Allergies & intolerances

The specific IgE test measures the concentration in the blood of IgE-type antibodies directed against a particular allergen. When a person is sensitized to an allergen, their immune system produces specific IgE against that allergen; these antibodies are responsible for allergic reactions (hives, rhinitis, asthma, anaphylaxis).

Historically, the method was called RAST (Radio Allergo Sorbent Test) because the first version used radioactive labeling. Today, modern methods (CAP-FEIA, ImmunoCAP, chemiluminescence) have replaced RAST, but the name is still in popular use. At Aclimu we use chemiluminescence and enzyme immunoassay (ELISA) techniques, which are more sensitive and specific than classic RAST.

Specific IgE testing is an alternative to the skin test (prick test) that allergists perform in their office. Its advantages: it is done with a single blood draw, it does not require stopping antihistamines, it carries no risk of reaction and it allows many allergens to be tested at once. It is especially useful in patients with extensive dermatitis, in young children, or when an allergy clinic is not accessible.

This is the most requested group because it covers the most common causes of allergic rhinitis, asthma and allergic conjunctivitis. In most patients with persistent respiratory symptoms, the responsible allergen is in this group.

We test for: house dust mites (Dermatophagoides pteronyssinus and D. farinae, the main ones) and the tropical mite (Blomia tropicalis); environmental fungi (Alternaria, Aspergillus, Cladosporium, Penicillium, Candida, mold panel); pollens and grasses (grass mix, ragweed, ryegrass, Bermuda grass, weed pollen); trees (pine, privet, tree panel); animal dander (cat, dog); feathers; cockroach (Blattella germanica); latex; and environmental dust.

When there is no specific suspicion, testing usually starts with the inhalant IgE screening panel (it measures overall reactivity to a mix of the most common inhalants); if it comes back positive, individual allergens are then tested to identify the specific allergen involved.

We cover the most relevant food allergens: dairy (whole milk and its individual proteins casein, alpha-lactalbumin and beta-lactoglobulin); egg (white, yolk and the individual proteins ovalbumin and ovomucoid —the latter is heat-stable, which is important for assessing whether a person tolerates cooked egg); grains and flours (wheat, corn, oats, gluten, amaranth, soy); nuts (peanut, almond, hazelnut, walnut); fruits (strawberry, orange, kiwi, banana); other foods (tomato, chocolate, beef, fish and shellfish panel).

Specific IgE testing for foods is useful for identifying the cause of acute reactions (hives, anaphylaxis) or when you want to confirm a suspicion. Important: it should not be confused with IgG food intolerance panels, which measure something else (see our intolerances page). IgE-mediated food allergy causes acute symptoms minutes after eating the food; the presence of IgG, on the other hand, usually reflects regular exposure and not necessarily an allergy.

We test specific IgE for bee venom, wasp venom and mosquito. Stings from hymenoptera (bees and wasps) can cause reactions ranging from exaggerated local swelling to severe systemic anaphylaxis. Identifying sensitization allows people with a history of reactions to discuss with their allergist the possibility of specific immunotherapy (allergy shots), a treatment that significantly reduces the risk of anaphylaxis from future stings.

For mosquitoes, the test is used especially in people with exaggerated, persistent or multiple local skin reactions, particularly in areas with a high vector burden.

We cover specific IgE for amoxicillin, ampicillin, oral penicillin, injectable penicillin and cephalosporins. These tests are useful for people with a history of a reaction to beta-lactam antibiotics, to assess the risk of future reactions or to decide whether the workup should be completed with skin tests.

Important: the blood test does not replace a full evaluation by an allergist. A negative specific IgE does not completely rule out an allergy (especially delayed T-cell-mediated reactions, which are not detected with IgE). If your history includes a severe reaction, seeing a specialist is essential.

As part of the inhalant panel, we also offer an overall screening test: the inhalant screening panel, which measures reactivity to a mix of the most common respiratory allergens (dust mites, molds, pollens, animal dander). If it comes back positive, it is worth following up with individual tests to identify the specific allergen responsible. It is available within the IgE Inhalants panel and can be booked for ARS $21,000.

To book your IgE test, on /turnos (our appointments page) you'll see 4 cards (one per category: Inhalants, Foods, Insects, Medications). Click the card you're interested in and the full list of allergens will expand: check the ones you want and they are added to the cart as individual items, each at the listed price. You can combine several in the same blood draw.

Prices are uniform to keep things simple: ARS $21,000 per allergen (inhalants, foods, insects) and $27,000 for antibiotics. The inhalant screening panel is listed within the Inhalants panel.

IgG food intolerance panels measure the levels of specific IgG antibodies against a group of foods. Important: this type of test is NOT equivalent to a food allergy diagnosis (which is based on IgE, as described in the previous sections), nor does it replace a clinical assessment by an allergist or nutritionist. The main allergy societies (EAACI, AAAAI) do not recommend IgG panels for diagnosing food intolerance; they are offered at the request of the patient or the treating physician as complementary information, and the results should always be interpreted with a healthcare professional.

Aclimu offers 4 themed panels of 10 foods each. The panels differ in the foods they include. All of them require 8 hours of fasting beforehand and are processed by chemiluminescence. Price: ARS $320,000 per panel.

Don't cut foods out of your diet (or your children's) because of this result. A high IgG usually means you eat that food often, not that it is harming you. If you have digestive symptoms, see a doctor: there are validated tests for celiac disease, lactose intolerance and other causes.

Celiac disease is an autoimmune disease in which gluten —a protein found in wheat, oats, barley and rye— triggers an immune response that damages the lining of the small intestine. It affects about 1% of the population and has a genetic basis: virtually all celiac patients are HLA DQ2 or DQ8 positive. In Argentina, Law 26.588 recognizes it as a disease of national importance.

At Aclimu we offer two distinct tests. The Biochemical Celiac Profile (Perfil celiaquía bioquímico) includes 3 markers in a single blood draw: anti-transglutaminase IgA (TGA IgA, first-line), total IgA (detects IgA deficiency, which would cause a false negative) and deamidated gliadin peptide IgG (DGP IgG, useful mainly when there is IgA deficiency or in children under 2).

The second test is HLA DQ2 / DQ8, a genetic DNA test that measures predisposition. If both haplotypes are negative, celiac disease is very unlikely —it is a very useful rule-out test—. If they are positive, this indicates predisposition but not a diagnosis (about 30% of the general population carries them). Because it is a DNA test, it is done only once in a lifetime and does not depend on whether the person is eating gluten at the time of the blood draw.

Important note on preparation: for the Biochemical Celiac Profile you need to keep eating gluten as part of your usual diet until the day of the test. Antibodies don't drop overnight: a few days without gluten won't change the result, but a gluten-free diet maintained for months can make them turn negative, and the result loses its diagnostic value — if you haven't eaten gluten for months, talk to your doctor before getting tested. HLA DQ2/DQ8, on the other hand, can be done at any time.