Anetoderma is characterized by circumscribed areas of flaccid skin due to the loss of elastic tissue in the dermis. It may be primary or secondary to various dermatoses. The primary form has been reported in association with autoimmune diseases and recently with antiphospholipid antibodies. Its etiology remains unknown.

To analyze clinical and laboratory data from a series of patients with anetoderma referred in our university reference center for connective tissue disorders.

All the consecutive patients with histologically confirmed anetoderma followed in our clinic from 1996 to 2001 were enrolled in this study. Laboratory investigations included the screening for prothrombotic abnormalities and classical immunological investigations for systemic lupus erythematosus. Clinical and laboratory data were analyzed retrospectively.

Anetoderma was primary in 9 cases and secondary to lupus profundus in 2 cases. Prothrombotic abnormalities were detected in 10 patients (9/9 with primary and 1/2 with secondary anetoderma). Antiphospholipid antibodies were detected in 9 patients. Only 4 patients fulfilled criteria for definite antiphospholipid syndrome which was primary for 3 and associated with systemic lupus erythematosus in the other.

Patients with anetoderma should be evaluated for the possible presence of a prothrombotic state and warned of its potential risks when present..