Paediatric drug allergy clinic - London.

The story is familiar. A young child develops a viral illness. A GP prescribes amoxicillin. Two or three days in, a rash appears. The antibiotic is stopped, "penicillin allergic" is written in the notes, and the family carries that label for the rest of the child's life.

In most of those cases the rash was viral, not drug-related. Viral exanthems and drug reactions look strikingly similar, and when the two happen at the same time the antibiotic usually gets the blame. Once the label is on the record it tends to stay there, following the child into every future GP surgery, dentist, hospital admission and operation.

The consequences add up quietly. Children carrying a penicillin allergy label are given broader-spectrum antibiotics, which work less well for common infections, cost more, and drive antibiotic resistance. Before surgery they get second-line prophylaxis. Their infection outcomes are measurably worse. And when they reach adulthood, they inherit all of that with no memory of what happened when they were three.

De-labelling in childhood is now the standard of care where the original reaction was mild and non-severe. A short, structured clinic assessment can lift a label that would otherwise sit on the records for seventy years.

The first appointment is a paediatric allergist consultation, usually 45 minutes to an hour. The clinician walks through the original episode in detail: when the antibiotic was started, when the rash appeared, what it looked like, whether it itched, whether there was any swelling, wheeze or gut upset, whether the child was already unwell with a fever or cold, and how quickly the rash faded once the drug was stopped. Old photos, if you have them, are genuinely useful.

That history feeds into a risk score. BSACI 2023 paediatric guidance separates children into low, moderate and higher-risk groups. The low-risk group is large: mild delayed rash, no swelling or breathing symptoms, well now, more than 12 months since the reaction. For those children, skin testing is rarely required, and the clinic can move straight to a supervised oral challenge.

Where the story is less clear, or the reaction was more concerning, the clinic steps up to skin testing before any challenge. Nothing is rushed and nothing is done without explaining it to the child in age-appropriate terms first.

BSACI 2023 paediatric guidance recommends a direct 3-day amoxicillin oral challenge as the first-line pathway for low-risk children over 2 years with a history of a mild, non-severe rash more than 12 months ago. No skin prick, no intradermal, no bloods first.

On the day, a paediatric allergist reviews the risk assessment one more time. A single graded dose of amoxicillin is given in clinic, with an observation period afterwards. If the observation is clear, the child continues a full 3-day therapeutic course at home. Families are given clear written instructions on what to look for, when to stop, and who to call.

Published series consistently show more than 95% of appropriately selected children pass the challenge. When they do, the label is formally removed, the GP is written to, and the child is free to receive amoxicillin normally for the rest of their life.

Where the original reaction was more severe, more recent, or the story is unclear, the clinic uses a full step-up pathway. That means skin prick testing, followed by intradermal testing, with a delayed intradermal reading at 48 to 72 hours to pick up T-cell mediated reactions that would be missed on immediate reading.

Only once those are negative does the child move to an oral challenge, and in this group the challenge is done in a day-case paediatric unit with a cannula sited, nursing observation and immediate access to anaesthetic and resuscitation support. For a small subset with suspected delayed contact-type reactions, patch testing may be added.

The whole pathway usually spans two or three clinic visits over four to six weeks. It is more involved than the direct-challenge route, but the reassurance at the end is the same: a definitive answer, in writing.

Children with a confirmed NSAID reaction fall into two groups. Selective reactors respond to one drug (usually ibuprofen) but tolerate structurally distinct alternatives. Cross-reactive reactors respond to the whole class through a shared mechanism affecting the COX-1 enzyme.

Working out which group a child sits in matters because it determines what they can safely be given for pain and fever for years to come. The clinic runs a structured pathway: a supervised paracetamol challenge to confirm tolerance, then, where appropriate, a supervised challenge with a structurally distinct NSAID. In children with cross-reactive disease, a COX-2 selective agent may be tolerated and can be tested in the same way.

Every result is written up as a personalised safe-drug list, so the next time the child has a temperature at 3am the family knows exactly what they can reach for.

Once your child has passed the challenge, the clinic writes to your GP with the result, the risk assessment and a clear request to update the allergy field on the surgery record. The private hospital record is updated the same day.

Families are given a written record of exactly what was tested, the dose used, the observation period and the outcome, in plain language. Keep a copy in your child's health record and take it with you to any new hospital or dentist. If a future clinician ever hesitates, the letter and the challenge documentation are usually enough to resolve it on the spot.

You leave with a confirmed safe drug list for antibiotics, and, if NSAID testing was part of the visit, for pain and fever medications too.