[Mesalazine-related interstitial lung disease: an under-diagnosed effect?]

We report the case of a woman treated with adalimumab and mesalazine for a Crohn's disease who presented 9 years after the beginning of the treatments an interstitial lung disease (ILD) discovered by chance during a routine medical examination. Several hypotheses were evocated: progression of the Crohn's disease with a pulmonary involvement then the role of adalimumab was finally suspected. Adalimumab treatment was stopped, but several months later, the pulmonary disease persisted. Six months after the initial medical consult, mesalazine treatment was suspected and stopped. The ILD improved and finally completely resolved with no recurrence after one year. Interstitial lung disease is a rare side effect of mesalazine probably underdiagnosed by physicians especially in patients treated with TNF alpha inhibitors.