Frequently asked questions

No. Total IgE is the overall amount of IgE antibody in the blood, and it does not indicate which allergen those antibodies are directed against. Raised values can occur in people with allergic disease, but also in parasitic infestations, some infections, skin conditions, autoimmune disease or certain immunodeficiencies.

Values can also be influenced by age, genetic predisposition, environmental exposure and smoking. Sometimes total IgE is raised without any clinically relevant allergic disease being identified.

Not automatically. A positive specific IgE result demonstrates immunological sensitization; on its own it does not confirm allergy. The result has to match the appearance of reproducible symptoms after eating that food.

If the food is eaten and tolerated without reactions, it should not be removed on the basis of the test alone. Unjustified exclusion can lead to nutritional deficiencies, anxiety and a reduced quality of life.

If a food has previously been linked to a severe reaction, it must not be reintroduced at home without the advice of a specialist.

It depends on the testing method.

ImmunoCAP specific IgE blood tests can be carried out during antihistamine treatment. These medicines do not directly change the specific IgE concentration measured in serum.

Skin prick tests can be affected by antihistamines, which reduce the skin’s response to histamine and can produce false negative results. Depending on the substance, treatment may need to be stopped for about 5 to 7 days or even longer. The exact interval differs with the medicine, the dose and how long it has been taken.

Treatment should never be stopped on your own initiative, only on the advice of the specialist, before the consultation.

Yes. There is no universal minimum age for allergy testing when there is a clear indication.

Allergy involves the immune system. It can be IgE-mediated, with symptoms that usually appear quickly, or it can have non-IgE mechanisms. Manifestations can include urticaria, angioedema, vomiting, cough, wheezing, difficulty breathing or anaphylaxis. In some situations even a small amount of allergen can trigger a reaction.

Intolerance is not caused by an allergic mechanism. It usually arises from difficulty digesting or metabolising a substance and often depends on the amount consumed. Lactose intolerance, caused by lactase deficiency, is a typical example: it mainly causes bloating, cramps and diarrhoea, with no IgE mechanism and no risk of anaphylaxis.

Coeliac disease is neither an allergy nor an ordinary intolerance, but an autoimmune disease triggered by gluten.

There is no universally better method. The two investigations both detect IgE sensitization and are complementary.

Skin prick tests

• give results in about 15 to 20 minutes;
• are sensitive, accessible and allow a limited number of allergens to be tested;
• are affected by antihistamines, by the condition of the skin and by the technique used;
• must be performed by trained staff, in a centre equipped to treat any systemic reactions.

ImmunoCAP™ specific IgE blood tests

• give quantitative results, expressed in kUA/L;
• can be carried out during antihistamine treatment;
• are useful in extensive dermatitis, dermographism, reduced skin reactivity or when skin testing cannot be done safely;
• allow both allergen extracts and molecular components to be tested;
• do not expose the patient directly to the allergen;
• provide a complete allergen profile.

Neither test establishes the diagnosis on its own. The choice depends on the clinical situation, and discordant results have to be analysed against the history, the type of extract or component tested and the real exposure.

For total or specific IgE in blood

• you do not need to fast;
• sampling can be done at any time of day;
• antihistamines do not need to be stopped;
• normal hydration is recommended;
• tell the doctor and the laboratory about your treatments, supplements and known conditions.

Preparation for skin testing is different: the doctor has to be told about all medicines being taken, particularly antihistamines, antidepressants with an antihistamine effect and other treatments that can dampen the skin response. These are stopped only on the doctor’s advice.

Reimbursement differs with the type of test, the medical indication, insurance status and the provider’s contract with the health insurance house.

The allergy consultation and certain investigations can be carried out through the Romanian national health insurance system, with a referral and at contracted providers. These investigations include skin prick tests, patch tests and total IgE.

ImmunoCAP™ specific IgE testing of molecular components and the ISAC multiplex test can only be reimbursed in medical institutions that have an allergy department or ward, under day-case admission.

Even where an investigation is eligible, whether it can actually be done may depend on available funding and on the provider’s scheduling. It is therefore worth checking directly with the laboratory or clinic before sampling: whether that exact test is reimbursed, who can issue the referral and what documents are needed.

ImmunoCAP™ technology allows the quantitative measurement of specific IgE antibodies against a wide range of allergen sources. The international portfolio covers more than 500 whole allergens and allergen mixes, as well as more than 100 molecular components. Actual availability can vary between countries and laboratories.

Categories that can be investigated

• inhalant allergens: tree, grass and weed pollens, house dust mites, animal epithelia and dander, moulds and certain insects;
• food allergens: milk, egg, peanut, tree nuts and seeds, cereals, legumes, fruit, vegetables, fish, crustaceans, molluscs, meat and other food sources;
• insect venoms: bee, wasp;
• latex;
• certain drug allergens.

1. Allergy screening

Phadiatop™ and Phadiatop™ Infant show whether there is IgE sensitization to a standardised mix of common inhalant and/or food allergens. The result is global and does not identify the individual allergen responsible.

2. Individual allergens

Specific IgE is measured against a single suspected source, such as mites, ragweed, cat, milk, egg or peanut. The result is reported quantitatively, in kUA/L.

3. Mixes and panels

Allergen mixes give a single collective result. Panels made up of individual tests, by contrast, can report the specific IgE value separately for each allergen included, for example in a respiratory, food or eczema profile.

4. Molecular components

Instead of the whole source, individual proteins are tested, such as Bet v 1, Amb a 1, Der p 1, Der p 2, Ara h 2, Cor a 14, Gal d 1 or Bos d 8. Molecular diagnosis can help distinguish primary sensitization from cross-reactivity and, for certain sources, help assess clinical relevance and the risk profile.

Tests are chosen in a targeted way. The doctor selects allergens according to age, symptoms, exposures, seasonality and the history of reactions. A positive result shows sensitization and must always be correlated with the clinical picture.

An allergic reaction is an emergency when it progresses rapidly, affects breathing or circulation, or involves several organ systems at once. In these situations it may be anaphylaxis, a severe and potentially fatal systemic reaction.

Warning signs include

• difficulty breathing, noisy breathing, wheezing or a feeling of suffocation;
• sudden hoarseness, difficulty speaking or swallowing;
• swelling of the tongue or a sensation of the throat closing;
• severe dizziness, confusion, sudden weakness, fainting or loss of consciousness;
• pallor, cold sweats, a weak pulse or a drop in blood pressure;
• urticaria or angioedema together with significant respiratory, cardiovascular or digestive symptoms;
• repeated vomiting or severe abdominal cramps, particularly after exposure to a known allergen;
• rapid onset of symptoms in two or more systems: skin, breathing, circulation or digestive tract.

Anaphylaxis can occur without urticaria or other skin signs. Bronchospasm, laryngeal involvement or a fall in blood pressure after exposure to a known allergen can be enough to treat the reaction as an emergency.