Allergy

Allergies can develop due to a combination of genetic, immune and environmental factors.

People with a family history of allergies may have a greater tendency to develop allergic conditions. Repeated exposure to substances such as dust, pollen, mould, animal dander, pollution or other allergens can trigger symptoms in susceptible individuals.

An allergy develops when the immune system becomes sensitized to a particular allergen and produces an exaggerated response when exposed to it.

Allergy diagnosis starts with a detailed discussion about the patient's symptoms, medical history and possible triggers. Depending on the symptoms, the doctor may recommend allergy testing.

Common tests include:

• Skin Prick Test
• Total IgE blood test
• Specific IgE blood test
• Allergy blood panel

Test results should be interpreted along with the patient's symptoms and clinical history.

A Skin Prick Test (SPT) is commonly used to identify sensitivity to specific allergens.

Small amounts of selected allergen extracts are placed on the skin, usually on the forearm or back. The skin is then observed for a reaction.

If the patient is sensitized to an allergen, a small raised and itchy area called a wheal may develop.

Skin prick testing can help identify sensitivity to allergens such as:

• Dust mites
• Pollens
• Moulds
• Animal dander
• Other selected allergens

Immunoglobulin E (IgE) is an antibody associated with allergic reactions.

A Total IgE test measures the overall amount of IgE in the blood. A high Total IgE level may occur with allergic conditions but does not identify the specific allergen.

A Specific IgE test can measure the body's immune response to particular allergens.

An allergy blood panel checks for specific IgE antibodies against a selected group of allergens.

Depending on the panel, it may include allergens such as:

• Dust mites
• Pollens
• Moulds
• Animal dander
• Selected foods
• Other environmental allergens

Blood testing may be useful when skin testing is not appropriate or when additional information is required.

Allergy management depends on the type of allergy, severity of symptoms and identified triggers.

Treatment may include:

• Identifying the allergen
• Avoiding known triggers
• Medicines to control symptoms
• Nasal sprays when indicated
• Treatment of associated ENT conditions
• Allergy immunotherapy for selected patients

Once the relevant allergen has been identified, reducing exposure can help control symptoms.

For example, patients with dust-mite sensitivity may benefit from reducing household dust and maintaining good bedroom hygiene.

General measures may include:

• Keep indoor areas clean and well ventilated
• Reduce dust accumulation
• Wash bedding regularly
• Reduce exposure to dust mites
• Avoid cigarette smoke and other irritants
• Minimize exposure to identified allergens
• Follow the environmental precautions recommended by your doctor

Complete avoidance of every possible allergen is not usually necessary. The focus should be on avoiding clinically relevant triggers.

Allergen immunotherapy is a treatment option for selected patients with confirmed allergies.

Unlike medicines that mainly control allergy symptoms, immunotherapy aims to gradually modify the body's response to a specific allergen.

During immunotherapy, carefully controlled amounts of the relevant allergen are administered according to a medically supervised treatment schedule.

Immunotherapy may be considered for selected patients with:

• Allergic rhinitis
• Environmental allergies
• Persistent allergy symptoms
• Symptoms that are difficult to control with routine treatment
• Allergies where avoiding the trigger is difficult

The suitability of immunotherapy depends on the allergen, symptoms, allergy test results, age and overall health.