Allergy The basis of allergy Common symptoms Some common allergens Treatments

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

four types of histamine receptors: H1, H2, H3 and H4 H1-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 White blood cells migrate to the inflammation site Inflammation reaction redness swelling pain heat itching

Why is there IgE? IgE 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 IgE attacks harmless antigens Exposure to pathogens in early childhood may prevent the development of allergies

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 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 cortisone adrenaline theophylline NSAIDs

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

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

H1-reseptor antagonists or H1-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 H1-antihistamines not very receptor specific have effects on the central nervous system second-generation H1-antihistamines more receptor specific cetirizine (Zyrtec®), loratadine few side-effects, non-sedating

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 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

Theophylline NSAIDs 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 IgE 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