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Can you trust online allergy tests?

Allergy test

Have you ever had an allergic reaction? Did you take a test to confirm whether you actually have an allergy? Here’s Victoria from Sense About Science on why you need to think twice before buying online allergy tests.

When I found myself covered in hives last week, I was pretty sure it was an allergic reaction. But to what? Should I be avoiding a certain type of food, face moisturiser, or trying to keep indoors on high-pollen days?

My concerned housemate kindly sent me links to lots of allergy tests she’d found online. It seems I could simply pay for a test to find out what I was allergic to. But they were pricey – many were upwards of £100! So do these tests really work? Fortunately, a recent part of my work at Sense About Science made me particularly sceptical and eager to hang onto my cash.

Making sense of allergies

With the help of leading experts, we have just launched a new guide, Making Sense of Allergies. These experts warned us that many of the available tests are based on dubious scientific evidence, and there is no one allergy test that can alone diagnose an allergy.

From their insights, it seems there is still a lot that specialists don’t know about the causes of allergies, but it is important that what they do know is not drowned out by misinformation. It is around these uncertainties that misleading information about causes, conflicting advice, and an opportunistic market in dodgy tests and treatments has developed.

With allergies on the rise it’s no surprise then that many of us are confused by allergies, unsure if we have one, or what to do about it. Doctors see many people on unnecessarily restricted diets or taking potentially harmful treatments, having followed the advice of invalid tests. Tariq El-Shanawany, Consultant Clinical Immunologist, said:

‘It might feel reassuring to get a quick result from a test you have found online, but if it’s misleading it’s a waste of time.’

Getting your allergies tested

Even the best allergy tests cannot be 100% certain, the experts say. We’d advise that allergy testing needs to be done under the care of a medical professional in conjunction with a face-to-face consultation, because results from the tests must be considered in the context of the patient’s medical history.

Experts are concerned that ineffective tests and other kinds of self-diagnosis are creating a large proportion of people who think they have an allergy when they don’t, and dangerous allergies are trivialised.

Fortunately, my allergic reaction wasn’t life threatening. But my sister-in-law’s carrot allergy is (she can barely go near one without needing an Epi-pen). I’m now going to visit my GP, rather than shelling out for a dubious test.

What’s your experience with allergies? Have you ever seen any allergy tests? Did you buy one instead of visiting your GP?

Which? Conversation provides guest spots to external contributors. This is from Victoria Murphy, Programme Manager at Sense About Science. All opinions expressed here are Victoria’s own, not necessarily those of Which?


I have a very high regard for the output of Sense About Science which works on a very small budget but produces first rate work . I have read the pdf. cover to cover just now and it sharpens up my thinking. I do get emails from three of the organisations quoted so in some respects I thought I knew more than I did.

A gripe:
” Most allergy tests and natural treatments offered on the high street and online have no scientific basis. These ineffective tests and other kinds of self diagnosis are creating a large proportion of people who think they have an allergy when they don’t. One study found 34% of parents reported food allergies in their children but only 5% actually had an allergy. Myths about artificial additives, junk food and immunisations causing allergies are also contributing to self diagnosed allergy.

The use of percentages without actual figures . This is something I am veruy surprised at coming from the charity. I thought clarity on figures would be a given.

Two minor observations and not SaS’s remit:
It may be too recent but I see that many people are complaining about the re-formulated Lenor even to the extent that the “fragance” can affect people around them. This may be an area to explore if people are being affected.

The problems of pollens etc in clothing and indadequate rinsing to clear the pollen. Or this may be the drying of clothes out of doors taking on a new load of pollen. I wonder if this might provide allergic reactions out of pollen season?

Keep up the excellent work : )


Dieseltaylor – Regarding the percentages mentioned in the Making Sense of Allergies guide, a reference to the relevant paper is provided: http://onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2007.01570.x/epdf This states that the number of children in the study was 969. This article is cited by over 100 other articles, indicating it has generated some interest in the field.


Thanks for your comment (and to Wavechange below for sharing the reference and pulling out the sample size!). I hadn’t heard of the effects of fabric conditioner fragrance affecting people. If we start seeing these claiming ‘hypo-allergenic’ or ‘allergen free’, I think it would be on to ‘Ask for Evidence’ about.


Hi Victoria. My breathing is affected by various fragrances used in various household products. The worst is air fresheners that release a scent continuously, such as plug-in devices and porous sticks that sit in a reservoir of fragrance. After an hour or two I have to go and use an inhaler or get rid of them. Years ago I learned that fragrances that affect me often have a potent smell. I have met other asthmatics who find that fragrances that affect them also have a very strong smell.

When buying laundry detergents I have a quick sniff at the (unopened) box, which is enough to tell me what to avoid.


I don’t just sniff the unopened box, I take the tops off anything with a fragrance and smell them. (I wouldn’t dream of doing it to anything with a shelf life or if it was sealed of course.)

Strong fragrances can make me sneeze and feel sick and fabric conditioners have very strong smells. I only have to smell them when I can’t get my regular one or they discontinue my current product. They might also give me a rash although other chemicals in the product could be to blame, never quite worked that one out.

Washing powders and liquids can definitely give me a rash and I dread a product being discontinued or a change in the ingredients.


Manufacturers do change the formulation of their products for various reasons. It may be to make them more effective, cheaper to manufacture, safer or to be better for the environment (such as removal of phosphates from laundry detergents). Sometimes these changes can be seen on the material safety data sheet (MSDS), but this only mentions ingredients that could be harmful.

I would like to see all ingredients in products listed, as they are on most foods. This could help those that suffer from skin irritation and allergies to identify the problem.

Fabric conditioners are best avoided because they are added to the final rinse and remain on the fabric. I don’t want a bunch of unknown chemicals on my clothes and bedding.


Whether it is the fragrance or other ingredients, I can have just as much a problem with soaps, hand-wash, shampoos and conditioners and even sun-tan lotion. They rarely do more than make me itch, but there has been many a time when I have had to return to a washroom and hold my hands under the cold tap until the itching subsides.

Are chemicals in fabric conditioner really that much different to all the other chemicals we subject ourselves to?


Alfa – The problem is that we don’t know what is in fabric conditioners and other household products. Manufacturers are required by law to tell us what is in most foods, though there are numerous exceptions including alcoholic drinks and bakery products. Manufacturers are also at liberty to change the ingredients of their products. If the product has been improved, the manufacturer will probably label it as ‘new improved’ but if the change has been made to decrease production costs, we are unlikely to find out.

Some chemicals wash off the skin and fabrics easily, whereas others do not. Saffron would be a good example. Some chemicals are intended to remain on the skin for a long time (e.g. sun tan cream) and others to remain on fabrics (e.g. fabric conditioners) that may be in contact with the skin for an extended period.

Without knowing what is in products, anyone suffering from skin irritation or an allergy could have great difficulty in knowing what to avoid. I have lost count of the number of chemicals that have been withdrawn from household and garden products since I did a chemistry degree in the early 70s.

Manufacturers rarely tell us which chemicals are in their products and we cannot even make a Freedom of Information request because companies are exempt.

GPs often prescribe a non-sedating antihistamine for people like you who suffer skin irritation. It would be better to know what causes the problem and avoid products containing that ingredient.