(i) We found 447 cases of AFE described worldwide, including 70 cases of atypical AFE (15.7%). (ii) Based on casuistic reports, we distinguished four subclasses of atypical AFE, which may have clinical implications. (iii) On one hand, it is not certain whether atypical AFE is properly diagnosed (under or overestimation). However, on the other hand, it is known that the term atypical AFE has not been used in epidemiological reports. (4i) Our hypothesis concerning discrepancies in the incidence of AFE between Europe and North America seems justified and confirmed by our findings. However, appropriate prospective research is required as we failed to settle the hypothesis itself.