Pediatric skin diseases are a common presenting complaint to emergency medicine physicians but often pose a significant diagnostic challenge. Skin eruptions that are unusually severe for the diagnosis in question, lasting beyond the typical time of resolution, or not responding to conventional therapy should raise concern of a misdiagnosis. We present the case of a severe rash not responding to conventional atopic dermatitis therapy that led to a diagnosis of transient neonatal zinc deficiency. Clinicians caring for children should be aware of zinc deficiency and its corresponding clinical presentation, because it is readily treatable and may lead to the avoidance of unnecessary treatments and prevention of serious complications.