Glossary of Allergy Terms

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

A (an-)
Prefix denoting absence of; lacking, e.g. alactasia is absence or deficiency of the enzyme lactase.

Acarid
A mite or tick.

ACE Inhibitor
Common medication for blood pressure, which might cause urticaria and chronic cough.

Additive
See Food Additive.

Adjuvant
Any substance used in conjunction with another to enhance its activity. Aluminium salts are used as adjuvants in the preparation of DPT vaccines.

Adrenaline
A drug used to treat anaphylaxis. (It is very similar to the hormone called adrenaline that is produced naturally in our bodies and is responsible for feelings of excitement and stimulation). Also known as Epinephrine in the USA.

Aero-Allergen
Allergen that is suspended in the air and breathed into respiratory tract, where it sets up an allergic reaction.

Allergen
Any substance to which a person is allergic (for example, pollen, house dust mite droppings, animal dander, peanuts).

Allergenic
A predisposition to trigger allergies or cause allergic sensitisation.

Allergic Shiners
Darkening of skin around eyes that occurs in allergy sufferers.

Allergy Clinic
Specialist clinic to assess and carry out diagnostic allergy tests on GP referral.

Allergic March
A pattern that evolves as one allergic condition slowly progresses into another as the person grows up.

Alternative Medicine (complementary, fringe medicine)
The various systems of 'healing' including homeopathy, herbal remedies, hypnosis and faith healing, that are not regarded as part of orthodox treatment by the medical profession.

Anaphylactoid
A reaction similar in presentation to anaphylaxis; however, the cause is not IgE-mediated hypersensitivity. Example: Generalized hives due to direct release of histamine from mast cells by morphine.

Anaphylaxis
A severe allergic reaction with swelling, breathing problems and shock.

Anergy
Failure of lymphocytes that have been primed by an antigen to respond on second contact with the antigen

Anosmia
A loss of the sense of smell.

Angioedema
Similar to hives in that swelling of the skin occurs, but angioedema affects the deeper, subcutaneous layer of the skin and the swollen areas are not itchy. It usually affects the face, genitalia, hands & feet.

Antibodies
Proteins that are produced by our immune system in order to protect our body from 'intruders' such as bacteria and viruses. Immunoglobulin E is the antibody involved in allergic reactions.

Antihistamines
Medicines that are used to treat allergic reactions. They work by blocking the effect of histamine. Available as liquids, tablets and nasal sprays.

Anti-allergy Medication
Nose and eye drops, inhalers and capsules that help prevent allergy. Based on chromoglycate, which is derived from a Middle Eastern plant call Khellin.

Anti-inflammatory Medication
Nose sprays, Inhalers and Creams that contain steroids based on Beclomethasone. See Preventers and Corticosteroids.

Aspergillus
A genus of fungi, which can cause infection or allergy of the respiratory system in man (Allergic Bronchopulmonary Aspergillosis).

Asthma
A disease in which the airways (the breathing tubes taking air in and out of the lungs) become inflamed and swollen, making breathing difficult. In many cases it is caused by an allergy.

Atopy
A predisposition to develop allergy, which may remain latent until clinical allergy develops. Diagnosed by having at least 1 positive skin prick test response or personal or first degree family history of asthma, eczema or hay fever.

Atrophy
Wasting away of a normally developed organ or tissue.

Autoimmune disease
One of the growing number of otherwise unrelated disorders now suspected of being caused by the inflammation and destruction of tissues by the body's own antibodies (autoantibodies). These disorders include Systemic Lupus Erythematosus (SLE), rheumatic fever, and several forms of Thyroid dysfunction including Hashimoto's disease.

B

B cell
A type of lymphocyte that produces antibodies in the humoral arm of the immune system.

BCG (Bacille Calmette-Guerin)
A strain of tubercle bacillus that has lost the power to cause tuberculosis but retaining its antigenicity; it is therefore used to prepare a vaccine against the disease.

Benign
Describes a tumour that does not invade or destroy the tissue in which it originates i.e. non-malignant.

