<unk>  is more chronic, less acute, less obvious in its presentation, and often more difficult to diagnose than a<unk>  allergy. Symptoms of<unk>  vary greatly, and can be mistaken for the symptoms of a<unk>  allergy. While true allergies are associated with fast-acting immunoglobulin IgE responses, it can be difficult to determine the offending<unk>  causing a<unk>  because the response generally takes place over a prolonged period of time. Thus, the causative agent and the response are separated in time, and may not be obviously related.<unk>  symptoms usually begin about half an hour after eating or drinking the<unk>  in question, but sometimes symptoms may be delayed by up to 48 hours.<unk>  can present with symptoms affecting the skin, respiratory tract, gastrointestinal tract (GIT) either individually or in combination. On the skin may include skin rashes, urticaria (hives), angioedema, dermatitis, and eczema. Respiratory tract symptoms can include nasal congestion, sinusitis, pharyngeal irritations, asthma and an unproductive cough. GIT symptoms include mouth ulcers, abdominal cramp, nausea, gas, intermittent diarrhea, constipation, irritable bowel syndrome (IBS), and may include anaphylaxis.<unk>  has been found associated with irritable bowel syndrome and inflammatory bowel disease, chronic constipation, chronic hepatitis C infection, eczema, NSAID<unk> , respiratory complaints, including asthma, rhinitis and headache, functional dyspepsia, eosinophilic esophagitis and ear, nose and throat (ENT) illnesses.
Food intolerance
Food allergy
Dysphagia
Allergy
Aphagia
Allergies in children
Steatorrhea
Food addiction