In-Depth Notes on Drugs and Allergy

Drugs and Allergies Overview

• Definition of Allergy:
  • Adverse reaction to harmless material.

Symptoms and Reactions

• Common Symptoms:
  • Cold-like symptoms
  • Geographic tongue

Lymphatic System Issues

• Components of the Lymphatic System:
  • Adenoids: Glands behind the nasal passages.
  • Appendix: Small tube linked to the large intestine.
  • Blood Vessels: Arteries, veins, capillaries for blood flow.
  • Bone Marrow: Soft tissue in bone cavities.
  • Lymph Nodes: Bean-shaped organs throughout the body.
  • Lymphatic Vessels: Channels carrying lymphocytes.
  • Peyer's Patches: Lymphoid tissue in the small intestine.
  • Spleen: Organ located in the abdominal cavity.
  • Thymus: Gland behind the breastbone.
  • Tonsils: Oval masses at the back of the throat.

Pathway of Allergens

• Allergens can enter through:
  • Inhalation
  • Ingestion
  • Skin contact
• IgE Antibodies:
  • Common in allergic reactions like hay fever and asthma.
  • Specific IgE reacts against certain allergens, leading to memory cell production.
  • Re-exposure can trigger allergic reactions with varying symptoms.

Main Types of Allergies (The Big 7)

1. Food Allergies
2. Pet Allergies
3. Drug Allergies
4. Pollen Allergies
5. Latex Allergies
6. Mold Allergies
7. Insect and Pest Allergies

Contact Dermatitis

• Caused by immune reactions,
  • Resulting in blisters at the site of contact.

Common Allergens

• Nickel: Common allergen found in many items, including stainless steel.
• Dust Allergies: Often due to house dust mites and other particles.
• Pet Allergies: Most reactions linked to pet saliva.

Food Allergies vs. Intolerance

• Allergy: Immune system reacts to food.
• Intolerance: Substances in food cause adverse reactions without immune involvement.
• Affect approximately:
  • 4% of adults (food allergies)
  • 30% of adults (food intolerance)

Specific Food Allergies

• Lactose Intolerance: Inability to digest lactose, with lactase supplements available.
• Common Food Allergens: Include wheat (Celiac Disease).
  • Celiac disease affects <1% of the population yet often goes undiagnosed.

Gluten and its Effects

• Concerns: Gluten found in cereal grains (wheat, oats, barley, rye).
• Treatment for Celiac Disease: Gluten-free diets require strict adherence and can be a lifelong commitment.
• Gluten-free foods have seen a rise in popularity, sometimes referred to as a fad.

Allergy and Children

• Children in daycare and those from larger families tend to have fewer allergies due to increased exposure and microbial diversity.
• Reduced levels of infection may correlate with increased allergy rates.

Allergy Mechanisms

• Mast Cells: Display IgE antibodies; when an allergen contacts these IgE molecules, degranulation occurs, releasing histamine.
• Histamine Effects: Produces allergy symptoms like sneezing and itching.

Allergy Management

• Strategies:
  • Avoidance of allergens.
  • Antihistamines (e.g., Benadryl containing Diphenhydramine).
  • Decongestants (e.g., Pseudoephedrine).
  • Immunotherapy: Gradually desensitizes to allergen exposure.

Anaphylaxis

• Severe allergic reactions require immediate medical intervention.
  • EpiPen: Auto-injector for epinephrine is crucial for treating anaphylaxis but can be very expensive.

Drug Pricing Dynamics

• The cost of allergy medications is influenced by development, manufacturing, and market demand rather than just production costs.

Conclusion

• Understanding allergies, their mechanisms, common triggers, and management strategies is vital for prevention and treatment.