Allergic, hypersensitivity and inflammatory disorders, including but not limited to asthma, allergic rhinitis, mastocytosis, atopic dermatitis and food allergy are exceedingly common disorders. The pathogenesis of these various disorders are being investigated under a number of Laboratory of Allergic Diseases clinical research protocols. This protocol is an evaluation and long term follow-up protocol of such disorders, for the purposes of maintaining a group of patients on which LAD investigators draw for our other various protocols. The patients admitted under this protocol also provide training and experience for members of the NIAID Allergy and Immunology fellowship training programs.