Allergy and immunology

Allergology and immunology, two complementary fields, include the detection, treatment, and prevention of allergic diseases, immune system dysfunction, and immunological aspects of immune-related diseases.

• Allergic bronchial asthma: inflammation affecting the bronchi; triggered by allergens dispersed in the environment, harmless in healthy subjects (e.g. pollen, pet dander).
• Rhinoconjunctivitis: inflammation of the nasal mucosa due to an excessive immunological reaction triggered by allergens to which the patient is sensitized.
• Seasonal allergic rhinitis (or hay fever): allergy caused by a reaction of the immune system to volatile substances (e.g., pollens) present only at certain times of the year.
• Perannual allergic rhinitis: allergy caused by a reaction of the immune system to volatile substances (e.g., house dust) present year-round.
• Allergic contact dermatitis: inflammation of the skin caused by direct contact with allergens; skin changes include, for example, erythema and scaling.
• Food allergies: allergic reaction to a particular food (for example, certain types of nuts, peanuts, shellfish, fish, milk, eggs, wheat, and soy).
• Hymenoptera venom allergies: (e.g., bees, wasps, hornets) can develop at any age and it may take several harmless stings before reactions appear.
• Drug hypersensitivity reactions: immune-mediated reaction toward a drug; symptoms may be mild or severe and include irritation, anaphylaxis, and serum sickness.
• Mastocytosis: abnormal accumulation of mast cells, or cells that are part of our immune system, in the skin and sometimes in other parts of the body.
• Hereditary angioedema: hereditary disease caused by a genetic defect and characterized by the appearance of swelling (edema) of the skin, mucous membranes and internal organs.
• Systemic sclerosis: chronic autoimmune rheumatic disease with degenerative changes and scar sclerosis of skin, joints, internal organs.
• Systemic Lupus Erythematosus (SLE): chronic autoimmune inflammatory disease of connective tissue that can affect joints, kidneys, skin, mucous membranes, and blood vessel walls.
• Sjoegren's syndrome: autoimmune rheumatic disease characterized by excessive dryness of the eyes, mouth and other mucous membranes.
• Systemic large and small vessel vasculitis: inflammatory and necrotic process of blood vessels.
• Rare systemic diseases: adult Still's disease, sarcoidosis, IgG4-related disease, autoimmune myocarditis.
• Immune therapy-induced immune-mediated diseases during neoplasia (Immunocheckpoint inhibitors).
• Autoimmunemyositis: diseases characterized by inflammatory and degenerative changes in muscles (polymyositis, necrotizing immune-mediated myopathy) or skin and muscles (dermatomyositis, Antisynthetase Antibody Syndrome).
• Immunodeficiencies: immunodeficiency disorders are associated with or predispose patients to various complications, including infections, autoimmune diseases, lymphomas, and other cancers. Primary immunodeficiencies are genetically determined and may be hereditary; secondary immunodeficiencies are acquired and found to be much more common. Immune system deficiency-related diseases typical of adulthood include IgA deficiency, common variable immunodeficiency, Good's syndrome, and forms secondary to immunosuppressive treatment, chemotherapy, or HIV infection.

What is allergy

In Switzerland, more than 20% of the population suffers from allergies; the resulting discomfort and suffering, especially in young individuals, has a major impact on quality of life.
"Allergy" refers to an overreaction of the body to foreign substances that are harmless in themselves. These substances-almost always proteins from, for example, pollens, dust mites, animals, food or drugs-are called "allergens"; when a predisposed person comes into contact with the allergen, either by inhaling or ingesting it, the immune system triggers a defensive reaction that induces symptoms.

What is immunology

Immunology deals with the immune system and its malfunctions. Its dysfunctions are responsible for morbid pictures characterized by pathological reactions against the body's own constituents. The resulting spectrum of autoimmune diseases encompasses more than 50 nosological entities. Deficiencies in the immune system, among other manifestations, make affected persons more susceptible to infections by common as well as opportunistic germs.

First visit

Medical examination and evaluation in which the specialist gathers information about the patient, particularly on:

• existence of close relatives with allergies since, in such cases, the probability of allergy is much higher;
• frequency and duration with which allergic reactions occur;
• age of the person at the time the allergic reactions started to occur;
• existence of any trigger (e.g., physical activity, exposure to pollen, animals, or dust) of the allergic reaction;
• any past treatments performed for the allergy and, if so, how he or she responded.

Diagnosis

To make the diagnosis, the doctor may perform blood and/or skin tests:

• blood tests: to detect a type of leukocytes called "eosinophils," which are present in all people but generally produced in greater numbers when an allergic reaction occurs;
• skin tests: to identify specific allergens; there are, for example, the patch test, used to identify skin allergies to, for example, nickel; the prick test, used to detect food and respiratory allergies; and the intradermal test, which is more reliable in detecting a reaction to an allergen;
• allergen-specific tests for measuring serum IgE concentration: blood test, used when skin testing is not possible, for example, in cases of diffuse rash; the test determines whether the IgE in the subject's blood binds to the specific allergen used for the test; if binding occurs, the subject is sensitized to that allergen;
• provocation test: during the test, the subject is directly exposed to the allergen;
• examinations to assess the immune system: assessment of the immune system includes history, objective examination, and various laboratory tests.
  If inflammation is detected from the blood tests, there may be an autoimmune disease, and autonomic antibodies will be sought. If immunodeficiency is suspected with laboratory tests, the humoral and cellular component of immunity will be evaluated. Available tests offered to complement the laboratory include videocapillaroscopy, salivary gland biopsy, and skin biopsy.

Treatments

• Environmental measures: the best approach is to avoid or remove an allergen, for example, stopping taking a medication, keeping pets out of the house, not eating a certain food, using synthetic fiber pillows, etc.
• Antihistamines: these are the drugs most commonly used to relieve allergic symptoms; they block the effects of histamine (which triggers symptoms) but do not block its production; taking them relieves rhinorrhea, eye tearing and itching; however, they do not support breathing if the airway is constricted.
• Corticosteroids: when antihistamines fail to control allergic symptoms, it may be useful to administer corticosteroids; these can be taken, for example, by inhaler, usually to treat asthma.
• Specific immunotherapy (desensitization): usually based on allergy vaccines (injections), may be administered to desensitize a subject to the allergen when certain allergens, especially those found in the air, cannot be avoided and when medications used to treat allergic reactions are ineffective.
• Emergency treatment: severe allergic reactions, such as an anaphylactic reaction, require prompt emergency treatment. Subjects with previous severe allergic reactions should be transported to the emergency department, where they are kept under supervision and treatment can be repeated/corrected if necessary.
• Immunology treatments: disease-modifying immunosuppressive drug therapies, conventional and biologic, for autoimmune diseases and intravenous or subcutaneous supplemental therapy for immunoglobulin deficiencies.