About allergy and eczema

Allergic disorders are on the increase in the UK and across the world, affecting up to 40% of the population. Allergic disorders include food allergy, eczema, asthma and allergic rhinitis (commonly known as ‘hay fever’). They also include reactions to specific allergens such as medicines and insect stings.

What is an allergy?

An allergic reaction is an immune response to a substance to which the person has become sensitised. A substance that causes an allergic reaction is known as an allergen (e.g. pollen, animal dander, dust, certain foods and chemicals). Many allergens are harmless in themselves but in sensitised individuals cause the body to overreact. Allergies can be broadly divided into two groups: immediate and delayed allergies.

Who gets allergies?

We are unsure why some people develop allergies and others don’t. We are aware of factors which make it more likely that a child will develop some form of allergic disease, such as family history. Children who are born into a family where their parents or siblings have some form of allergic disease are more likely to develop allergic disease themselves. However, as a parent you do not pass on the specific allergy (i.e. if you are peanut allergic, this does not mean your child will be peanut allergic), rather you pass on the predisposition for your child to develop allergic disease of some sort, be that eczema as a young baby or hay fever in adulthood.

People who are predisposed to develop allergic disease are known as atopic individuals. We know that babies with eczema in the first few months of life have an increased risk of developing food allergy.

The skin is a protective barrier and keeps bacteria, viruses and allergens out of the body. Those with eczema have a disturbance in this barrier, and we now believe that this disturbance is a route which allows allergens to enter and sensitise the body.

What are the criteria for getting a referral for allergy testing?

The criteria for allergy testing is based on the patient’s best interests. There are three types of allergy testing for foods: IgE blood tests, prick tests and challenge tests. No one test is 100% reliable and usually a combination of tests is undertaken. The interpretation of these tests requires an expert in allergies or dermatology to review the results, as it is often not a clear-cut process.

Allergy testing referral on the NHS is considered appropriate for people with symptoms of an immediate allergy, that is, an allergy occurring within a few seconds of eating a food and up to two hours after eating the food. Symptoms include vomiting, lip swelling, tongue and throat swelling, hives and difficulty breathing.

Allergy testing is also appropriate for people with moderate to severe eczema which cannot be controlled with topical treatments. If your eczema is moderate to severe, it is likely that you will be under the care of a dermatologist, with whom you can discuss the merits of allergy testing further.

Although environmental allergens, such as pollen and grasses, can be tested for, testing is not routinely carried out, as the knowledge that you are allergic to them does not change the outcome. The expectation is that all patients with eczema should take steps to minimise environmental allergens where they can, for example, by closing windows when pollen counts are high. With time, patients will come to know what makes their eczema worse, and can avoid the relevant allergens without needing the allergy confirmed with a test result.

Private allergy testing can be arranged directly if you are self-funding. If you are arranging the testing through a private medical insurance provider, a doctor’s referral is still required.

Artificial nails

Allergy to artificial nails

Acrylates are used widely in a wide range of products and processes – from aircraft manufacturing to dentistry. In recent years, there has been a sharp increase in allergic contact dermatitis due to acrylates, driven by the explosion in nail bars. Dr Sophie Rolls, dermatology specialist registrar at Cardiff and Vale University Health Board, explains. This article was published in Exchange 177, September 2020.

Acrylates have long been recognised as a common cause of allergic contact dermatitis (ACD). However, recently there has been a striking increase in sensitisation to acrylates across the UK and Europe, and further afield, in Singapore and the United States. In 2012, the American Contact Dermatitis Society named acrylates Contact Allergen of the Year and has since included acrylates in the US baseline patch test series.

The increased frequency can be explained by a shift in occupational and recreational exposure – away from traditional industries associated with acrylate allergy, such as dentistry, and towards the beauty industry, where there is soaring demand for nail fashion with UV-cured gel, shellac nails and glue – all of which contain acrylates.


  • ACRYLATES are chemical molecules or monomers that bind together in a process called polymerisation to form acrylic plastics. Their use is widespread: from the graphic and printing industry to aircraft manufacture, orthopaedic cement, surgical glue, dressings, dentistry – for example, in white fillings set under ultraviolet (UV) light – and, more recently, in nail fashion. In this article, we refer to them throughout as ‘acrylates’.
  • ALLERGIC CONTACT DERMATITIS is a form of eczema caused by an allergic reaction to a substance, known as an allergen, in contact with the skin. The allergen is harmless to people that are not allergic to it. Allergic contact dermatitis is also called contact allergy.

How is it caused?

ACD is a delayed hypersensitivity reaction. In ACD, a person’s immune response is induced by a particular sensitising substance, known as a ‘contact allergen’ – in this case, an acrylate monomer. The first phase is called sensitisation, or induction. At this stage the person becomes immunologically sensitised although they show no symptoms. When the person is re-exposed to the same substance, or something that reacts with it, this triggers the next phase: elicitation. This activates an individual’s immune system and symptoms become apparent.

The appearance of ACD will depend on which area is affected. Unsurprisingly, ACD to acrylates is most commonly seen on the fingertips and nails.

Symptoms can include:

  • NAIL DYSTROPHY distortion and discoloration of normal nail-plate structure
  • ONYCHOLYSIS loosening or separation of a fingernail or toenail from its nail bed. This usually starts at the tip of the nail and progresses back
  • HYPERKERATOSIS thickening of the nail
  • FISSURING and SPLITTING of the fingertips and inflammation of the nail fold.

