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A Guide to Allergens in Healthcare


Allergic reactions can be a potential risk in any setting, but even more so in healthcare due to the many allergens present and the number of individuals accessing these services. If healthcare providers do not manage allergens properly, it can increase the risk of severe allergic reactions, some of which can be fatal.

While most individuals do not react to allergens, allergies are still common and can occur at any age. In fact, more than 1 in 4 people in the UK are affected by allergies at some point. Also, allergy cases are increasing yearly, mainly in children (British Society for Immunology). Therefore, it is a risk that all healthcare providers and professionals should take seriously.

Here, you will cover everything you need to know about allergens in healthcare and how to prevent, reduce and manage the risks.

A Guide to Allergens in Healthcare

Defining allergens in healthcare

Allergens are protein or non-protein substances that can trigger an abnormal immune system response. When an allergic individual comes into contact with an allergen, their immune system perceives it as a threat and overreacts, even though the substance is relatively harmless.

During the immune system response, the body goes into defence mode by suddenly releasing chemicals, such as histamine. These chemicals cause allergy symptoms, which are minor in most cases.

Other individuals may have severe, life-threatening allergic reactions known as anaphylaxis. This systemic overreaction of the immune system can result in life-threatening symptoms, such as breathing complications and shock. An estimated 20 anaphylaxis-related deaths are reported annually in the UK (NICE).

Any substance (trigger) can be an allergen if it can cause an individual to experience an allergic reaction. In healthcare environments, these substances are likely present in foods, medications/drugs, latex products, contrast media/agents and cleaning agents. They can also be in the environment.

A Guide to Allergens in Healthcare

Common allergens in healthcare

The allergens present will depend on the type of healthcare setting and the services provided. To manage and control the risks to patients, staff and visitors, healthcare providers should identify potential allergens and assess the risks. The findings from a risk assessment should form the basis of allergen policies, procedures and protocols.

So, what common allergens would you expect to find in a healthcare environment? There are many types of allergens, but some commonly found in healthcare are foods, medicines/drugs, contrast media/agents, latex and cleaning agents.


Estimates show that more than two million people are living with a diagnosed food allergy in the UK, and it is possible these numbers are much higher (Natasha Allergy Research Foundation (NARF)). Therefore, healthcare professionals may encounter individuals with food allergies at some point.

Even though deaths from allergic reactions to food have declined over the past 20 years, there has been an increase in hospital admissions for food-induced anaphylaxis (Imperial College London).

Patients, staff and visitors are given foods and drinks in most healthcare settings, and individuals could have an allergy to any foods provided on-site. However, the following 14 allergens are the most prevalent and more likely to cause a reaction:

  • Celery (all of the plant, including the root celeriac).
  • Cereals (gluten) (oats, rye and barley).
  • Crustaceans (crab, prawns and lobster).
  • Eggs.
  • Fish.
  • Lupin (flower and seeds).
  • Milk.
  • Molluscs (oysters, snails and mussels).
  • Mustard (liquid, powder and seeds).
  • Peanuts (groundnuts).
  • Tree nuts (almonds, hazelnuts, walnuts etc.).
  • Sesame (seeds).
  • Soybeans.
  • Sulphur dioxide and sulphites.

Food is a common trigger in children, with cow milk being the commonest, single cause of fatal food-induced allergic reactions in those school-aged (The BMJ).

Medicines and drugs

All medicines and drugs can cause side effects but are not always allergy-related. However, 5-10% of people in the UK have a drug allergy (NHS), and drugs are among the first three leading causes of anaphylactic reactions (Allergy UK). Reactions of medicinal products are much more common triggers in older people.

Patients will be given various medicines and drugs in healthcare settings, and healthcare professionals may be involved in dispensing, handling and administering. Patients may also present with drug allergy symptoms. Therefore, there is a risk to patients and healthcare staff.

