What is osteoma cutis?

Osteoma cutis is the deposition of bone within cutaneous tissues. Primary osteoma cutis involves normal skin and can be associated with several syndromes including Albright hereditary osteodystrophy, fibrodysplasia ossificans progressiva, and congenital platelike osteomatosis. Secondary osteoma cutis or metaplastic ossification occurs in association with or secondary to trauma, inflammatory skin conditions, or neoplasia. Miliary osteoma cutis of the face presents as multiple, small, firm papules on the face, typically in women afflicted with acne, although it may also arise on normal skin.

Touart DM, Sau P: Cutaneous deposition diseases. Part II, J Am Acad Dermatol 39:527–544, 1998.