Allergy Diagnosis and Treatment

Types of Allergies

The most frequently occurring allergic conditions include:

• Allergic rhinitis (hay fever or nasal allergies)
• Allergic asthma
• Allergic conjunctivitis (eye-related allergies)
• Eczema (atopic dermatitis)
• Food allergies
• Hives (urticaria)
• Anaphylaxis (a life-threatening allergic reaction requiring immediate treatment)

Symptoms

Allergies can present in various ways and may affect the eyes, nose, lungs, skin, and gastrointestinal tract. Common signs include:

• Nasal inflammation (rhinitis): Causes sneezing, a runny nose, or congestion.
• Eye inflammation (conjunctivitis): Results in itching, watery, and burning sensation in the eyes.
• Skin rashes: Urticaria (hives) is a red, itchy rash, often accompanied by flushing.
• Tissue swelling (angioedema): Affects the lips, throat, tongue, and eyelids, sometimes starting with a tingling sensation. Severe cases may obstruct breathing and impair speech or swallowing.
• Breathing issues: Symptoms such as wheezing, tightness in the chest, and breathlessness can occur, particularly in severe allergies or anaphylaxis, which can be fatal.
• Cardiovascular collapse: The most severe phase of anaphylaxis, where a drastic drop in blood pressure may lead to unconsciousness or cardiac arrest, requiring immediate resuscitation. This can result in death.

Other possible symptoms are:

• A feeling of impending danger.
• Abdominal pain.
• Nausea or vomiting.
• Heart palpitations (a racing or pounding heartbeat).

Common Allergens

People can develop allergies to a wide range of substances, including:

• House dust mites
• Tree and grass pollens
• Animals, particularly pets like cats and dogs
• Insect venom, such as from bee or wasp stings
• Medications, including antibiotics like penicillin
• Certain foods like nuts and eggs
• Chemicals like latex

The majority of the allergens are proteins, though some, like certain medications, only trigger a reaction after binding to proteins in the body.

Causes

The immune system serves as the body’s defence against foreign invaders, primarily infections. Its role is to identify and respond to these external substances, known as antigens.

Antigens often stimulate an immune reaction by prompting the release of antibodies—protective proteins designed to target specific antigens. These antibodies, called immunoglobulins (IgG, IgM, and IgA), help neutralise foreign particles by binding to their surface; making it easier for immune cells to eliminate them.

In allergic individuals, however, the immune system produces a unique antibody known as immunoglobulin E (IgE) as a response to typically harmless substances like pollen, cat dander or certain foods. Unlike bacteria and other antigens that do not trigger IgE production, these allergens can cause an allergic reaction once IgE is generated and the allergen is recognised.

Diagnosis

Diagnosing allergies starts with a thorough medical history review and physical examination. A family history of allergic conditions is also significant, as many individuals with allergies have close relatives with similar problems. In addition to this, skin testing and occasionally blood tests (measuring specific IgE levels) are used to confirm the diagnosis.

Several factors are important when interpreting allergy test results:

• Environmental allergies (e.g., pets, pollen, dust mites, moulds): Skin prick testing is the most reliable for diagnosing these allergies. Blood tests for allergic antibodies (IgE) may not be as sensitive and can miss some allergens.
• Food allergies: A detailed medical history is crucial in diagnosing food allergies. Skin or blood tests (specific IgE testing) only need to be done if the history strongly suggests a food allergy. Minus this history, these tests are less specific and prone to false positives.
• Food allergy panels: Broad panels for food allergy testing are not recommended due to the high incidence of false positives.
• Drug allergies: Health history is the most critical factor in diagnosing drug allergies. For antibiotics, only penicillin has been validated for skin testing. This is useful in determining if someone is allergic to penicillin or related antibiotics. Blood tests for drug allergies are generally not helpful.

In some cases, like with food or drug allergies, even with comprehensive history review and testing, the diagnosis might remain uncertain. In such situations, a graded challenge test can be conducted. This is considered the “gold standard” for diagnosing allergies, but it must be performed under the supervision of an allergist in a facility equipped to handle severe reactions like anaphylaxis.

Allergy Treatment

Many over-the-counter (OTC) and prescription drugs are available for allergy relief. As a result, it can be overwhelming to figure out where to begin and which treatment is best for you. Our allergists are here to create a personalised plan tailored to your needs and will adjust it as necessary over time.

Common treatment options include:

• Antihistamines: During an allergic reaction, the body releases histamine. Common OTC antihistamines like fexofenadine, loratadine, and cetirizine work by blocking histamine to reduce allergy symptoms.
• Nasal sprays: Similar to antihistamines, nasal sprays can be found over the counter. Some options include cromolyn nasal spray, fluticasone nasal spray, and antihistamine-based nasal sprays.
• Asthma medications: For those with asthma-related allergy symptoms, your healthcare provider may recommend medications such as inhaled bronchodilators, oral bronchodilators, inhaled steroids, or oral anti-leukotrienes to help manage symptoms.
• Immunotherapy: If OTC and prescription medications aren’t effective, allergy shots (immunotherapy) may be recommended. These shots gradually introduce small portions of allergens; and the dosage is slowly increased over time to help the body build tolerance.
• Saline nasal irrigation: A simple OTC option is to use a neti pot. This tool flushes a saline solution through the nasal passages to clear out mucus and allergens on the way.

Conclusion

Allergies are generally a somewhat common occurrence that happens when your immune system wrongly responds to a substance (allergen), triggering an allergic reaction.

It can be incredibly annoying not knowing what’s causing your allergic reactions. Fortunately, we can help you find relief by conducting tests to identify your specific allergens and prescribing medications. We can also refer you to professionals or support groups for additional assistance.

For more information or to address any concerns, book an appointment with us today.