Allergy drops vs allergy shots

Close, with shots holding an edge in the best available comparison. Separate Cochrane reviews found both routes effective for allergic rhinitis versus placebo: 51 trials for shots (Calderón 2007) and 60 trials for sublingual immunotherapy (Radulovic 2010). Head-to-head trials are few and small, so the most rigorous comparison is Dretzke and colleagues’ 2013 indirect comparison in the Journal of Allergy and Clinical Immunology, which found shots produced a somewhat larger reduction in symptom and medication scores, with the difference not conclusive. The AAAAI/ACAAI position is that both are effective and that shots have the longer track record in the US.

Drops carry a lower risk of systemic reactions. Shots are given in a clinic with a 30-minute observation period precisely because systemic reactions, though uncommon, occur at roughly 0.1% of injections in US surveillance, with rare fatalities historically. Sublingual immunotherapy’s reactions are mostly local (mouth itching, mild swelling); anaphylaxis has been reported but is rare, and in Curex’s 2,897-patient cohort adverse events were infrequent and there was no anaphylaxis. Anyone with poorly controlled asthma or a history of anaphylaxis should be evaluated in person before either route.

In-clinic allergen immunotherapy — shots or drops given at a clinic — typically costs $3,000 to $5,000 a year when you include testing, visits and the extract, and in-clinic food allergy programs can exceed $10,000 a year. With good insurance the out-of-pocket for shots may be a copay per visit, often $10–$40, times 25–50 visits in the first year. At-home sublingual drops are almost never billed to insurance; Curex lists $99 a month self-pay, $39 a month with consultations billed to insurance, and financing from $79 a month on some plans. Which is cheaper for you depends almost entirely on your coverage and your distance from a clinic.

Mostly the schedule. Build-up typically means one or two clinic visits a week for three to six months, each with a 30-minute wait afterward, then monthly visits for years. In the largest real-world persistence study, a Dutch pharmacy-dispensing analysis of 6,486 patients, only 18% stayed on immunotherapy for the recommended three years — 23% of those on shots and just 7% of those on drops (Kiel 2013, PMID 23651609). Drops remove the appointments but replace them with a daily habit that also has to be kept, and that study is a warning that the habit is not automatically easier. Curex’s own cohort reported adherence above 90%, which is one reason to read persistence data by service rather than by route.

The customized multi-allergen drops that US providers prescribe are not. Four single-allergen sublingual tablets (grass, ragweed, dust mite) are FDA-approved. The allergenic extracts used to make drops are FDA-licensed products, but putting them under the tongue is off-label use, and FDA has said customized extract mixtures would require a biologics license. Shots use the same licensed extracts by their labelled route. This is a property of the whole drops category, not of any one provider.

When you can keep the schedule and the evidence edge matters to you; when you have insurance that covers immunotherapy with a low copay and a clinic nearby; when you have venom allergy (drops are not used for it); when your allergist wants the closer supervision that in-clinic dosing gives, for example with asthma; and when you prefer not to manage a daily medication at home. Shots are the standard of care in the US for good reasons, and a service that sells drops should say so plainly.

When the shot schedule is the thing that would make you quit — shift work, travel, a rural address, no childcare, needle aversion — or when you are uninsured or on a high-deductible plan and the in-clinic price is out of reach. The route you finish is the one that works. Drops are also the only immunotherapy currently available for food allergy at home.