Circumscribed 1- to 2-cm areas of flaccid skin that may be elevated, macular, or depressed.
Often circumscribed sac-like protrusions.
Primary or secondary to a preceding dermatosis in the same location.
Association with antiphospholipid syndrome.
Pathology consists of loss of elastic tissue in the dermis.
The lesions in anetoderma usually occur in young adults between the ages of 15 and 30 years and more often in women than men. Anetoderma is rare, and the incidence is unknown. Several hundred cases have been reported.1-4
The pathogenesis of anetoderma is unknown. The key defect is damage to the dermal elastic fibers. Anetoderma may be considered to be unusual scars, because scars also have decreased elastic tissue. The loss of dermal elastin could be the result of an impaired turnover of elastin caused by either increased destruction or decreased synthesis of elastic fibers.4,5 Recently, a decrease in fibulin protein expression was described, suggesting that not only elastolytic overactivity, but also defective elastic fiber reassembly, may be involved.6 Immunologic mechanisms may also play a role, as it can be associated with various systemic conditions, primarily antiphospholipid antibodies.
All types of anetoderma are characterized by a circumscribed loss of normal skin elasticity. The characteristic lesions are flaccid circumscribed areas of slack skin with the impression of loss of dermal substance forming depressions, wrinkling, or sac-like protrusions (Fig. 70-1). These atrophic, skin-colored, or blue-white lesions are 5 to 30 mm in diameter. The number varies from a few to hundreds. The skin surface can be wrinkled, thinned, and often depigmented, and a central depression may be seen. Coalescence of smaller lesions can give rise to larger herniations. The examining finger sinks without resistance into a distinct pit with sharp borders as if into a hernia ring (buttonhole sign). The protrusion reappears as soon as the pressure from the finger is removed.4
Anetoderma. Primary anetoderma. A, Multiple, sharply defined, depressed lesions that look punched out in the supraclavicular region. B, Soft, sac-like protrusions on the back. When depressed, there is the buttonhole phenomenon. This is the same patient as in A.
The most common sites for these asymptomatic lesions are the chest, back, neck, and upper extremities. They usually develop in young adults, and new lesions often continue to form for many years as the older lesions fail to resolve.
Primary anetoderma occurs when there is no underlying associated skin disease (ie, it arises on clinically normal skin). It is historically subdivided into 2 types: (a) those with preceding inflammatory lesions, mainly erythema (the Jadassohn-Pellizzari type), and (b) those ...