Semana 14 Nutrición 31/10/22
Introduction to Food Allergies
The speaker introduces the concept of food allergies, discussing hypersensitivity reactions and various immunological mechanisms that can trigger these responses.
Understanding Food Allergies
- Food allergies can result from ingestion, contact, or inhalation of allergenic substances.
- An example is provided where inhaling peach fuzz triggered an allergic reaction in an individual allergic to peaches.
- Food allergies encompass a range of symptoms from mild reactions like sneezing and hives to severe conditions like angioedema and anaphylactic shock.
Definitions and Mechanisms of Food Allergies
The discussion delves into key definitions related to food allergies, including allergens, sensitization, and immunoglobulin E (IgE) responses.
Key Definitions
- Allergen: Components in food, typically proteins, recognized by the immune system triggering a response.
- Sensitization: Initial exposure leading to specific IgE production without immediate symptoms.
- Immunoglobulin E (IgE): Specific antibody produced upon allergen exposure causing subsequent allergic reactions.
Differentiating Food Allergy and Intolerance
Distinguishing between food allergy and intolerance based on immune system involvement and symptomatology.
Differentiation Points
- Food Allergy: Involves positive symptoms along with positive laboratory findings indicative of an immune response.
- Adverse Drug Reactions: Classified as toxic or non-toxic; food allergies are non-toxic reactions occurring in susceptible individuals.
Risk Factors for Developing Food Allergies
Exploring factors such as genetics, early introduction of foods, pet exposure, smoking habits, diet composition, and antibiotic use influencing the development of food allergies.
Risk Factors
- Early formula feeding instead of breastfeeding may increase allergy risk in infants.
- Introduction of solid foods before six months may predispose infants to allergies.
Understanding Food Allergies
In this section, the speaker discusses different types of food allergies based on immunoglobulin reactions and their manifestations in patients.
Types of Food Allergies
- Immediate reactions occur when a patient comes into contact with an allergen, leading to rapid symptoms like anaphylaxis or hives.
- Non-IgE mediated allergies involve inflammation mediated by cellular immunity, such as enterocolitis or proctocolitis caused by certain food proteins.
- Mixed reactions involve both IgE and cellular immunity, manifesting later after consuming the food, like eosinophilic esophagitis.
Hygiene Theory
- Lack of early exposure to infectious agents and intestinal microbiota during childhood increases susceptibility to allergic diseases.
- Early exposure to environmental elements like playing in dirt without excessive hygiene measures may reduce allergy susceptibility in children.
Impact of Environment on Allergies
- Children raised in farm environments with animal and soil contact experience fewer allergic issues compared to urban children exposed to chemical cleaning products excessively.
- Overly sterile environments may heighten allergy risk by limiting immune system exposure to infectious agents that could promote immunity development.
Development of Allergic Diseases
This part delves into the concept of atopic march where individuals prone to allergies exhibit symptoms from infancy through adolescence.
Atopic March Progression
- Susceptible individuals may display early symptoms like eczema or seborrheic dermatitis in infancy, progressing to conditions like asthma and rhinitis in adolescence.
- Common allergens causing issues include milk, eggs, fish, shellfish, nuts, peanuts, wheat, and soy which account for most allergic reactions.
Introduction of Foods to Infants
- Careful introduction of allergenic foods is crucial for infants; gradual introduction every few days helps identify potential allergies without overwhelming the system.
- Introducing one new food at a time allows for easier identification if an allergic reaction occurs compared to introducing multiple foods simultaneously.
Cross-Reactivity in Food Allergies
The discussion shifts towards cross-reactivity where antibodies react not only to original allergens but also similar ones causing unexpected responses.
Cross-Reactivity Explanation
- Cross-reactivity involves specific antibodies reacting not just to the primary allergen but also comparable allergens present elsewhere.
Protein Allergy and Cross-Reactions
In this section, the speaker discusses protein allergies and cross-reactions that can occur in individuals.
Protein Allergy Reactions
- Proteins in certain foods can trigger allergic reactions even if the individual is not allergic to that specific food.
- Certain proteins in foods can resemble allergenic proteins, leading to a cross-reaction.
- Examples of cross-reactions:
- Nuts, peanuts, grains like wheat and oats, cow's milk with goat's milk.
