Bonita F. Stanton, MD, Consulting Editor

And then one day, we come across a problem that we believe we have never before encountered—and are not sure we have even read about it. Or, we read about a disorder that we think we have never seen—and realize that we have seen it in one or more of our patients—but did not recognize it.

In this issue of Pediatric Clinics of North America , the authors present in a logical and clear fashion unusual forms of common disorders and uncommon conditions that may mimic more common diseases. All of these conditions are important to contemplate in our differential diagnoses, and the articles help us to organize our thinking in this regard.

I suspect that this issue will provide at least a few “ah-ha!” moments for each of us as we think about patients for whom we have cared over the years, especially those for whom no diagnosis seemed to fit quite right.

This issue will provide fascinating—and helpful—reading for every pediatrician.