RESUMEN
BACKGROUND: Collagen stimulators such as Ellansé® are soft tissue fillers able to induce nucleogenesis. We describe a case of eruptive foreign body granulomas following injection of Ellansé® that were successfully treated using methotrexate. CASE REPORT: A 47-year-old woman received injections of Ellansé® for the wrinkled aspect of her cheeks. She had previously undergone injections of hyaluronic acid on the nasolabial folds. Nine months after the Ellansé® injections, the patient consulted for the recent appearance of multiple nodules on her face. Histological analysis of one of these nodules confirmed the presence of foreign-body granulomas developed in contact with spherical gaps of a size substantially identical to the Ellansé® vacuoles. Methotrexate 10mg per week for 3 months followed by 20mg per week for 9 months resulted in complete regression of the nodules. DISCUSSION: Ellansé® is composed of two biocompatible and bioabsorbable polymers: carboxymethylcellulose, responsible for immediate volume creation, and polycaprolactone, which promotes collagen synthesis. However, any injected product can cause varying degrees of granulomatous reaction. Hyaluronic acid was previously injected at several other sites on the patient's face. These lesions were not the result of poor injection technique. CONCLUSION: Although collagen stimulators are biocompatible and bioabsorbable substances, the development of foreign-body granulomas, while rare, is still possible. Methotrexate resulted in significant regression of nodules as of the third month of treatment.