Oral Methotrexate Treatment of Delayed-Onset Inflammatory Reactions to Dermal Fillers.

Background: In aesthetic practice, delayed-onset (late) inflammatory reactions (DIRs) to dermal fillers are encountered. The treatment of DIRs can be challenging, with a response to established therapies, including oral antibiotics, intralesional and oral steroids, and hyaluronidase injection, occasionally reported as unsatisfactory. Objectives: Evaluate the efficacy of low-dose oral methotrexate (MTX) therapy in treating recalcitrant DIRs. Methods: We retrospectively reviewed cases of recalcitrant DIRs treated with oral MTX. Data collected included individuals' gender and age, medical history, filler type, facial area(s) injected, previous treatments attempted to dissolve the DIR, MTX treatment dosage and duration, and outcome. Adverse events were monitored throughout the treatment. Results: Thirteen females with a mean age of 52.6 years (range, 31-67 years) who developed recalcitrant DIRs to dermal filler injection are included. Eight reactions were triggered by the injection of hyaluronic acid (HA) fillers, 4 by liquid injectable silicone (LIS), and 1 by polymethylmethacrylate (PMMA). The average starting dosage of MTX was 12.1 mg/week (range, 7.5-12.5 mg/week). Patients were treated for 2 to 3 months in most cases. The average follow-up post-MTX therapy was 11.8 months (range, 2-36 months). A complete response to MTX treatment was observed in 10 patients (6 HA and 4 LIS cases), partial response in 1 (HA case), and an unsatisfactory response in 2 (HA and PMMA cases). Treatment was well tolerated. Conclusions: A short course of low-dose oral MTX is a possible treatment for DIRs that have not responded to established therapies. The promising results of this report require validation by powered studies. Level of Evidence 4: