What an Allergy Actually Is
An allergy is an exaggerated immune response to a normally harmless substance โ an allergen. Common allergens include dust mites, pollen, pet dander, mould spores, insect stings, certain medications, latex, and foods such as peanuts, shellfish, or dairy. When you encounter your allergen, the immune system produces immunoglobulin E (IgE) antibodies that trigger the release of histamine and other inflammatory chemicals, causing:
- Sneezing, nasal congestion, post-nasal drip
- Itchy or watery eyes
- Skin rashes, hives, eczema flare-ups
- Wheezing or worsening asthma
- Swelling of the lips, tongue, or throat in severe cases โ rarely, anaphylaxis
Medications like antihistamines and intranasal corticosteroids relieve symptoms but don't address the underlying immune dysfunction. Immunotherapy does โ and is recognised internationally as the only disease-modifying treatment for IgE-mediated allergy.
How Immunotherapy Re-Trains the Immune System
Immunotherapy works by exposing the immune system to controlled, gradually increasing amounts of the specific allergen. Over months, this shifts the immune response away from IgE production and toward immune tolerance:
- Reduces IgE-mediated reactions to the allergen
- Generates allergen-specific regulatory T cells and protective IgG antibodies
- Provides sustained symptom improvement that often persists after treatment ends
Unlike daily antihistamines, immunotherapy aims to change the underlying allergic disease.
Conditions Commonly Treated With Immunotherapy
- Allergic rhinitis โ the most common indication
- Dust mite allergy โ the dominant allergen in Singapore
- Pollen and outdoor allergens
- Pet dander allergy
- Selected cases of allergic asthma linked to a known airborne allergen
Allergy Testing First โ Always
Immunotherapy only works when it's targeted at a confirmed allergen. Before starting, Dr Pang arranges:
- Skin prick testing โ fast, in-clinic, gives results in 15โ20 minutes
- Specific IgE blood testing โ useful when skin testing is contraindicated, or when multiple allergens need confirmation
This makes the therapy personalised, safe, and effective. Read more on allergic rhinitis and dust mite allergy.
The Two Forms of Immunotherapy
Subcutaneous Immunotherapy (SCIT) โ "Allergy Shots"
- Administered as small injections in the clinic
- Doses start very low and gradually increase over a build-up phase of several months
- Maintenance dose given monthly for around 3 years
- Strong evidence base across decades of clinical use
Sublingual Immunotherapy (SLIT) โ "Allergy Tablets/Drops"
- A daily allergen tablet or drops dissolved under the tongue
- First dose taken under supervision in the clinic; subsequent doses self-administered at home
- Needle-free, convenient โ particularly suitable for needle-averse patients and children
- See the dedicated SLIT page for more
Why choose CENTAS for immunotherapy. Dr Pang is an ENT specialist with a focused subspecialty interest in allergy and sinus disease. Before starting immunotherapy, he assesses your nose, sinuses, and airway to ensure treatment is safe and appropriate โ especially for patients with asthma, chronic sinusitis, or structural nasal issues. The clinic handles testing, dose escalation, and monitoring under one roof.
Who Is a Suitable Candidate?
- Persistent symptoms despite optimal medication
- Allergen exposure that cannot reasonably be avoided (dust mites in tropical Singapore is the textbook example)
- Preference for a long-term, disease-modifying approach rather than indefinite daily medication
- Coexisting allergic asthma where airborne allergens drive flares
- Older children, adolescents, and adults โ paediatric SLIT is increasingly used in selected cases
What to Expect During Treatment
Build-up Phase
Doses start very low and gradually increase over several months. Symptoms often begin improving during this phase, though the goal is to safely reach the maintenance dose.
Maintenance Phase
A fixed dose is taken (or injected) regularly for approximately 3 years. Most patients see significant symptom reduction by 6โ12 months and progressively less reliance on antihistamines and nasal sprays. The full course aims for benefit that persists long after the treatment ends.
Safety, Monitoring, and Side Effects
Allergy immunotherapy is safe when administered under specialist supervision. Most side effects are mild:
- SCIT โ mild redness or swelling at the injection site, usually resolving within hours
- SLIT โ temporary mouth tingling, itching, or throat irritation in the first weeks; usually settles spontaneously
- Systemic reactions are rare; serious anaphylaxis is very rare in modern, properly supervised programs
Patients are monitored throughout, particularly during the early build-up phase.
Long-Term Benefits
- Reduced reliance on daily allergy medications
- Sustained improvement that often outlasts treatment
- Lower risk of developing new sensitisations and asthma โ especially in younger patients
- Better sleep, daytime energy, and overall quality of life
- Reduced risk of nasal polyp recurrence after sinus surgery
Frequently Asked Questions
What is allergy immunotherapy?
How long does it take to work?
Is allergy immunotherapy safe?
Do I need allergy testing before treatment?
Can children undergo allergy immunotherapy?
Should I continue allergy medications during treatment?
Related Conditions
Sublingual Immunotherapy (SLIT)
Daily tablets/drops under the tongue โ needle-free immunotherapy.
Allergic Rhinitis
The most common condition treated successfully with immunotherapy.
Dust Mite Allergy
Singapore's dominant indoor allergen โ and a prime target for immunotherapy.
Sinusitis
Treating the underlying allergy reduces sinus recurrence and polyp regrowth.
Book an Appointment
Tired of daily allergy medications? Find out if immunotherapy is right for you.
Dr Pang will review your allergy history, arrange the right tests, and walk through whether SCIT or SLIT fits your case โ with realistic expectations of timeline and outcome.
3 Mount Elizabeth, #16-11, Mt Elizabeth Medical Centre, Singapore 228510