1 Department of Allergy & Immunology, Northwestern University Feinberg School of Medicine, Chicago, Ill. Electronic address: Brian.cheng@northwestern.edu.
2 Department of Dermatology, The George Washington University School of Medicine and Health Sciences, Washington, DC.
3 Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Ill.
4 Department of Pediatrics and Allergy-Immunology, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Ill.