Beta-agonist
Drugs used to relax the bronchial airways, but it also increases heart rate and blood pressure. Bronchodilator medications are beta-agonists.

Bronchiole
The small airways that carry air into and out of the lungs. In people with asthma they become inflamed, narrowed, contracted, and sticky with mucus.

Bronchodilator
A medicine based on adrenaline that is used to treat asthma, such as Salbutamol, used in relievers.

Bronchospasm
The sudden, involuntary contraction of the smooth muscle of the bronchi, as occurs in asthma.

Budesonide
A corticosteroid drug used as a nasal spray to treat hay fever or as an inhalant for asthma. It is also administered as a cream or ointment to treat eczema.

C

Casein
A milk protein; casein is precipitated out of milk in acid conditions; it is the principal protein of cheese.

Causal agent
A factor associated with the definitive onset of an illness. An example of a causal agent is the bacteria causing a specific infection. The relationship is more direct than in the case of a risk factor, and in general the specific ill health will only occur if the causal agent is present. Causal agent is often confused with risk factor.

Cell-mediated
An event accomplished with the assistance of certain cells.

Cell-mediated Immunity
An arm of the specific immune system that defends the body by the ability of T cells to regulate antibody production and to kill invading organisms.

Chemosis
Swelling (oedema) of the conjunctiva.

Chemotaxis
Movement of a cell or organism to the stimulus of a gradient of chemical concentration.

Chinese herbal treatment
A form of traditional Chinese medicine that is helpful for some people with eczema.

Coeliac disease
An inflammatory disease of the intestine, possibly caused by a delayed allergic reaction to gluten, a protein found in wheat, rye, barley and oats.

Commensal
An organism that lives in close association with another of a different species without either harming or benefiting it. For example, some microorganisms living in the gut obtain both food and a suitable habitat but neither harm nor benefit man.

Complement
A substance in the blood, consisting of a group of nine different fractions, that aids the body's defences when antibodies combine with invading antigens. Complement is involved in the breaking up (lysis) of foreign cells.

Conjunctivitis
Inflammation of the conjunctiva (the delicate outer lining of the eyeball).

Contact dermatitis
A type of eczema that occurs when the skin reacts to a substance that comes into direct contact with it. The reaction usually takes 24 hours to develop.

Corticosteroid
A steroid medicine that is used to treat or prevent allergic reactions by reducing inflammation. Used in preventer medicines for people with asthma and in creams to treat eczema. Severe cases may need to be treated orally with corticosteroid tablets.

Cross-reactivity
The interaction of an antigen with an antibody formed against a different antigen with which the first antigen shares identical or closely related properties

CT (Computerized Tomography)
A development of diagnostic radiology for the examination of the soft tissues of the body. For example, in the sinuses it can be used to diagnose infection or polyps. The technique involves recording 'slices' of the body with an X-Ray scanner (CT scanner); these records are then integrated by computer to give a cross-sectional image.

Cytotoxic cells
White blood cells, such as cytotoxic T cells, that are able to release potent chemicals to kill infected cells. They can also attack organ transplant

D

Dander
Animal dander is the tiny particles of skin that are shed by animals such as cats and dogs. These are a major cause of allergies such as asthma and eczema. All furry animals shed dander including hamsters, gerbils, guinea pigs, rats, mice, rabbits and horses.

Decongestants
Medicines that help to relieve the blocked nose associated with allergies such as hay fever and perennial allergic rhinitis. Available as tablets and nasal sprays based on Ephedrine. They relieve congestion by causing vascular constriction

Delayed-type hypersensitivity
A type of hypersensitivity that is mediated by T cells, e.g., allergic contact dermatitis. Gell and Coombs Type 1V Reaction

Dennie Line
Crease seen under eyelid in allergy sufferer.

Dermatitis
Another name for eczema which includes Atopic Dermatitis and Contact Dermatitis.

Dermatographism
A red, raised wheal that develops if the skin is firmly stroked. Commonly seen in people with Urticaria.

Dermatophagoides pteronyssius
A type of house dust mite. Most common cause of asthma in the UK & NZ

Dermatophyte
A fungus belonging to any one of the genera (Microsporum, Trichophyton, and Epidermophyton) that can feed on keratin and cause ringworm (tinea)

Dermatoses
Any disease of the skin, particularly one without inflammation

Desensitization
See Immunotherapy.

Diptera
A large group of insects, including mosquitoes, gnats and houseflies, that possess a single pair of wings.

DBPC (Double-blind Placebo-controlled)
Test in which neither the physician nor the patient knows whether a placebo (dummy) is being administered or a drug or specific food is being administered.

DPT
A combined vaccine against diphtheria, whooping cough, and tetanus.

Dust Mites
Microscopic creatures that live off human dead skin and are a common source of allergy.

Dyspnoea
Laboured or difficult breathing.

E

Ecchymosis
A bruise.

Eczema
A group of skin conditions characterised by dry, red, flaky, itchy skin. The most common form of eczema is allergic or Atopic Eczema (also called Infantile Eczema or Atopic Dermatitis).

ELISA
Enzyme-linked Immunoassay, A technique used to detect antigen or antibody.

Emollients
Special moisturisers – available as bath oils, creams and ointments – that are used to help prevent eczema and hydrate the skin. Usually contain Liquid Paraffin, Cetomacrogol and Emulsifying Wax.

Endotoxin
A poison generally harmful to all body tissues contained within certain Gram-negative bacteria and released only when the bacterial cell is broken down or disintegrates. Compare exotoxin.

E-numbers
Method of labeling all food additives in the European Union. For example, E102 is the food colourant Tartrazine.

Eosinophils
White blood cells containing chemical filled granules that when released kill parasites. Also, eosinophils found in the blood or mucous secretions indicates the presence of allergy.

Eu —
A prefix denoting: 1. Good, well or easy 2. Normal E.g. euthyroid – having a thyroid gland that functions normally.

Excoriation
The destruction and removal of the surface of the skin or the covering of an organ by scraping.

F

Farmer's Lung
An occupational lung disease caused by an allergy to fungal spores that grow in inadequately dried stored hay, straw or grain. Also known as Allergic Alveolitis.

Feingold diet
A diet that purports to treat many illnesses by the elimination of artificial food colouring, preservatives and salicylates from the diet. It has been recommended for the treatment of hyperactivity syndrome, but is of unproven value.

Food Additive
Chemical added to food to enhance flavour, colour and prevent spoiling, but which might cause adverse reaction. Example is Monosodium Glutamate (MSG). See E-numbers.

Food Aversion
Fear that a food will cause an adverse reaction.

Food intolerance or food sensitivity
A sensitivity or bad reaction to certain foods that does not involve the immune system so is not an allergy. Examples are Lactose and Caffeine Intolerance.

Food Toxicity
Reaction to a poison contained in a food.

Food Challenge
Test carried out in hospital to identify suspected food allergens by giving traces of food concealed in capsules or broth. Open Food Challenge is when the food is not concealed.

FEV1: Forced Expiratory Volume
The speed with which air is exhaled during the first second in a pulmonary function test.

Functional disease
A condition in which a patient complains of symptoms for which no physical cause can be found. Such a condition is frequently an indication of a psychological disorder. Compare Organic disorder.

FVC Forced Vital Capacity
The amount of air that can be forced from the lungs over 14 to 20 seconds.

G

Gastro esophageal reflux: GER
The backward flow of gastric juices from the stomach into the esophagus.

Gastro-0esophageal reflux disease (GORD)
The syndrome caused by abnormal gastro-oesophageal reflux, which include symptoms of heartburn and regurgitation.

Generic
Denoting a drug name that is not protected by a trademark.

Glue Ear
Low-grade eardrum inflammation associated with fluid in middle ear cavity.

Gluten Sensitivity
See Coeliac Disease.

Grommet
A flanged metal or plastic tube that is inserted in the eardrum in cases of glue ear. It allows air to enter the middle ear, bypassing the patient's non-functioning Eustachian tube.

H

Haemoptysis
The coughing up of blood.

Halitosis
Bad breath.

Hay fever
An allergy caused by breathing in pollen and by pollen getting into the eyes. Affects the delicate lining of the nose and eyes. Also known as seasonal allergic rhinitis.

Helicobacter
A genus of Gram-negative bacteria. The species H. pylori (formerly classified as Campylobacter pylori) is found in the stomach. It is associated with duodenal ulcer.

HEPA filters: High Efficiency particulate air filters
Filters capable of removing 0.3-micron diameter with an efficiency of at least 99.97%.

Histaminase
An enzyme widely distributed in the body, which is responsible for the inactivation of histamine.

Histamine
A natural chemical that is released by Mast Cells in the body initiating an allergic reaction which leads to inflammation in affected parts of the body.

Histidine
An amino acid from which histamine is derived.

Hives
Another name for urticaria.

Homeopathy
A system of medicine based on the theory that 'like cures like'. The patient is treated with extremely small quantities of drugs that are themselves capable of producing symptoms of the particular disease.

House dust mite
A tiny 0.5mm long spider-like insect that inhabits carpets, bedding and soft furnishings. It eats human skin flakes and thrives in humid environments. Their droppings cause allergies such as Asthma, Eczema and Rhinitis.

Humoral immunity
The arm of the specific immune system that protects the body by producing antibodies.

Hypersensitivity
Exaggerated reactions of the immune system. Gell and Coombs described 4 types: Type I, allergy; Type II, cytotoxic reactions (organ transplantation rejection); Type III, immune complex (serum sickness); and Type IV, delayed-type hypersensitivity (contact dermatitis).

Hyperventilation
Breathing at an abnormally rapid rate at rest, this causes a reduction in carbon dioxide concentration in arterial blood, leading to dizziness, tingling (paraesthesia) in the lips, limbs and tightness across the chest. If continued hyperventilation can cause loss of consciousness. This sequence of events occurs in the Hyperventilation Syndrome (HVS), which has been estimated to contribute to 10% of outpatient referrals to hospital.

Hypo-allergenic
A substance which is unlikely to provoke an allergy. Used to describe milk formula, foods medication or creams.

I

Ichthyosis
Any of a group of disorders, usually hereditary, in which there is noninflammatory scaling of the skin.

Idiopathic
Denoting a disease or condition the cause of which is not known or that arise spontaneously.

Idiosyncrasy
An unusual or unexpected sensitivity exhibited by an individual to a particular drug or food.

IgA
An antibody found in tears, saliva, and mucus, it protects the entrances of the body.

IgE
E-class immunoglobulin (antibody). The type of immunoglobin that triggers release of Histamine from Mast Cells and sets off an acute allergic reaction.

IgG
An antibody that reaches peak levels after IgM and sustains the body's defense.

Ileum
The lowest of the three portions of the small intestines.

Immediate hypersensitivity: Allergy
An IgE-mediated response of the immune system. Gell and Coombs Type 1.

Immune
Protected against a particular infection by the presence of specific antibodies against the organisms concerned.

Immune complex
A cluster of interlocking antibodies and antigens.

Immune response
The response of the immune system to antigens. There are two types of immune response produced by two populations of lymphocytes. B-lymphocytes are responsible for humoral immunity, producing free antibodies that circulate in the blood stream; and T-lymphocytes are responsible for cell-mediated immunity.
Immunization
The production of immunity by artificial means. Passive immunity, which is temporary, may be conferred by the injection of an antiserum, but the production of active immunity calls for the use of treated antigens, to stimulate the body to produce its own antibodies: this is the procedure of vaccination (also called inoculation). The material used for immunization (the vaccine) may consist of live bacteria or viruses so treated that they are harmless while remaining antigenic or completely dead organisms or their products (e.g. toxins) chemically or physically altered to produce the same effect.

Immunoglobulin
A type of immune antibody that may be involved in 'policing' the body for foreign bacteria and allergens. Examples are IgE, IgA, IgG an IgM.

Immunosuppression
Suppression of the immune response, usually by disease (e.g. AIDS) or by drugs (e.g. Steroids, Azathioprine, Cyclosporin A).

Immunotherapy
A treatment for allergy to bee and wasp stings and severe hay fever. It involves having a 3-year course of injections of tiny amounts of the allergen. The treatment leads to the person becoming less sensitive to the allergen.

Impetigo
A skin infection due to the Staphylococcus Bacterium, it forms scabs and has a 'honey-crust' appearance.

Incidence rate
A measure of morbidity based on the number of new episodes of illness arising in a population over an estimated period. It can be expressed in terms of sick persons or episodes per 1000 individuals at risk. Compare prevalence rate.

Incubation period (latent period)
The interval between exposure to an infection and the appearance of the first symptoms.

Inflammation
The body's response to injury, which may be acute or chronic. Acute inflammation is the immediate defensive reaction of the tissue to any injury. It involves pain, heat, redness, swelling, and loss of function of the affected part. In certain circumstances healing does not occur and chronic inflammation.
Inhaler
A device that enables people with respiratory complaints, including asthma, to breathe certain medicines in through their mouth, directly into their lungs.

Inhalant Allergen
An allergy provoking protein suspended in the air that we breathe. See Aeroallergen.

Interleukin
Powerful chemicals released by lymphocytes and monocytes that regulate the immune response.

Interleukin
Any of a family of proteins that control some aspects of the immune response. There are 12 interleukins currently characterised; interleukin-2 (IL-2) stimulates T-lymphocytes.

Intervention study
A comparison of the outcome between 2 or more groups of patients that are deliberately subjected to different regimes (usually of treatment but sometimes of a preventative measure, such as vaccination). Wherever possible those entering the trial should be allocated to the respective groups by means of random numbers, and one such group (controls) should have no active treatment ( randomised controlled trial ). Ideally neither the patient nor the person assessing the outcome should be aware of which therapy is allocated to which patient (blind trial), nor should the doctor responsible for the treatment (double-blind trial), and the groups should exchange treatment after a pre-arranged period ( cross-over trial ).

Irritable Bowel Syndrome (IBS)
A common condition, in which recurrent abdominal pain with constipation and/or diarrhoea, continues for years, without any general deterioration in health. There is no detectable structural disease. The cause is unknown, but the condition is often associated with stress or anxiety.

J
K

Keratoconus
A conical cornea.

Keratosis Pilaris
Dry sandpaper-rough skin texture found commonly in allergy sufferers.

L

Latent Allergy
When allergy testing is positive but no clinical allergy has yet developed to that allergen. See Atopy.

Latex
Rubber derivative commonly found in hospitals in surgical gloves, catheters and intravenous drip-sets. May cause severe allergic reactions during operations.

Leukocytes
All white blood cells

Leukotriene Antagonists
New anti-inflammatory oral medication for Asthma.

Lichenification
The thickening of the epidermis layer of the skin, caused by excessive scratching and rubbing. Seen in patients with eczema

Lymphocytes
Small white blood cells that make up the specific immune system — B cells, T cells and natural killer (NK) cells

Long Face Syndrome
Facial Appearance of the chronic nasal allergy sufferer.

Lymphokine
A substance produced by lymphocytes, that has an effect on other cells involved in the immune system. An example is Interleukin 2 (IL-2).

M

Macrophage
Large phagocytic cells found in tissues and in blood vessel walls. They destroy organisms by engulfing them and presenting them to T and B cells; this to activate antibody production

Major determinants
The part of an antigen molecule that is responsible for the specific interaction with an antibody. Penicilloyl is the major determinant of penicillin because it is responsible for 95% of the anaphylaxis that occurs in penicillin allergic individuals

Mast Cells
The cells that release histamine during an allergic reaction after being triggered by an allergen binding to IgE on its surface.

Mildew
Microscopic fungi, the spores of which can cause asthma in some people. Cladosporium and Alternaria spores are most allergenic.

MMR
A combined vaccine against measles, mumps and German measles (rubella).