All medicines and drugs have the potential to cause reactions in individuals, whether they are over-the-counter, prescription or herbal, or given to patients in hospital or other settings. However, some are more likely to be triggers, such as:

  • Antibiotics, e.g. penicillin. Approximately half a million are admitted to NHS hospitals annually because of a diagnostic ‘label’ drug allergy, the most common being due to penicillin (Allergy UK).
  • Chemotherapy drugs.
  • Insulin.
  • Anti-convulsant drugs, e.g. carbamazepine and phenytoin.
  • General and local anaesthetic. Approximately 500 people have serious allergic reactions to anaesthetic drugs annually in the UK; one in every 10,000 procedures (Anaphylaxis UK).
  • Painkillers, e.g. aspirin and non-steroidal anti-inflammatory pain medicines (NSAIDs), such as ibuprofen and naproxen.
  • Vaccines, i.e. some contain egg protein.

Drugs and medicines are taken by mouth, applied to the skin or injected, and these methods can affect allergic reactions. According to Anaphylaxis UK, the most serious allergic reactions tend to follow injections because the drugs are carried around the body more quickly.

Contrast agents/media

X-rays, CT scans, MRI scans or ultrasound scans sometimes require contrast agents/media injections for imaging purposes. They are typically iodine-based or gadolinium-based substances injected into a patient’s vein.

Contrast agents/media can cause an allergic reaction in some individuals, especially those with existing allergies, asthma or kidney problems, and those with previous allergic reactions to these substances.

In a report by the Resuscitation Council UK, contrast media accounted for 11% of fatal anaphylaxis cases in the UK. Severe reactions typically occur within 20 minutes of contrast agent administration.

According to the NHS, mild symptoms occur in up to one per cent of patients; severe symptoms are even rarer. If individuals do react, the symptoms are usually mild, e.g. flushing, itching, hives/rash, headache, nausea and vomiting, and they resolve quickly.


Natural rubber latex (NRL) comes from the milky sap of the tropical rubber tree (Hevea brasiliensis) grown in southeast Asia. Some individuals are allergic to the proteins in latex. Others may be allergic to the chemicals used in latex products.

According to Anaphylaxis UK, approximately 1-6 out of every hundred people could be sensitive to latex, but not everyone who is sensitised will have symptoms.

It is currently unknown how many individuals have a latex allergy. Studies at Great Ormond Street Hospital suggest that about 40 per cent of their patients have antibodies to latex, and up to half of the remaining patients are at risk of reactions. Individuals at an increased risk include those who have:

  • Allergies within the immediate family.
  • Had numerous surgeries and exposed to latex often, e.g. children with spina bifida.
  • Specific food allergies, e.g. banana, avocado, tomato, potato, kiwi and chestnut. These have proteins similar to latex.
  • To use latex products often, e.g. healthcare workers.

Latex is in everyday products and is found widely in healthcare. Here are some examples:

  • Medical gloves, e.g. non-sterile examination gloves and surgical gloves.
  • Single-use disposable gloves.
  • Balloons.
  • Adhesive tape, bandages and dressings.
  • Condoms and diaphragms.
  • Liquid latex.
  • Catheters.
  • Rubber bands.
  • Dental dams.
  • Tourniquets.
  • Resuscitation equipment.
  • Medical product packaging.

Patients have a higher risk of exposure to latex during medical and surgical procedures, e.g. smear tests, labour, surgeries and dental work, as it can come into contact with more absorbable surfaces, such as the mouth, vagina and bodily tissues.

If staff use powdered latex gloves, there is a risk of inhalation. The latex proteins can bind to the cornstarch powder in the gloves, which can become airborne during removal.

Cleaning agents

Various cleaning agents are present in healthcare settings for infection control, hygiene and skin preparation for surgical procedures. The type will depend on the healthcare setting and the risks. The most common cleaning agents likely to be used are:

  • Skin cleansers, e.g. soaps and detergents.
  • Skin antiseptics, e.g. chlorhexidine, povidone-iodine, potassium permanganate, emollients, etc.
  • Skin disinfectants, e.g. hydrogen peroxide.
  • Cleaning chemicals, e.g. alcohols, detergents, disinfectants, sanitisers and bleaches.

The likely route for cleaning agents to enter the body is via the skin, although eye contact and inhalation are possible, depending on the substance form. Healthcare staff are at risk, as well as patients.