- Peanuts with legumes like beans or peas.
Understanding Physiopathology of Allergies
This part delves into the physiopathology of allergies, focusing on IgE-mediated reactions and their effects on the body.
Physiopathology Insights
- Allergic reactions are primarily mediated by IgE antibodies.
- Increased mucus secretion and histamine release lead to intestinal permeability and vasodilation.
- Mast cells and immunoglobulin E play crucial roles in mediating allergic responses.
- Increased mucus secretion, intestinal permeability, vasodilation, and leukocyte recruitment contribute to inflammation.
Clinical Manifestations of Food Allergies
This segment explores the clinical manifestations of food allergies based on factors like food preparation methods and patient characteristics.
Clinical Manifestations
- Severity of symptoms depends on various factors such as:
- Amount of food consumed, preparation method (e.g., fried), age of the patient affecting absorption rate.
- Immediate IgE-mediated reactions show rapid onset post-food ingestion.
- Symptoms may appear within one to two hours after consuming the allergen.
Types of Allergic Reactions
Different types of allergic reactions are discussed based on timing post-consumption and symptom presentation.
Types of Reactions
- Immediate reactions manifest shortly after consuming allergens causing generalized symptoms like anaphylaxis or localized skin issues.
- Cutaneous manifestations include hives, angioedema, contact urticaria among others.
- Delayed non-IgE-mediated reactions occur hours later showing diverse symptoms involving skin, digestive system (e.g., enterocolitis), respiratory system (e.g., asthma).
Allergy Testing and Treatment Overview
In this section, the speaker discusses various methods of allergy testing and treatment, emphasizing the importance of accurate diagnosis and management strategies.
Allergy Testing Methods
- Allergen skin tests are commonly used but lack specificity for diagnosis.
- Oral challenges involve gradually exposing patients to suspected allergens to determine reactions.
- Oral challenges serve as the gold standard for confirming food allergies.
Allergy Treatment Strategies
- The primary treatment is avoiding allergenic foods by reading labels carefully.
- Substituting allergenic foods with nutritionally equivalent alternatives is crucial, especially in children.
Management of Allergic Reactions
This segment focuses on managing allergic reactions effectively through medication and lifestyle adjustments.
Medication for Allergic Reactions
- Antihistamines are used for symptoms like hives, while adrenaline is crucial for anaphylaxis.
- Corticosteroids and intravenous medications may be necessary in severe cases.
Lifestyle Recommendations
- Exclusive breastfeeding for at least six months is ideal, along with probiotics and prebiotics.
- Introducing new foods every three days after six months aids in preventing allergies.
Differentiating Urticaria and Angioedema
Distinguishing between urticaria and angioedema helps in understanding allergic reactions more comprehensively.
Urticaria vs. Angioedema
- Angioedema involves swelling that can obstruct breathing, while urticaria presents as generalized hives.
Introduction to Food Allergies and Intolerances
In this section, the speaker discusses the introduction of food allergies between 4 to 6 years old, the role of antibiotics, family history of diabetes, and differentiating between allergies and intolerances.
Antibiotics and Food Allergies
- Antibiotics play a significant role in the development of food allergies.
- Family history of diabetes can also influence the likelihood of developing food allergies.
- Understanding these factors is crucial in identifying potential food allergies accurately.
Treatment Options for Food Allergies
This part focuses on treatment options for food allergies, including oral challenges and dietary restrictions.
Treatment Strategies
- Oral challenges are essential in diagnosing food allergies effectively.
- The primary treatment approach involves avoiding consumption of allergenic foods.
Understanding Lactose Intolerance
The discussion shifts towards lactose intolerance, distinguishing it from an allergy and explaining its underlying mechanisms.
Lactose Intolerance Clarification
- Lactose intolerance is not an allergic reaction but rather a lack of lactase enzyme leading to digestive issues like diarrhea.
- Patients with lactose intolerance experience osmotic diarrhea due to the absence of lactase enzyme.
Mixed Type Food Allergy Reactions
The final segment touches on mixed-type food allergy reactions as a concluding point.
Mixed-Type Reactions
- Mixed-type reactions involve complex responses to certain foods.