Allergy The basis of allergy Common symptoms Some

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Allergy • The basis of allergy • Common symptoms • Some common allergens •

Allergy • The basis of allergy • Common symptoms • Some common allergens • Treatments

The basis of allergy • Immunological reaction • Antibody immunoglobulin E or Ig. E

The basis of allergy • Immunological reaction • Antibody immunoglobulin E or Ig. E • B-cells or plasma cells • Allergen • Mast cells • Histamine and cytokines

 • four types of histamine receptors: H 1, H 2, H 3 and

• four types of histamine receptors: H 1, H 2, H 3 and H 4 • H 1 -histamine receptors • smooth muscle, endothelium and central nervous system tissue • mainly responsible for allergic reactions

Effects of histamine release • Decreased blood flow • Increased cell membrane permeability swelling

Effects of histamine release • Decreased blood flow • Increased cell membrane permeability swelling • White blood cells migrate to the inflammation site Inflammation reaction • redness • swelling • pain • heat • itching

Why is there Ig. E? • Ig. E belongs to the immune system’s ”heavy

Why is there Ig. E? • Ig. E belongs to the immune system’s ”heavy machinery” • Original function: attacking parasites, worms, fleas etc. • ”Hygiene hypothesis” • Modern people lead a cleaner life • No longer exposure to parasites and other pathogens • Ig. E attacks harmless antigens • Exposure to pathogens in early childhood may prevent the development of allergies

Some common symptoms • rhinitis = runny nose • airways: asthma • conjunctivitis =

Some common symptoms • rhinitis = runny nose • airways: asthma • conjunctivitis = inflammation of the eyes: redness and itching • skin: rash, hives and itching • angioedema = rapid swelling of the skin, mucosa and submucosal tissues • anaphylaxis = rapid and severe allergic reaction, low blood pressure, shock

Some common allergens • plants: trees, grass, weeds • foods: nuts, egg, wheat •

Some common allergens • plants: trees, grass, weeds • foods: nuts, egg, wheat • animal products: hair and dander • insects: bee venom, dust mite excretion • mold spores • drugs: salicylates, penicillins, sulfonamides, local anaesthetics

Treatment • Chemotherapy • for relieving the symptoms, not for long-term help • antihistamines

Treatment • Chemotherapy • for relieving the symptoms, not for long-term help • antihistamines • cortisone • adrenaline • theophylline • NSAIDs

 • Immunotherapy • long term help • hyposensitization • vaccinate with small amounts

• Immunotherapy • long term help • hyposensitization • vaccinate with small amounts of allergen • progressively larger amounts • injection of anti-Ig. E antibodies • Alternative therapies • herbal medicine • homeopathy • traditional Chinese medicine

Antihistamines • work against histamine • affect the histamine receptors • inhibitors of histamine

Antihistamines • work against histamine • affect the histamine receptors • inhibitors of histamine release; stabilize mast cells • administration • topically: skin, nose and eyes • systemically: intravenously or orally • a big group of drugs

 • H 1 -reseptor antagonists or H 1 -antihistamines • an antagonist is

• H 1 -reseptor antagonists or H 1 -antihistamines • an antagonist is a molecule that binds to the natural molecule’s receptor, blocks it and thus results in opposite effects in the cell • first-generation H 1 -antihistamines • not very receptor specific • have effects on the central nervous system • second-generation H 1 -antihistamines • more receptor specific • cetirizine (Zyrtec®), loratadine • few side-effects, non-sedating

 • Histamine release inhibitors • inhibit the histamine release from mast cells by

• Histamine release inhibitors • inhibit the histamine release from mast cells by stabilizing the cells • mechanism of action is not fully understood • may also prevent cytokine release • used as nasal sprays and eye drops • cromoglicate

Cortisone or hydrocortisone • a stress hormone that supresses the immune system • systemically

Cortisone or hydrocortisone • a stress hormone that supresses the immune system • systemically for anaphylaxis • topically for allergic edema and rash • many mechanisms of action Adrenaline • a stress hormone • supresses the immune system, increases heart rate • especially for treating anaphylactic shock • many mechanisms of action

Theophylline • also known as dimethylxantine • used for treatment of respiratory diseases e.

Theophylline • also known as dimethylxantine • used for treatment of respiratory diseases e. g. asthma • relaxes the bronchial smooth muscle • mechanism of action is not fully understood NSAIDs • used for their anti-inflammatory effects • acetylsalicylic acid, ibuprofen • used for relieving pain

To summarize: • An allergic reaction is an inflammation reaction mediated by Ig. E

To summarize: • An allergic reaction is an inflammation reaction mediated by Ig. E antibodies • Allergies are becoming more and more common • There is a wide variety of allergens and symptoms • Allergies can be treated by drugs, hyposensitization and alternative treatments • The most common drugs are antihistamines, which either block histamine receptors or inhibit histamine release