Some individuals can react to certain ingredients in cleaning agents and develop allergies, such as allergic contact dermatitis. When they come into contact with the substance or even those similar, dermatitis will occur. There is also the risk of severe allergic reactions when agents enter the bloodstream through dermal absorption.

Some cleaning agents can contain nuts, dairy, wheat, or soy, which are a risk to individuals with food allergies. They can also have ingredients known to cause reactions in some, e.g. limonene, linalool and hexyl cinnamal.

Eight million people are living with a skin disease in the UK. Some are manageable, others are severe enough to kill (Allergy UK). However, according to the NHS, allergic contact dermatitis is less common.

Allergen identification and labelling

Healthcare providers must ensure they identify all allergens in their settings to prevent, control and manage the risk of allergic reactions in patients, staff and visitors. The procedure for identifying allergens will be specific to each healthcare provider and setting.

Here are some examples of how healthcare providers/professionals and patients can identify allergens in a healthcare setting (this list is not exhaustive):


  • Check the labels of pre-packed food or drink for any of the 14 allergens emphasised in the ingredients list.
  • Check supplier’s documentation, e.g. ingredient specification sheets, for products delivered without a label.
  • Check menus or ask catering staff if meals contain any allergens.
  • Look out for alternative names for allergens, e.g. albumin, ovalbumin or ovomucin for egg.

Medicines and drugs, including contrast agents and media

  • Check the list of active ingredients on medicine/drug packaging and labels (if allergenic ingredients are present, e.g. egg, peanut, sesame, soya, wheat, there is usually additional information on the outer packaging).
  • Look at patient information leaflets and check the list of ingredients and possible drug side effects, including possible allergic reactions.
  • Check manufacturer documentation, e.g. product information sheets detailing whether there is a risk of an allergic reaction.
  • Search online databases with information on medicines and drugs that healthcare professionals and members of the public can access, e.g. electronic medicines compendium (emc) and MHRA Products.
  • Contact medical information services for further advice.


  • Check if the product is or contains rubber, as this could mean latex is present.
  • Check the name on the packaging to see if the product contains latex, i.e. Powder-free latex disposable gloves.
  • Check product labels for latex cautions/warnings, e.g., may cause allergic reactions in some individuals.
  • Look at manufacturer product data sheets, catalogues, manuals or an online seller description to identify the ingredients.
  • Contact manufacturers or suppliers if there is any doubt about a product containing latex.
  • Look out for alternative names for latex, e.g. Caoutchouc or caucho.

Cleaning agents

  • Check the labels for any ingredients that could cause an allergic reaction, especially for those with food allergies.
  • Look out for the hazard symbols and statements on labels, i.e. may cause an allergic skin reaction.
  • Look at the safety data sheets (SDSs) for any substances classed as hazardous, e.g. cleaning chemicals, as these contain vital health and safety information to help employers do a COSHH assessment.
  • Contact manufacturers and suppliers for further advice.
  • Follow the advice above for any drugs or medicines, e.g. skin cleaning agents.

Allergy assessment and patient history

To reduce the risks of allergic reactions in patients and help them manage their condition, competent healthcare professionals must take a detailed allergy-focused clinical history during assessments. According to NICE, it is key first step in the diagnosis.

Some questions healthcare professionals could ask during an allergy-focussed clinical history are as follows:

  • What allergen do they suspect?
  • Who has raised the concern and suspects they have an allergy?
  • What symptoms are they experiencing, the frequency, severity and duration? What did they experience during their last reaction?
  • When did symptoms first present, i.e. age?
  • What were they doing, and where were they leading up to their last reaction?
  • Are symptoms triggered by, or associated with, anything in particular?
  • Have they tried avoiding the allergen or excluding it from their diet, and has this had any effect?
  • Have they experienced any past allergies?
  • Is there a family or personal history of atopic diseases, such as asthma, eczema, hay fever, allergic rhinitis, or food allergies?
  • Are there any significant environmental factors at work or home relating to symptoms?
  • Does their lifestyle have any impact on their symptoms?
  • Do their reactions and symptoms have any impact on their quality of life?

