My simple and short approach to writing abstract for case reports is to organize the abstract of case report in three sub-sections, consisting of 150-200 words:
Introduction, Case Presentation, and Take-away Lesson.
In 1-2 sentences refer to the topic in general and its importance. That’s all!
in 2-3 sentences present the case in brief, the summary of the main signs, symptoms, and laboratory and imaging findings. Then, the author is required to write 1-2 sentences about any treatment measures, follow ups (if applicable), and the final outcome of the case.
Here, at the end of abstract, provide any relevant practical conclusion (for health or treatment policy makers), in 1-2 sentences.