The rules nobody reads until they have started

Yes, but not straight after a dose. Typical OIT protocols ask for at least two hours without exercise after dosing, and some ask for three, along with avoiding hot showers or baths in that window — exercise and heat both lower the threshold at which a reaction can occur. Protocols also commonly say that if strenuous exercise happened shortly before a scheduled dose, the dose should wait until flushing, sweating and a raised heart rate have settled. For a child with training most evenings, this is the constraint that shapes the whole family schedule. Sublingual protocols generally have no post-dose rest window, which is one reason they suit children in sport.

On oral immunotherapy, a short gap is usually tolerated and a longer one is not. Many protocols allow up to three consecutive missed doses and let you resume at the same dose on the fourth day; beyond that, you call the clinic, and the next dose may need to be given in the office rather than at home. The reason is real: tolerance to the protein can fade, and resuming a full dose after a longer gap carries genuine risk. Sublingual protocols are more forgiving of gaps, but you should still tell whoever supervises you — on Curex that is a text message to your care team.

On oral immunotherapy, dosing is typically held during fever, vomiting, or an acute illness, because being unwell raises the chance of a reaction. That means an ordinary childhood winter can interrupt treatment several times, and each interruption may need a conversation about how to restart. This is one of the less visible reasons multi-year courses get abandoned. Sublingual dosing usually continues through a mild illness.

On a clinic OIT protocol, quite a lot. The build-up phase means frequent in-person up-dosing visits, so the family stays within reach of the clinic for most of a year, and maintenance visits continue after that; a move out of the metro, a long work trip, or a military posting means finding a new program or pausing. Sublingual drops are shipped to wherever you are, dosing needs no clinic, and supervision is a video call. Allergy Associates of La Crosse describes its drops as treatment “you can take wherever you need to be”, and that is the practical difference: the treatment follows the patient rather than the patient following the clinic.

The dose itself is much smaller — food sublingual immunotherapy generally uses no more than about 4 mg of allergen protein per day, held under the tongue for one to two minutes, against the gram-scale doses swallowed on oral immunotherapy. The effect comes through the tissue under the tongue; swallowed, the same dose would be ineffective, which is why the two are never interchangeable. Only the first dose typically needs to happen in a clinical setting, and a pre- or post-dose rest period is generally not required. Smaller dose, fewer reactions, a gentler and generally slower rise in the reaction threshold — and a protocol a family can keep for years.

It is a different tool, and the answer has two halves. Clinic oral immunotherapy raises reaction thresholds faster and further under supervision — roughly 141-fold against 22-fold for sublingual at 12 months in the one head-to-head trial — at the cost of significantly more reactions and dropouts. Over a longer course, sublingual dosing gets most children to a clinically meaningful threshold: in NIH-funded studies at UNC, 67–70% of children on extended peanut SLIT could tolerate 750–800 mg or more of peanut protein, a quarter to a third passed a full 5,000 mg challenge, and in toddlers started at ages 1–4 the median tolerated dose after three years was 4,443 mg against 143 mg on placebo — with no dose in any of the three studies requiring epinephrine. If you can reach a clinic and sustain oral immunotherapy, it moves the threshold faster and further. If you cannot — and 52% of families offered it decline, mostly over time burden — the gentler protocol that gets completed is the one that actually changes the allergy.

There is published work on exactly that. A study in the Journal of Allergy and Clinical Immunology: In Practice examined bypassing the oral immunotherapy build-up phase with an initial period of sublingual immunotherapy for higher-risk food allergy — the build-up being the phase that carries the most reaction risk. That positions the two as sequential rather than rival. It is a conversation to have with an allergist who runs both, not something to arrange yourself.