Treatment with Methotrexate in Infants and Toddlers with Atopic Dermatitis: A Retrospective Multi-Center Study.

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting up to 20% of children. Methotrexate (MTX) is used off-label as a systemic treatment for AD patients unresponsive to topical therapies, but limited data exist regarding its safety and efficacy in children, especially in those < 4 years old. To further investigate MTX in younger patients, we screened the medical records of three referral centers between 2016 and 2022 and identified 28 infants and toddlers < 4 years old with AD treated with MTX. Mean age upon MTX initiation was 2.7 ± 1.2 years and mean investigator global assessment (IGA) score was 3.78 ± 0.4. Median duration of MTX treatment was five months. Following 12 and 24 weeks of MTX treatment, the response rate was 50% and IGA 0/1 was achieved in 14.2% and 21.4% of patients, respectively. Most treatment cessations were attributed to a lack of efficacy or parental concern. Although adverse events were reported in 57.1% of patients, MTX was discontinued due to such adverse events only in two patients (7.1%). Taken together, MTX demonstrated a high safety profile in AD patients <4 years old. MTX efficacy was moderate and presumably underestimated by parents who opted for premature treatment cessation due to concerns associated with an immunomodulatory drug.