Healthcare professionals should tailor the history to the patient’s age and the symptoms they are experiencing. It may be necessary to have parents, guardians, or carers answer if the patient cannot provide clear responses, e.g. young children, older people and those with mental incapacity.

It is also crucial to check medical notes for current medications, take a complete drug history and review previous laboratory results. They should note whether the patient has used any antihistamines, steroids or adrenaline (epinephrine) in the past.

It may be necessary to refer the patient to a specialist if the healthcare professional does not possess the correct competencies and/or NICE guidelines recommend referral for the type of allergic reaction. They may also need to arrange for immediate ambulance transfer to Accident and Emergency if there are signs of anaphylaxis.

After completing an allergy-focused clinical history, further assessment and tests may be required, such as skin prick tests, patch tests, immunoglobulin (Ig)E level measurements or oral food challenges.

A Guide to Allergens in Healthcare

Managing allergens in healthcare

All healthcare providers should have policies and procedures for managing allergens specific to their settings and activities. They should also ensure that healthcare staff are trained and understand their role in preventing, reducing and managing the risks of allergic reactions among patients, colleagues and visitors with allergies.

Communication between healthcare workers is of utmost importance. There have been cases in hospitals where patients with food allergies have been given the incorrect meals due to a lack of communication, resulting in anaphylaxis.

Individuals with a diagnosed allergy should have an allergy management plan tailored to their needs and circumstances, as they can reduce further reactions, and when they do occur, they tend to be mild (Anaphylaxis UK).

All healthcare professionals involved in diagnosing, managing and treating allergic patients and other healthcare workers, e.g. those preparing and serving food, must be aware of any allergies and follow employer policies and procedures and patient allergy management plans. They should also double-check with patients and ask them about any allergies.

There are some practical strategies healthcare providers and professionals can adopt to reduce the risk of allergic reactions. Here are some examples (this list is not exhaustive):


  • Keep allergenic foods separate from other foods.
  • Provide allergen-free meals where possible.
  • Inform patients, staff and visitors if any food products sold or provided contain any of the 14 allergens.
  • Train all healthcare staff on allergens and how to adopt high hygiene standards.
  • Handle and manage food allergens properly and avoid cross-contamination during food preparation and handling.

Medicines and drugs

  • Store medicines and drugs securely to prevent unauthorised access.
  • Ensure all medicines and drugs are properly labelled.
  • Document drug allergy status separately from adverse drug reactions and check with patients or family/carers before prescribing, dispensing or administering.
  • Use colour-coded equipment to avoid giving the incorrect medication to patients.
  • Update medical records or inform GPs of any change in drug allergy status.
  • Check for medical alert bracelets or necklaces.


  • Use latex-free products and adopt latex-free conditions wherever possible.
  • Risk assess and minimise the use of any latex products if there is no other alternative.
  • Use low protein and powder-free latex gloves if latex is required. The Health and Safety Executive has advice on selecting latex gloves.
  • Staff with latex allergies should avoid handling latex products or wearing latex gloves.
  • List, label, and store correctly and strictly control latex products.
  • Latex-sensitive patients should be identified and referred to specialists where necessary.

Contrast agents

  • Avoid contrast dyes where possible, or use another type of dye.
  • If contrast dyes are necessary, consider giving patients specific medication before the procedure to reduce the risk of reactions, e.g. antihistamines, steroids, or epinephrine.
  • Monitor patients with a history of drug reactions, allergies or hypersensitivity disorders closely during and after procedures.

Cleaning agents

  • Avoid cleaning agents that patients and healthcare staff are allergic to and encourage them to adopt good skin care practices.
  • Choose non-hazardous or less hazardous cleaning agents wherever possible.
  • Train healthcare staff on hazardous substances and where they could cause allergic reactions.
  • Produce COSHH assessments to assess the risks and identify the precautions required.

Further information on allergy management is on BSACI and NICE.

A Guide to Allergens in Healthcare

Emergency preparedness

A severe allergic reaction is a life-threatening medical emergency, as it can result in anaphylaxis and death if left untreated. If this situation occurs in a healthcare setting, the patient must receive prompt diagnosis and treatment to increase the chances of survival.

