Long-term effect of methotrexate for childhood atopic dermatitis.

Aim: To evaluate methotrexate (MTX) for paediatric atopic dermatitis (AD) while on and post-treatment.

Methods: Medical records of children prescribed MTX for AD between 2011 and 2016 at Starship Children's Hospital, Auckland, New Zealand, were reviewed for demographics, dose and duration of MTX and hospitalisations for AD. In the follow-up by telephone in 2017, parents of the patients reported response on MTX, AD relapses and use of additional systemic treatment and completed a patient-oriented eczema measure (POEM).

Results: Forty-three patients aged 2-16 years were included. Four (9%) had previous systemic treatment, and 14 (33%) were hospitalised (28 admissions). MTX was given at median dose of 0.33 mg/kg (interquartile range (IQR) 0.26-0.40) for a median of 17 months (IQR 7.5-20). After initiating MTX, only six (14%) were hospitalised (nine admissions). Thirty (70%) parents of patients were followed up for a median of 29 months (IQR 14-45) after discontinuing MTX. Five (17%) reported 'no change', 2 (7%) 'slightly better' and 23 (77%) 'a lot better' AD on MTX. Of the 25 who responded to MTX, AD relapsed in 10 (40%) at a median of 24 months post-MTX; only four (16%) restarted MTX. Median POEM at follow-up was 6 (IQR 1-17). Eleven (37%) were clear (POEM 0-2), 11 (37%) had mild to moderate AD (POEM 3-16), and 8 (27%) had severe AD (POEM ≥17).

Conclusions: Although a natural resolution cannot be excluded, MTX for severe AD was effective and well tolerated. Improvement was reported by 83%, and AD hospitalisation reduced by half. At a median of 2 years after discontinuing MTX, one third were clear, and one third had mild to moderate AD, suggesting persistence of benefit post-MTX.