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Allergy immunotherapy · London

Sublingual immunotherapy (SLIT) - private in London.

A daily tablet under the tongue for grass, birch or house dust mite allergy - taken at home for 3 years, given by a consultant allergist who observes the first dose safely and reviews you across the course.

A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Indicative pricing

What a private SLIT course costs in London.

Indicative ranges across UK private providers.

In short

£1,500–£3,500 total, daily tablet at home.

Item Indicative range
Initial allergist consultation and testing plan £250–£450
Grazax (grass) - year 1 with reviews £450–£850
Grazax (grass) - years 2 and 3, per year £280–£450
Acarizax (house dust mite) - year 1 with reviews £950–£1,400
Acarizax (house dust mite) - years 2 and 3, per year £550–£850
Total 3-year SLIT course (indicative) £1,500–£3,500

Prices vary by clinic, by the allergist and by which tablet is used. Acarizax is the most expensive licensed option; Grazax and Oralair are less. Reviews across year 1 (typically 1, 3, 6 and 12 months) are included in the year 1 ranges above.

The problem

The right allergen, the right patient, the right clinic.

Antihistamines and nasal steroids only mask symptoms. SLIT is the only disease-modifying treatment for allergic rhinitis and asthma - and it works best when the driver allergen is properly identified first.

  • Is SLIT the right treatment for you?

    Not every allergy patient needs immunotherapy. We look for moderate-severe rhinitis or asthma driven by a single dominant allergen - the sweet spot for SLIT.

  • Which tablet fits the driver allergen?

    Grazax and Oralair for grass, Itulazax for birch, Acarizax and Actair for house dust mite. Component testing helps where the picture is not clean.

  • Started safely, reviewed properly

    The first tablet given under observation, adrenaline auto-injector where indicated, and a review cadence at 1, 3, 6 and 12 months and annually thereafter.

When it helps

Who benefits most from SLIT - and who does not.

The patient patterns we see most, plus the situations where SLIT is deferred or a different immunotherapy fits better.

  • Moderate to severe grass-pollen rhinitis

    Hay fever that spoils May to July every year despite optimal antihistamines, nasal steroid and eye drops - Grazax or Oralair fits.

  • Birch and tree-pollen rhinitis

    Spring rhinitis with birch-driven symptoms, often with oral allergy syndrome to apple, hazelnut or stone fruit - Itulazax fits.

  • House dust mite rhinitis, year-round

    Perennial nasal blockage, morning sneezing and worse symptoms in bed - Acarizax is the licensed option for adults and children 5+.

  • Allergic asthma with rhinitis

    Mild to moderate allergic asthma driven by the same allergen as the rhinitis - SLIT can reduce inhaler use and prevent progression.

  • Symptoms worsening year on year

    A pattern of longer seasons, more medication and reduced response to antihistamines - the point to intervene, not defer.

  • A high medication burden you want to lower

    Daily antihistamine, nasal steroid, eye drops and sometimes a short oral steroid course - SLIT is the only disease-modifying option.

  • Children at risk of progressing to asthma

    A well-selected paediatric course can reduce the odds of developing asthma later, in addition to treating current rhinitis.

  • Red flag: uncontrolled or severe asthma

    SLIT is not started in uncontrolled asthma or during a flare - asthma is optimised first, and severe asthma is a contraindication.

Tablet options

SLIT is a family of licensed tablets - and SCIT sits beside it.

What each licensed option involves - and which fits which patient. Where no licensed tablet exists for the driver allergen, specialist drops or SCIT injections may be the right route.

  • Grazax (timothy grass, single-allergen)

    Licensed for adults and children 5+ with grass-pollen rhinitis. Started 4 months before the season, then daily year-round for 3 years.

  • Oralair (5-grass mix)

    A 5-grass tablet licensed for adults and children 5+. Pre- and co-seasonal dosing from 4 months before the grass season, for 3 seasons.

  • Acarizax (house dust mite)

    Licensed for adults and adolescents 12+ (per NICE) with perennial mite-driven rhinitis or mild-moderate allergic asthma - daily, year-round.

  • Itulazax (birch homologous group)

    Licensed for adults and adolescents 12+ with birch-pollen rhinitis - also covers alder, hazel and oak in the birch homologous group.

  • Actair (paediatric house dust mite)

    A house dust mite SLIT tablet formulation used in selected paediatric patients under specialist supervision.

  • Sublingual drops (specials, private)

    Where no licensed tablet exists for the driver allergen (e.g. some grass, weed or animal dander cases), specialist drop preparations are used off-label.

  • SCIT injections (comparator)

    Subcutaneous immunotherapy - weekly then monthly clinic visits, more effective for polysensitised patients, small anaphylaxis risk.

  • Second-opinion review

    A specialist review of your history, tests and current medications - sometimes the answer is component testing or a different allergen, not another tablet.

