Methotrexate is only prescribed in atopic dermatitis when azathioprine doesn't work. I have some experience in adult atopic dermatitis but much more experience with azathioprine that is a very useful drug in this disease.
Yes at our hospital in London(Great Ormond Street Hospital) we have used MTX for severe atopic eczema where Azathioprine treatment has failed. I believe there is a protocol we share with the rheumatology team who use it for morphea in children.
I have experience only in adult patients. So I want to share a problem with more expert discussants than me. I know what cautions must be taken in adults when MTX and AZA are used. Are they the same for children or are different? And in this case, what are the main differences?
Atopic dermatitis in a child: If you want to try a immunomodulator in atopic dermatis you can use cyclosporin in low doses because it is much well tolerated than MTX.