Nickel sulfate

What is nickel sulfate?

Nickel sulfate is a chemical substance used as a diagnostic allergen in patch testing. In the clinical trial records provided, it appears as Nickel(II)-sulfat, 6*H2O 5%, Testsalbe, a test ointment containing 5% nickel sulfate hexahydrate for cutaneous use.^[1] Nickel sulfate is one of the most common contact allergens and is used to test whether a person has an allergic reaction to nickel, which is found in many everyday objects such as jewellery, coins, and metal fittings.

How does nickel sulfate work?

In patch testing, nickel sulfate is applied to the skin under an occlusive patch for a defined period. If a person is sensitised to nickel, immune cells in the skin recognise the allergen and trigger a local allergic reaction, visible as redness, swelling, or small blisters at the test site. The trial data describe the use of nickel sulfate as part of a metal panel to evaluate diagnostic efficacy and safety of investigational allergens.^[1]

Which conditions is nickel sulfate used or studied for?

• Allergic contact dermatitis — a skin reaction that occurs when the skin comes into contact with a substance to which a person is allergic. Patch testing with allergens such as nickel sulfate helps identify the trigger.
• Eczema — a condition involving inflamed, itchy skin. The withdrawn trial record listed eczema among the conditions studied.^[1]

How is nickel sulfate given?

Nickel sulfate is applied to the skin as a test preparation. In the trial, the nickel sulfate test ointment was applied cutaneously at a volume of 20 microlitres per application.^[1] The preparation is used in patch testing, not as a treatment to be taken by mouth or injected.

What do the clinical trials show?

The clinical trial data include two records for the same study, a phase 3 trial titled Metal Panel Patch Test. One record is authorised and enrolled 395 participants, while a related record with the same identifier is marked as withdrawn and listed 300 participants.^[1]

What is measured in the trial?

The primary outcome was the concordance, or agreement, between two patch testing methods: the hydrogel investigational allergen and the petrolatum reference allergen. Agreement was calculated using Cohen's kappa and by positive and negative percent agreement.^[1] This measures how reliably the investigational test matches the established reference method.

Who can take part in the trial?

The trial studied people with allergic contact dermatitis, and the withdrawn record also listed eczema. The study was interventional, meaning participants received the test allergens, including nickel sulfate, as part of the metal panel.^[1] The authorised record enrolled 395 participants.

What side effects are known?

The trial brief summary states that the study evaluated the safety of the investigational allergens and the overall safety and performance of the investigational panel device.^[1] The data provided do not include a separate list of side effects for nickel sulfate.