Test / Diagnostic Procedure: Drug provocations and challenges

A drug provocation test (or challenge) is where a drug is given slowly in gradually increasing amounts to diagnose or rule out a true drug allergy. Please call the Centre to discuss pricing

To book offline, call our Skin Health and Allergy centre directly on: 02036532007

Enquiries: bookings.skinhealthallergy@onewelbeck.com

What is a drug provocation or challenge?

A drug provocation test (DPT), also known as a drug challenge is a medical procedure in which a drug is given slowly (as tablet/syrop, injection, inhalation – depending on the drug), in gradually increasing amounts to diagnose or rule out a true drug allergy. It is done when a medical history and allergy tests (skin/blood tests) are inconclusive (for example in case of suspected penicillin allergy) or if no routine laboratory tests are available (for example in case of suspected Aspirin allergy). Sometimes it is used to assess tolerance to an alternative drug for example, if a patient is allergic to an antibiotic, another antibiotic of the same or different family is tested.

Most DPTs are performed openly, meaning that both the patient and doctor know what drug is being given. In blinded challenges, either the patient (single-blind), or both the patient and the doctor (double blind) do not know whether the real test drug is being eaten or a placebo.

The procedure takes from 2-6 hours depending on the drug tested and severity of the index reaction.  Sometimes the same drug needs to be taken after DPT for a few days to rule out a delayed reaction.

What are the risks?

The risks of the DPT include allergic rash, swelling, stomach upset (nausea, vomiting) and anaphylaxis. DPT is always performed under medical supervision and with full access to the relevant emergency treatment. Some patients complain of subjective symptoms that may be due to fear of reaction.

What do I need to do in preparation?

You need to be in good health on the day of the test. Chronic allergic conditions such as asthma, atopic dermatitis/eczema and hay fever have to be well controlled so they do not interfere with the interpretation of any symptoms. Antihistamines have to be stopped 3 days before the DPT since they might mask mild early symptoms. Intranasal steroids and antihistamines, antihistamine eye drops, leukotriene antagonist or inhaled corticosteroids for asthma do not need to be stopped.

Test / diagnostic pricing

Please contact the centre to discuss pricing.



Health Insurance

This service or treatment is generally covered by most health insurance policies. You are responsible for checking your insurance policy cover, and you may need a referral letter. Check which insurance companies are covered.


Self-Pay Available

This treatment is available for self-paying users. If you would like to see more information on pricing visit our pricing and payments page.


Consultation Required

For this treatment you will need to have a 1-to-1 consultation at OneWelbeck first. To book in with our team of expert clinicians or to find out more about the process contact the relevant centre team.


Self Referral

No doctor referral needed in order to book this service, although health insurers may require a referral in order for your treatment to be covered.


Next Day Availability

We usually have next day availability for this service, please call us to check availability.