<prompt> Which immunoglobulin is elevated in a case of chronic allergy?IgAIgMIgEIgG  <response>: Ans. c IgERef: Owen Kuby - Immunology - 8th ed - page 487 Allergy Type I hypersensitivity is always IgE mediated, both in acute and chronic. Eg: Hay fever, Asthma Different examples for allergies Ref: KubyImmune basis for some food allergiesDisorderSymptomsCommon triggerNotes about mechanismIgE mediated acuteHives urticariaWheal and flare swellings triggered by ingestion or skin contactMultiple foods Oral allergyItchiness, swelling of mouthFruits, vegetablesDue to sensitization by inhaled pollens, producing IgE that cross-reacts with food proteinsAsthma, rhinitisRespiratory distressInhalation of aerosolized food proteinsMast-cell mediatedAnaphylaxisRapid, multiorgan inflammation that can result in cardiovascular failurePeanuts, tree nuts, fish, shell-fish, milk, etc. Exercise-induced anaphylaxisAs above, but occurs when one exercises after eating trigger foodsWheat, shellfish, celery may be due to changes in gut absorption associated with exercise IgE and cell mediated chronicAtopic dermatitisRash often in childrenEgg milk, wheat, soy, etc.May be skin T cell mediatedGastrointestina inflammationPain, weight loss, edema, andor obstructionMultiple foodsEosinophil mediatedCell mediated chronicIntestinal inflammation brought about by dietary protein e.g., enterocolitis, proctitisMost often seen in infants: diarrhea, poor growth, andor bloody stoolsCows milk directly or via breast milk, soy, grainsTNF- a mediatedCourtesy: S. H. Sicherer and H. A. Sampson, 2009 Food allergy, Annual Review of Medicine 60: 261-277. 