The emergency policies, procedures and protocols for handling allergic reactions will depend on each healthcare provider and type of setting. It will also depend on the severity of a patient’s symptoms and whether they have an allergy action plan.

There are some general procedures if an individual has symptoms of anaphylaxis. The British Resuscitation Council has resources on recognising and treating anaphylaxis here. NICE also has guidance for healthcare professionals on their webpage.

To ensure patients (or even staff) with allergies receive prompt treatment following an allergic reaction, all healthcare settings should have the following:

  • Trained and competent healthcare professionals who can recognise and diagnose allergic reaction symptoms and can treat and manage individuals or refer them to an emergency care provider.
  • Facilities, equipment and medicines to diagnose and treat allergic reactions. Smaller settings may have emergency allergy kits, and some allergic individuals carry medication, such as an adrenaline auto-injector (e.g. an EpiPen).
A Guide to Allergens in Healthcare

Patient Education and Advocacy

It can be challenging for individuals living with allergies, especially when first diagnosed, to navigate the healthcare system and know how to understand and manage their medical condition.

Patient advocacy is essential to ensure that those living with allergies and their families and carers have the correct support and access to a range of services that meet their needs.

Healthcare professionals have an important role in educating patients and their families or carers about the following:

  • Allergen risks.
  • Allergen avoidance advice.
  • Explanation of allergy management plans.
  • Anaphylaxis, including the signs and symptoms of an anaphylactic reaction.
  • The risk of a biphasic reaction.
  • Medicines for mild allergic reactions.
  • Emergency medicines for severe allergic reactions and a demonstration of the correct use.
  • Referrals to a specialist allergy service and the referral process (where applicable).
  • The importance of disclosing allergies and sharing information with healthcare professionals in the future.

Most healthcare providers will have their own resources, such as leaflets and guidance booklets, to give to patients or tell them where they can access the information online or via apps. Healthcare professionals should follow employer procedures and provide the correct literature where available. They can also follow advice in BSACI Professional Resources.

They can also signpost patients to numerous online resources, such as:

There are helplines on the British Society for Allergy and Clinical Immunology (BSACI) and support groups, such as the Sadie Bristow Foundation and the Official Allergy UK Support Group.

A Guide to Allergens in Healthcare

Regulatory Compliance

All healthcare providers are responsible for providing the highest standards of care to patients, staff and visitors. They also have various legal duties and must adhere to the laws and standards specific to their particular setting.

Some general laws will apply, such as:

  • Health and social care – the Health and Social Care Act 2008 (Regulated Activities) Regulations 2014 requires healthcare providers to identify and assess any dietary intolerances, allergies, and medication contraindications and follow specific requirements for medicines administration records.
  • Health and safety – the Health and Safety at Work, etc. Act 1974 requires employers to protect the health, safety, and welfare of all employees and others potentially affected by their work activities. It includes exposure to allergens and other substances that could cause harm to patients, staff and visitors. The Control of Substances Hazardous to Health Regulations 2002 will also apply.
  • Food safety – if healthcare providers provide food to patients, staff or visitors, they must comply with the Food Safety Act 1990 (as amended), Regulation (EC) 852/2004 and associated food safety and hygiene regulations. Where allergens are concerned, they must also provide the correct information to consumers  under:
  • The Food Information to Consumers (FIC) Regulation.
  • The Food Information Regulations 2014.
  • Natasha’s Law.

There are several professional resources and guidance available from:

Healthcare professionals will also be required to adhere to particular standards and guidance regarding allergens, as per the requirements of their specific regulatory body. For example, doctors must adhere to the General Medical Council’s professional standards to maintain registration and licensing.

A Guide to Allergens in Healthcare


Allergies are increasing, and healthcare providers will likely see more allergic individuals in their settings. They must have appropriate policies and procedures to identify and manage allergens and reduce the risk of allergic reactions among patients, staff and visitors.

Healthcare professionals are at the frontline regarding assessing, diagnosing, treating and managing patients with allergies. They must have the necessary training, competencies and access to information to help and support allergic patients and their families or carers.

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