If you suffered an allergic reaction because a healthcare professional gave you a medication you were known to be allergic to in the UK, you may be able to claim compensation. Every prescriber and dispenser has a duty to check your allergy history. Failure to do so — whether through not reading records, ignoring electronic alerts or failing to ask — can be clinical negligence. Reactions range from minor rashes to fatal anaphylaxis. You normally have three years to claim.
One of the most basic duties in medicine is to check whether a patient is allergic to a drug before prescribing or administering it. NHS electronic prescribing systems flag known allergies automatically. Red wristbands alert nursing staff. Yet drug allergy errors continue to occur, sometimes with devastating consequences. This guide explains how drug allergy claims differ from general prescription error claims. We are an independent information service, not a law firm.
What is a drug allergy claim?
A drug allergy claim arises when a patient suffers a reaction to a medication that should not have been given because their allergy was — or should have been — known to the treating clinician. It is distinct from a general prescription error because the core failing is the failure to check, record or act on allergy information.
How allergy errors happen
| Error | Example |
|---|---|
| Failure to check records | Prescribing penicillin without checking the allergy field documenting a penicillin allergy |
| Overriding alerts | Clicking through an allergy warning in the prescribing system without reading it |
| Failure to ask | Administering a drug without verbally confirming allergy status |
| Recording failure | Patient reports allergy on admission but it is not entered into the system |
| Cross-reactivity ignored | Patient allergic to penicillin given a cephalosporin without assessing risk |
| Handover errors | Allergy information not communicated during shift changes or transfers |
Types of allergic reaction
- Mild — skin rash, urticaria, itching. Usually resolve with antihistamines.
- Moderate — extensive rash, angioedema, gastrointestinal symptoms.
- Anaphylaxis — life-threatening: airway swelling, breathing difficulty, hypotension, cardiac arrest. Requires immediate adrenaline.
- Stevens-Johnson syndrome / toxic epidermal necrolysis — rare but extremely serious skin reactions. Can be fatal.
Proving negligence
You need to show (1) your allergy was documented or disclosed and should have been known, (2) the drug was given anyway, and (3) the reaction caused harm. Evidence includes allergy entries, drug charts, electronic prescribing logs showing overrides, and wristband records. Where the allergy was clearly documented, breach is usually straightforward.
Compensation
General damages depend on severity. Mild rash: modest. Anaphylaxis requiring ICU: significantly more, assessed under JCG 17th edition (2024). Severe skin reactions (SJS/TEN) with lasting scarring: substantial. Fatal anaphylaxis: claims under Fatal Accidents Act 1976. Special damages cover lost earnings, treatment and care.
Time limits
Three years from the reaction or date of knowledge (Limitation Act 1980). For children, three years from age 18. For those lacking mental capacity, no deadline.
Electronic prescribing and allergy alerts
NHS hospitals increasingly use electronic prescribing and medicines administration (EPMA) systems that automatically flag drug allergies when a prescription is entered. When functioning correctly, these systems display a warning if the prescribed drug matches a recorded allergy or belongs to a pharmacological class with known cross-reactivity. However, several failure points can undermine this safety barrier:
- Alert fatigue. When clinicians receive numerous alerts (many of which are minor or clinically irrelevant), they may develop a habit of overriding all alerts without reading them carefully. Studies have shown override rates exceeding 90% for some categories of alert.
- Incomplete allergy records. If the allergy was not entered into the system on admission, or was entered incorrectly (wrong drug name, wrong severity classification), the alert will not fire.
- Paper prescribing bypasses. In some settings, particularly during emergencies, medications may be prescribed on paper charts rather than through the electronic system, bypassing the allergy alert entirely.
- Cross-reactivity gaps. Some systems do not alert for cross-reactivity between related drug classes unless specifically configured to do so.
The duty to check allergies rests with the individual prescriber and administrator — the electronic system is a safety aid, not a substitute for clinical diligence. A clinician cannot rely on the absence of an electronic alert as a defence if they failed to ask the patient about allergies or check the written records.
Reporting and the Yellow Card scheme
Any adverse drug reaction can be reported to the Medicines and Healthcare products Regulatory Agency (MHRA) through the Yellow Card scheme. While this does not provide compensation, it creates an official record of the incident and contributes to national pharmacovigilance. In some cases, Yellow Card reports can reveal patterns of problems with specific drugs or prescribing systems that support a claim. Your solicitor may also obtain data from the trust's own incident reporting system (Datix or equivalent) showing whether similar allergy-override errors have occurred before, which may be relevant to establishing a systemic failing rather than an isolated error.
Getting help
We are not a law firm. For a clinical negligence solicitor, use the Law Society “Find a Solicitor” service or contact AvMA. Most claims run on a no-win-no-fee basis.
Frequently asked questions
What is a drug allergy claim?
It is a clinical negligence claim arising when a healthcare professional gives a medication to which the patient has a documented allergy. The negligence lies in failing to check, record or act on known allergy information.
How is this different from a prescription error?
A prescription error involves the wrong drug, wrong dose or wrong patient. A drug allergy claim specifically involves giving a drug the patient is known to be allergic to. The core failing is the failure to check allergy records.
What reactions can occur?
Reactions range from mild skin rashes to severe anaphylaxis causing airway swelling, cardiovascular collapse and death. Stevens-Johnson syndrome and toxic epidermal necrolysis are rare but extremely serious skin reactions.
Who has a duty to check my allergies?
Every healthcare professional involved in prescribing, dispensing and administering medication: doctors, pharmacists, nurses, dentists and paramedics. NHS electronic prescribing systems flag known allergies automatically.
What if my allergy was not on my records?
If you told a professional about your allergy and they failed to record it, that failure may itself be negligent. If you had a previous documented reaction at the same hospital, failure to carry that forward may also be a breach.
How long do I have to claim?
Generally three years from the allergic reaction or date of knowledge. For children, three years from age 18. For those lacking mental capacity, no deadline while the disability persists.
What compensation could I receive?
Compensation depends on severity. A mild rash attracts modest general damages. Anaphylaxis requiring intensive care attracts substantially more. Fatal reactions give rise to claims under the Fatal Accidents Act 1976.
Should the hospital have had adrenaline available?
Yes. Any facility administering drugs should have emergency anaphylaxis treatment available. Failure to manage anaphylaxis promptly can be a separate ground of negligence.
Get help from official, free sources
- Solicitors Regulation Authority (SRA) — check a solicitor is regulated
- The Law Society — Find a Solicitor — accredited PI specialists
- Citizens Advice — free, impartial guidance on your rights
- GOV.UK — courts, time limits and legal aid information
Related guides: prescription error claims, medical negligence claims, hospital infection claims, fatal accident claims, how compensation works.