Allergy and Hypersensitivity Reactions

Immune System Diseases

An overreactive or underreactive immune system can lead to a variety of disease conditions. Among the disease conditions associated with impaired immunity are allergies, autoimmune diseases (such as lupus, rheumatoid arthritis, thyroiditis), chronic fatigue syndrome, heart disease and multiple sclerosis.

An allergy is an adverse immune system reaction to a substance that most people find harmless. Allergies can manifest in a variety of ways. Common exmples of an allergic response include, headaches, fatigue, sneezing, watery eyes, stuffy nose or sinuses, and possibly a skin rash that itches following exposure to dust, pollen, dust mites, animal dander, chemicals, foods, and a variety of other materials.

Allergies can cause or contribute to asthma, bronchitis, rheumatoid arthritis, diabetes, ear infections, eczema, hives (urticaria), migraines, chronic fatigue syndrome, gastrointestinal disorders, glaucoma, kidney problems, weight gain, seizures, heart palpitations, depression, and even cerebral palsy and multiple sclerosis among other conditions.

The most common allergic reactions occur immediately after exposure to a certain substance (peanuts, pollen, bee stings or cats). These reactions are typically caused by IgE immunoglobulins, resulting in a runny nose, watery eyes, itching, and skin rashes; more severe reactions include constriction of the bronchial tubes (asthma) and difficulty breathing, or even anaphylactic shock. Delayed allergies can manifest symptoms up to 72 hours after exposure to a triggering substance (typically a food). These can commonly appear as seemingly unrelated illnesses or disorders such as lethargy, attention deficit disorder, fatigue, hyperactivity, itchy skin, mood swings, insomnia, and inflammation of the joints or other tissues. Up to 80 different medical conditions have been associated with IgG food allergy reactions.

• Drug Hypersensitivity
  • Drug Eruptions
    • Toxic Epidermal Necrolysis
    • Erythema Nodosum
    • Serum Sickness
• Environmental Illness
  • Multiple Chemical Sensitivity
  • Sick Building Syndrome
• Delayed Hypersensitivity
  • Allergic Contact Dermatitis
    • Photoallergic Dermatitis
    • Toxicodendron Dermatitis
• Immediate Hypersensitivity
  • Anaphylaxis
  • Allergic Conjunctivitis
  • Atopic Dermatitis
  • Food Hypersensitivity
    • Egg Hypersensitivity
    • Milk Hypersensitivity
    • Nut Hypersensitivity
    • Peanut Hypersensitivity
    • Wheat Hypersensitivity
  • Respiratory Hypersensitivity
    • Extrinsic Allergic Alveolitis
    • Bronchopulmonary Allergic Aspergillosis
    • Asthma
    • Perennial Allergic Rhinitis
    • Seasonal Allergic Rhinitis
  • Urticaria
    • Angioedema
• Immune Complex Diseases
  • Arthus Reaction
  • Serum Sickness
  • Hypersensitivity Vasculitis
    • Schoenlein-Henoch Purpura
    • Cutaneous Allergic Vasculitis
• Latex Hypersensitivity
• Wissler's Syndrome