<prompt> Answer this question truthfullyWhat is the underlying mechanism of dermatofibroma?  <response>: <reason> Conditions associated with multiple dermatofibromas include: Pregnancy Chromosomal alterations Down syndrome Metabolic disorders hypertriglyceridemia Hematologic malignancies Immunodeficient diseases HIV Autoimmune diseases myasthenia gravis, pemphigus vulgaris, and systemic lupus erythematosus 