Case reports and narrative fallacies: the enigma of black swans in dermatology.

Narrative fallacy is a problematic heuristic that leads us to make inaccurate cause-effect relationships. They are a particular issue in case reports because of the limited scope of these papers, the perpetuated biases they proffer and the misperception of 'black swan' events. This article highlights the negative effects of these fallacies in dermatological practice through three case studies: the use of epinephrine with lignocaine at distal sites, the difference between once-daily and twice-daily application of topical steroids, and the effect of sterile gloves for skin surgery on infection rates. Awareness of the biases in case reports and the employment of metacognition may help us to avoid falling victim to narrative fallacies. Given the potential problems with this heuristic, Clinical and Experimental Dermatology (CED) utilizes case reports to further medical education and offer different clinical perspectives, rather than as a driver of medical knowledge.