RESUMO
BACKGROUND: Tocilizumab, a humanized monoclonal antibody that blocks interleukin-6 receptor, is approved for use in rheumatological diseases. The most frequent adverse events reported are infections. We describe for the first time the occurrence of recurrent aphthous mouth ulcers in two patients on TCZ. PATIENTS AND METHODS: Two patients were treated with TCZ for rheumatological disease. A few weeks after administration of TCZ, they presented with multiple painful mouth ulcers that would not heal until TCZ had been withdrawn. In both cases, the oral ulcers resolved 6 to 7weeks after withdrawal of TCZ and readministration of the drug led to recurrence of oral ulcers within 10days in both patients. DISCUSSION: We describe for the first time the occurrence of aphthous mouth ulcers induced by TCZ. The causative role of TCZ was established by positive rechallenge. These cases were similar to a recently reported case of multiple intestinal aphthous ulcers occurring during TCZ treatment. Such mucosal side effects may be explained by similar inflammatory mechanisms but appear paradoxical because TCZ inhibits a pro-inflammatory cytokine, interleukin 6. TCZ treatment can be maintained if necessary, in combination with colchicine, as reported for one of our patients.
