Cystic fibrosis (CF) is an autosomal recessive disease resulting from CFTR gene mutation and leading to defective epithelial chloride channel production. The classic clinical triad includes pulmonary disease, exocrine pancreatic insufficiency, and abnormally high sweat electrolyte concentrations. Rarely, patients may present with protein-energy malnutrition (PEM) characterized by edema, anemia, and hypoproteinemia. In this case report, Wenk et al describe a 3-month-old infant with dermatitis heralding the onset of PEM and the diagnosis of CF. Zinc, essential fatty acid, and protein deficiencies may contribute to the development of this eruption, and CF should be considered in the differential diagnosis for any infant presenting with an eruption and other signs of malnutrition.