Multiple eruptive dermatofibromas have been described in association with several underlying diseases. A strong association between MEDFs and immune dysregulation appears to exist, with 69% of reported cases of MEDF associated with an underlying disease, 83% of which were related to dysregulated immunity. Systemic lupus erythematosus was the most common underlying disease associated with MEDF, representing 25% of published cases.3 Multiple eruptive dermatofibromas also have been linked to other autoimmune disorders such as myasthenia gravis,4,5 Hashimoto thyroiditis,4 diabetes mellitus,6 Sjögren syndrome,7,8 dermatomyositis,9 and Graves-Basedow disease.10
Multiple eruptive dermatofibromas also have been linked to immunosuppression, including human immunodeficiency virus11; malignancy12,13; and immunosuppressive or immunomodulatory drugs such as corticosteroids,14 cyclophosphamide,5 methotrexate,9 efalizumab,15 and interferon alfa.12 The degree of immunosuppression, however, does not seem to correlate to the number of MEDFs.3 In addition, MEDFs have been reported in pregnancy and a variety of other systemic disorders including atopic dermatitis,1,16,17 hypertriglyceridemia,8 and pulmonary hypertension.18 We report a case of MEDF in a patient with sarcoidosis who was not treated with immunosuppressive medication. A report of sarcoidosis and MEDF was previously published, but the patient had been treated for many years with prednisone.19 Most reports of SLE-associated MEDF occurred in the setting of steroid use.
Although the etiology of dermatofibromas is unclear, the link between MEDFs and altered immunity has led to speculation that dermatofibromas could be a manifestation of defective autoimmune inflammatory regulation. This hypothesis has been supported by the observation that the lesions are often associated with cells that express class II MHC molecules and also bear morphologic similarity to dermal antigen-presenting cells.20 Reports of familial cases of MEDF suggest that there could be a genetic predisposition.1
The association of MEDFs and underlying immune disorders is important for clinicians to know for appropriate evaluation of potential systemic associations, including sarcoidosis. In addition, biopsy should be considered to confirm the diagnosis with large or atypical lesions to exclude other potential diagnoses. Given the protean nature of sarcoidosis, skin biopsy often is indicated to identify whether cutaneous findings are granulomatous sarcoid-related manifestations. The association of MEDFs with sarcoidosis requires further evaluation but might provide keys to understanding the pathophysiology of these lesions.