Monoclonal Antibody
An antibody produced artificially from a cell clone and therefore consisting of a single type of immunoglobulin. Monoclonal antibodies are produced by fusing antibody-forming lymphocytes from mouse spleen with mouse myeloma cells. The resulting hybrid cells multiply rapidly (like cancer cells) and produce the same antibody as their parent lymphocyte.

Monocytes
Large phagocytic white blood cells that turn into macrophages when they enter the tissues.

Morbidity
The state of being diseased. The morbidity rate is the number of cases of a disease found to occur in a stated number of the population, usually given as cases per 100,000 or per million. Annual figures of morbidity rate give the incidence of the disease, which is the number of new cases reported in the year.

Morbilliform
Describing a skin rash resembling that of measles.

Mortality (mortality rate)
The incidence of death in the population in a given period. The annual mortality rate is the number of registered deaths in a year, multiplied by 1000 and divided by the population at the middle of the year.

Munchausen's Syndrome
A mental disorder in which the patient persistently tries to obtain medical treatment, for an illness that is non-existent: it is an extreme form of malingering. In Munchausen's Syndrome by proxy, the patient inflicts harm on others (often children) in order to attract medical attention.

Mycosis
Any disease caused by a fungus including Aspergillosis.

N

Nasal Concha (turbinate bone)
Any of the three thin scroll-like bones that form the sides of the nasal cavity. The superior and middle nasal conchae are part of the ethmoid bone; the inferior nasal conchae are a separate pair of bones.

Nasal Salute
Rubbing of itchy nose due to nasal allergies.

O

Oral Allergy Syndrome
A localised oral allergic reaction to fruit, vegetables and nuts in Hay Fever sufferers.

Otitis
Inflammation of the ear.

Otorhinolaryngology
The study of ear, nose, and throat diseases (i.e. ENT disorders).

P

Pandemic
An epidemic so widely spread that vast numbers of people in different countries are affected.

Paranasal sinuses
The air-filled spaces, lined with mucous membrane, within some of the bones of the skull. They open into the nasal cavity, via the meatuses, and are named according to the bone in which they are situated. They comprise the frontal sinuses and the maxillary sinuses (one pair each), the ethmoid sinuses (consisting of many spaces inside the ethmoid bone), and the two sphenoid sinuses.
Patch test
Skin tests that can show which substances are causing allergic contact dermatitis or eczema. The test patch is usually applied to the skin on the person's back for 48 hours.

Peak Flow Meter
Device to measure lung expiration and used to monitor asthma severity.

Perennial allergic rhinitis
An allergic condition that has similar symptoms to hay fever but occurs all the year round and is confused with a 'permanent' cold.

Phytophotodermatitis
An eruption of large blisters occurring after exposure to light in people who have been in contact with certain plants, such as wild parsnip, to which they are sensitive.

Pityrosporum
A genus of yeast, producing superficial infection of the skin.

Pollen
The male 'seed' of plants (grasses, flowers, trees) that consists of microscopic dust-like particles. Can cause hay fever, conjunctivitis and asthma.

Polyp
A benign growth with ramifications growing in a mucous cavity for e.g. Nasal Polyp.

Pompholyx
Eczema of the palms of the hands and soles of the feet, associated with intense itching.

Prevalence rate
A measure of morbidity based on current sickness in a population, estimated either at a particular time (point prevalence) or over a stated period (period prevalence). It can be expressed either in terms of sick people (persons) or episodes of sickness per 1000 individuals at risk. Compare incidence rate.

Preventers
Medicines (often based on steroids) that are usually breathed in from inhalers by people with asthma. Help to prevent the disease when taken on a regular basis. Also see Corticosteroids and Anti-inflammatory.

Pruritus
Itching.

Pseudo-allergy
Reaction that mimics an allergy and does not involve the immune system.

Purpura
Skin rash resulting from bleeding into the skin from small blood vessels; the individual purple spots of the rash are called petechiae.

Q

R

RAST
Radio AllergoSorbent Test — a blood test to diagnose what causes a particular allergy. It measures the amount of IgEs in the blood, produced in response to certain allergens. The CAP-RAST is a newer version RAST with over 400 different allergen tests available.

