Q: Can we submit a case report about the same patient to journals in different languages and countries?

Based solely on the information you have provided and given that you are aware of doing due diligence, this would not appear to be a problem. There seems to be much to benefit from viewing the same case from different medical perspectives.

All the same, here are some points to keep in mind.

• To be on the safe side, you may check this in a presubmission inquiry to both target journals. You seem to have already planned to do this with the English journal. You may also do this with the Japanese journal. Doing this will save effort and prevent any conflict that may arise later.
• You need to make sure that the content in each paper is distinct enough to not be considered a case of duplicate submission later. There is a likelihood of overlap in some parts, such as when introducing the case and when discussing the symptoms and reactions. So, you need to be careful here.
• Most importantly, this scenario increases the concern over confidentiality, as the patient’s case will now be discussed across two papers. So, you need to make doubly sure that all sensitive information is deidentified. If needed, you may have relevant people from each department, or perhaps even a third neutral party, review the paper for this matter.
• The final consideration is from a publication viewpoint. As multiple people might be involved in the two papers, with some people possibly involved in both papers, you all will need to be extra-cautious that this doesn’t result in a (co)authorship conflict. It would help to discuss author and non-author contribution before starting off, or at least, before submitting each paper. You may go through the International Council of Medical Journal Editors (ICJME) guidelines on authorship here.

You may also refer to the following resources for more insights on publishing case reports.

• Can two papers with same data but different analysis be considered duplicate publication?
• Protecting the identity of enrolled subjects in case reports and clinical trials
• A young researcher's guide to writing a clinical case report

Additionally, you may refer to the CAse REport (CARE) guidelines for writing a case report here.

Hope that helps. All the best for the reports.