papule

Excerpt

Shelley and Rawnsley first described piezogenic pedal papules (PPP) in 1968. At that time, they were described as small papular herniations of subcutaneous tissue into the skin of the medial aspect of each heel that occurred only upon standing or upon application of pressure to the sole. They coined the term "piezogenic," meaning "producing pressure;" however, this idiom is used loosely as the pressure triggers the lesions, not the other way around. Subsequently, reports of piezogenic wrist papules and muscle herniation of the lower legs in isolation or coexisting with PPP have been introduced into the literature. These lesions appear to have identical histology to the previously described PPP. Given the diversity of pathology, the term piezogenic papules without specific reference to "pedal" has been used. An infantile variant also exists, and it lacks the piezogenic component.