Recombinant DNA
DNA that contains genes from different sources that have been combined by the technique of genetic engineering rather than by breeding experiments Genetic engineering is therefore also known as recombinant DNA technology.

Relievers
Medicines based on Salbutamol that are used to treat the symptoms of an asthma attack by dilating the small airways. Also see Bronchodilators.

Retrospective study
A backward-looking review of the characterics of a group of individuals in relation to morbidity, embracing some aspects of cross-sectional and/or case control studies.

Rhinorrhea
A runny nose, usually with thin watery secretion

Rhinolight
Clinically proven phototherapy treatment (rhino light) of allergic rhinitis now exclusively available at Auckland Allergy Clinic

S

Samster's triad
The triad of asthma, aspirin sensitivity and nasal polyps. .

SCID
Severe combined Immune Deficiency.

Sensitisation
Alteration of the responsiveness of the body to the presence of foreign substances. In the development of allergy, an individual becomes sensitised to a particular allergen and reaches a state of hypersensitivity.
Skin prick test
An allergy test that involves putting a small amount of a known allergen on to a scratch in the skin, to see if the body reacts. Used to diagnose allergy to various pollens, house dust mite droppings and pet dander. Fresh food extracts may be used to accurately skin test for food allergy.

Spacer Device
A plastic tube that fits between the inhaler and the mouth to increase the delivery of atomised medication to the lungs.

Spirometer
An instrument used for measuring the volume of air inhaled and exhaled.

Status Asthmaticus
A severe attack of asthma, which often follows a period of poorly controlled asthma.

Steroids
See Corticosteroids.

Subclinical
Describing a disease or condition that is suspected but not sufficiently developed to produce definite signs and symptoms in the patient.

Subcutaneous
Beneath the skin. A subcutaneous injection is given beneath the skin. Subcutaneous tissue is loose connective tissue, often fatty, situated under the dermis.

T

Tachyphylaxis
A falling-off in the effects produced by a drug during continuous use.

T cell
A type of lymphocyte responsible for cell-mediated immunity by regulating B cell production of antibodies and by acting directly to kill antigens.

Terbinafine
An antifungal drug used to treat severe ringworm. Trade name: Lamisil.
Terbutaline
A bronchodilator drug used in the treatment of asthma. Trade name: Bricanyl.
Tinnitus
Any noise (buzzing, ringing, etc) in the ear. There are many causes including wax in the ear.

Trichophyton
Genus of fungi, parasitic to man, that frequently infects the skin, nails, and hair and cause ringworm.

Trigger
Something that can aggravate an allergic reaction but is not necessarily the actual cause of the allergy. Examples are viruses, exercise, cigarette smoke and cold air.

Tryptase
Enzyme released in acute allergic reactions and during anaphylaxis, which can be measured on a blood test to confirm that an allergic reaction has definitely occurred.

Turbinate
Delicate inner lining of the nasal passage that swells with nasal allergy and blocks nose.

U

Urticaria
A condition characterised by an itchy, bumpy rash. Often caused by an allergy. Also called hives or nettle rash.

V

Vaccination
A means of producing immunity to a disease by using a vaccine, or special preparation of antigenic materia, to stimulate the formation of appropriate antibodies.

Vasomotor Rhinitis
Anon allergic rhinitis caused by changes in temperature, strong odours, or smoke.

Venom
A toxic substance secreted by an insect or a snake.

Vital Capacity
The maximum volume of air that a person can exhale after maximum inhalation. It is usually measured on an instrument called a spirometer.

W

Weal
A raised bump on the skin that indicates an allergy in a skin prick test. Also seen on the skin as Urticaria.

Wet wrapping
A treatment for eczema that involves applying emollients and corticosteroid creams to the affected parts of the body and then wrapping the body in wet bandages.

X

Xeroderma
A mild form of the hereditary disorder, ichthyosis in which the skin is dry and scaly.

Xerosis
Abnormal dryness of the conjunctiva, the skin or mucous membrane.


Y
Z