1 / 11

Food Allergy By Dr Rowan Brown

Food Allergy By Dr Rowan Brown. Problem. Common - (1.6 - 8% of population) Attitude - Medical vs Common Opinion Service Provision - access to specialist opinion + testing Doctor’s Agenda nutritional adequacy of child quality of life parental anxiety.

elisha
Télécharger la présentation

Food Allergy By Dr Rowan Brown

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Food AllergyBy Dr Rowan Brown

  2. Problem • Common - (1.6 - 8% of population) • Attitude - Medical vs Common Opinion • ServiceProvision - access to specialist opinion + testing • Doctor’s Agenda • nutritional adequacy of child • quality of life • parental anxiety

  3. Allergic Types • IgE (Type 1 hypersensitivity) • “Classic” Peanut Allergy • Atopy & anaphylaxis (rapid 20mins -2hrs) • non-IgE (IgG) • examples - coeliac disease • non-specific + delayed symptoms • Intolerance • multiple types - common: lactose intolerance

  4. IgE - mediated allergy

  5. IgE - mediated allergy • Presents with multi-system involvement • urticaria, angio-oedema, rhinitis, cough, eczema vomiting, diarrhoea, abdominal pain, • rapid onset • High association with atopy: ⇒ if present indicates higher likelihood of anaphylaxis • Associated with multiple allergies

  6. IgE - Diagnosis • 4 modalities • History (very important) • IgE-specific titres (CAP-RAST) • Skin prick testing (SPT) • Food Challenges • Tests are sensitive, but have poor specificity, however, in conjunction with positive predictive values and post test probabilities a diagnosis can be made in 70% of cases

  7. IgE Allergy Treatment • Treatment entails elimination of food stuffs • Oral challenge (depending upon natural history of allergy and severity of reaction) • Advice about anaphylaxis + treatment of associated atopy (asthma) • legal vs medical assessment for anaphylaxis prophylaxis • If every child with wheeze treated, (IM adrenaline + training/antihistamine/bronchodilator) the cost per life saved calculated at $20,000,000

  8. Non-IgE Allergy • Onset typically delayed (4-48hrs), and thus poor association with precipitants. • IgG testing not specific with poor concordance - all food stuffs will develop an IgG response. Exceptions to this include coeliac disease with tissue transglutaminase having a high specificity • Management with elimination diets + if necessary food challenges (under medical surveillance if reaction severe) • Unclear association with IBS

  9. Intolerance • Not an immune response • Common - Lactose intolerance. • Inability to hydrolyse lactose to monosaccharide • Results in bloating, diarrhoea, abdominal pain -develops several hours after indigestion • Enterases in gut facilitate hydrolysis. May become functionally inactive post-infection or congenitally missing. It is common post rotavirus infection, but not specific to the young

  10. Cow’s Milk Allergy • Presents with an acute IgE and delayed IgG response. • Typically occurs post breast feeding and introduction of milk - 4-6mths • Mild symptoms may be managed with an elimination diet, with eHF (extensively hydrolysed formula) or AAF (amino acid formula) - in severe cases • Challenge at 9-12mths • Breast feeding thought to be protective, though inconclusive evidence: current ongoing trial “LEAP” designed to answer question

  11. References • Wikipedia “Food Allergy” & “Intolerance” • Arch Dis Child 2007;92:902-908Guidelines for the diagnosis and managment of cow’s milk protein allergy in infants. Yvan Vandenplas etal. • N Engl J Med 2008;359:1252-60 Food Allergy. Gideon Lack • Clin & Exp Imm;55:378-386 Clinical Immnology Review Series: An approach to the patient with allergy in childhood. R Sporik et al

More Related