Symptoms may be found not only around the nail area but also in areas that are commonly touched, such as the eyelids, mouth, chin and sides of the neck. However, uncured acrylate monomers can cause symptoms anywhere on the body that they touch. Symptoms include patches of streaky, red, tight, dry and itchy skin, characteristic of eczema. Diffuse eyelid eczema is also often seen in ACD to nail enamels and removers.

Who’s at higher risk?

Acrylate monomers are a well recognised cause of ACD. However, people with atopic eczema are at higher risk of ACD since their skin barrier is damaged, which increases the penetration of allergens and irritants (substances that causes irritation). In some cases, it can be difficult to distinguish between ACD and atopic eczema.


Once someone becomes sensitised to acrylates, their symptoms will persist, as long as they use acrylic nails and glue containing these allergens. The symptoms can be alleviated with standard eczema treatment, such as soap substitutes, emollients and topical corticosteroids. However, the definitive treatment is to avoid the offending allergen.

There are many acrylate allergens. If someone has suspected allergy to acrylic nails, they can identify which allergen they are sensitised to through patch testing by a dermatologist to the (meth)acrylate series. However, even if an individual is allergic to just one single acrylate – for example, 2-hydroxyethyl methacrylate (the commonest acrylate that people are sensitised to) – it is best to avoid acrylates altogether.

This is because acrylates are known to crossreact. This means that a person who is allergic to one acrylate may be sensitised to other acrylates since they all have similar chemical structures. Also, acrylic nail products contain a number of different acrylate allergens, which can cause concomitant sensitisation, and this makes it is difficult to identify the exact allergen to which an individual is sensitised.

Application and removal process

The step-by-step nail application and removal process highlights the many points at which someone can become sensitised to acrylates:

  1. First, the consumer chooses their colour from an expansive array.
  2. The nails are filed and shaped. The cuticle, which is a protective seal, is pushed back and removed and therefore damaged.
  3. A primary layer of gel polish containing acrylate monomers (the active allergen) is applied to the nails and each hand is then placed underneath the UV lamp for 30 seconds, allowing time for the active acrylate monomers to polymerise into their inactive form.
  4. This cycle is repeated until two coats of colour and a finishing coat are completed.
  5. The removal process involves filing the nails, soaking them in acetone for 15 minutes – which is highly irritant – and then scraping off the gel polish.
  6. Acrylic nails are then frequently re-applied.

There are many points at which an individual can become sensitised to acrylates during the application and removal of acrylic nail fashion.

NAIL TRAUMA Because the nail is traumatised in the application and removal process, any uncured monomers can easily penetrate the broken cuticle, nail fold or damaged skin barrier.

SKIN CONTACT If any skin is touched by a nail coated with uncured acrylate monomers, these monomers can be transferred to the skin and cause sensitisation.

Many gel polishes require a specific UV or LED lamp to ensure the acrylate monomers are polymerised. If there is a mismatch between the gel polish and the lamp, or the hands are placed under the lamp for the incorrect amount of time, not all the monomers will be polymerised into their inactive form, or ‘cured’. A nail with uncured monomers carries a risk of sensitising wherever it touches.

It is important that this is accurately diagnosed so that the person understands to avoid acrylate allergen, since allergy to these chemicals can have lifelong consequences – such as avoiding future dental treatments and surgeries containing acrylates.

Nail technicians

Nail technicians are at high risk of occupational exposure to acrylates. The more you are exposed to an allergen, the more likely you are to become sensitised. Nail bars are ubiquitous on every high street and nail technicians are often young people working in poor – sometimes slave-like – conditions, as highlighted in media reports. Nail technicians are often inadequately trained on the correct use of personal protective equipment and the potential health risks associated with acrylates.

To tackle the problem, there have been calls for increased regulation, better training and personal protective equipment for nail technicians, along with better labelling and a national registration process to monitor growing popularity of artificial nail fashions and surveillance on the incidence of sensitisation – particularly among consumers using kits at home.

In an attempt to protect workers, the Hair And Beauty Industry Authority (HABIA) has produced a code of practice for the nail industry. This includes wearing nitrile protective gloves. The Health and Safety Executive, too, outlines health and safety in nail bars. Premises in the UK providing manicures and nail extensions are required to be registered under ‘massage and special treatment premises licensing’ – but this is overseen on a regional basis by local authorities, and criteria vary. Any increase in future incidence of sensitisation should be kept under surveillance.

Alternatives to nail gel

Unfortunately, all nail enamels – including removers and artificial nails – contain allergens to which people can become sensitised. The most common is tosylamide formaldehyde resin. Hypoallergenic nail enamels that use polyester resin or cellulose acetate butyrate may be an alternative, but sensitivity is still possible, and they are less durable and scratch resistant.

Limit your risk

  • Manage eczema as normal with your maintenance therapy.
  • If you work in the beauty industry, make sure you understand the risks and that your employer provides you with adequate training, nitrile gloves and face masks. If symptoms persist, you may need to consider changing profession.
  • Always read instructions carefully for UV lamps.
  • If your eczema is resistant to your usual treatment and you are in contact with acrylates, consider the possibility of ACD. Contact your GP who can organise a referral for patch testing.

For more information on allergy and eczema, please see our Allergy factsheet