Allergy is a broad topic encompassing common clinical allergic diseases, asthma, and complex immunodeficiencies. In this article, the authors discuss the most common allergic diseases and anaphylaxis and briefly review the current knowledge and management of food allergies, allergic rhinitis, otitis media, sinusitis, chronic cough, atopic dermatitis, urticarial and angioedema, contact dermatitis, allergic ophthalmopathy, drug allergy, latex allergy, and insect sting. Because the prevalence of allergic disorders continues to increase, it is increasingly important for physicians to stay up to date on most recent evidence-based diagnosis and management of allergic disorders.