Safety and outcomes

What to expect - honestly.

SLIT has the best safety profile of any allergen immunotherapy. About 60 to 70 per cent of well-selected patients get substantial improvement in rhinitis or asthma symptoms and use less medication, with benefit persisting 5 to 7 years after the 3-year course.

  • Mouth itching in the first 1 to 2 weeks

    The commonest side effect - mild oral itching, tingling or lip swelling that settles within 2 weeks in most patients. No dose change usually needed.

  • First dose observed in clinic

    A 30-minute observation after the very first tablet, with an adrenaline auto-injector to hand. Severe reactions are rare but this is the safe way to start.

  • Adrenaline auto-injector where indicated

    Higher-risk patients are prescribed and trained on an auto-injector to carry for the duration of the course - discussed and provided at initiation.

  • Not started during asthma flare

    SLIT is not started in uncontrolled asthma, during a viral infection with wheeze, or in the days after an oral surgical procedure - it is deferred until settled.

  • Severe asthma is a contraindication

    Severe or unstable asthma, active eosinophilic oesophagitis, and significant immunodeficiency are contraindications to SLIT and reviewed at consultation.

  • Daily consistency matters

    A missed day or two is usually fine - a gap of more than 7 days often needs a supervised restart. We give you a written contingency plan.

  • Pregnancy - continue, do not initiate

    SLIT is not initiated during pregnancy. If you become pregnant on a course that is already tolerated, most guidelines support continuing.

  • Cost planning across 3 years

    Insurers vary in how they cover the tablet and the reviews.

  • Red flags after a dose

    Wheeze, widespread hives, throat tightness, faintness or severe swelling - use the auto-injector and call 999. Contact the clinic the same day.

Reading your allergist letter

Your SLIT plan in four parts. Read the last one first.

Whichever tablet you are on, the letter the allergist sends you keeps to the same shape.

A London allergist reviewing a SLIT initiation letter

A quiet reminder

Allergy language is precise and can read coldly - we translate it for you.

If you would like us to talk you through the letter before your review, just ask.

  1. 01 Header

    Allergen, product and start date

    Which allergen (grass, birch, mite, or mix), the tablet name and strength, the observed first-dose date and any pre-seasonal window.

  2. 02 Technique

    Dose schedule and duration

    Daily dosing instructions, hold-under-tongue time, missed-dose rules, planned duration (usually 3 years) and review intervals.

  3. 03 Findings

    Tolerability and asthma control

    How the first two weeks went, any oral or systemic reactions, current asthma control and any medication step-down already achieved.

  4. 04 Impression

    Plan for the next season and review

    Read this first: expected benefit, when to expect it, what to do at the start of the next season, and the date of the next review.

Recognised by major UK insurers

BupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealix

Cover for SLIT varies by insurer and by indication - most fund the consultation and testing; tablet cover across 3 years is variable.

Frequently asked

Everything we get asked about SLIT.

Quick answers on cure, duration, side effects, children, multiple allergies and insurance cover.

  • Is SLIT a cure for allergy?

    SLIT is the only disease-modifying treatment for allergic rhinitis and mild-moderate allergic asthma - it retrains the immune system rather than masking symptoms. It is not called a cure, but 60 to 70 per cent of patients get substantial, long-lasting improvement, with benefit persisting 5 to 7 years after the 3-year course finishes.

  • How long does the course last?

    Three years of daily dosing. Grass and birch tablets can be pre- and co-seasonal, started about 4 months before the season and continued through it, for 3 consecutive seasons. House dust mite tablets are taken daily, year-round, for 3 years. Shorter courses are less effective and less likely to give lasting benefit.

  • What are the common side effects?

    Mild oral itching, tingling and lip or tongue swelling in the first one to two weeks - usually settling without any dose change. Systemic reactions are uncommon and severe anaphylaxis is rare. The first tablet is given in clinic under observation and higher-risk patients carry an adrenaline auto-injector.

  • Can children have SLIT?

    Yes. Grazax and Oralair are licensed for children 5 and over. Acarizax is licensed by the EMA from 5 upwards but NICE recommends it from 12 in the UK - a paediatric allergist will advise. Itulazax is licensed from 12. A well-selected paediatric course can also reduce the risk of progressing to asthma.

  • What if I am allergic to more than one thing?

    Licensed SLIT tablets treat one allergen family at a time - grass, birch or mite. If a patient is polysensitised, component-resolved testing (ISAC or ALEX) helps identify the driver allergen so the tablet is chosen well. Where multiple drivers matter equally, SCIT injections may be a better fit.

  • Does private health insurance cover SLIT?

    Cover varies. Most major UK insurers fund the initial allergist consultation and testing when medically indicated. Some cover the SLIT tablet and reviews across the 3 years, others do not.

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