Introduction: Mesalazine represents a key treatment for Intestinal Bowel Diseases (IBD) and only in rare cases produces cardiac toxicity, presenting mainly as myocarditis, with a not completely known mechanism.
Case report: We report the case of a 25-year-old man in apparent good health status, mild smoker, who accessed our Emergency Department for burning chest pain. In the last month he referred episodes of fever associated with bloody diarrhea and abdominal pain, because of which he underwent colonoscopy, that was not conclusive for IBD. However, therapy with mesalazine was started, with quite alleviation of gastro-intestinal symptoms. After about 2 weeks, the patient accessed our Emergency Department for burning chest pain and fever, with an increase of high-sensitivity cardiac troponin-I at blood tests. The transthoracic echocardiogram evidenced ipocontractility of the inferior and posterior medium left ventricular segments and cardiac magnetic resonance confirmed the suspicion of myocarditis. Antinflammatory and analgesic drugs were started with improvement of patient ‘s condition, but mesalazine was not interrupted. 3 weeks after discharge, he came again to our attention for myocarditis recurrence. Auto-immunity and microbiological laboratory tests, including blood cultures, were negative. The patient was evaluated by a multidisciplinary team, that excluded any other possible cause of myocarditis, except for drug-induced form. Thus, we decided to stop treatment with mesalazine and discharged the patient with lifelong ban of assuming this drug. He didn ‘t show any recurrence of cardiological impairment at our follow-up (8 months) and is in good health status at now.
Discussion: Mesalazine-induced myocarditis is extremely rare. The diagnosis of this condition can be made only by ruling out other causes of myocarditis (in our case through a multidisciplinary team), and considering 2 main features (both present in our patient): symptoms onset within 2-4 weeks after the first drug intake (differently from IBD-related myocarditis) and improvement of patient’s status only thanks to mesalazine interruption. The peculiarity of this case is also represented by the myocarditis recurrence: since the only effective treatment for this condition is stopping mesalazine, in our patient after the first hospitalization myocarditis has recurred because the drug was continued, further supporting our diagnostic suspicion.
