Nickel deposition and penetration into the stratum corneum after short metallic nickel contact: An experimental study

Abstract

Background: Knowledge about the skin deposition and penetration of nickel into the stratum corneum (SC) after short contact with metallic items is limited.Objective: To quantify nickel skin deposition and penetration into the SC after short contact with metallic nickel.Methods: Sixteen nickel-allergic participants and 10 controls were exposed to 3 pure nickel discs and 1 aluminium disc on each volar forearm for 3 × 10 minutes. Before exposure, 1 forearm was irritated with 0.5% sodium lauryl sulfate under 24-hour occlusion. Immediately, as well as 24 and 72 hours after metallic disc exposure, outer SC layers were removed with adhesive tapes and the nickel content was measured.Results: Nickel deposition and SC penetration capable of eliciting allergic nickel dermatitis were found immediately and after 24 hours. Significantly higher nickel amounts were found on normal skin and in the SC of nickel-allergic participants than in controls both immediately and after 24 hours, and on irritated skin immediately after exposure.Conclusions: Nickel deposition and SC penetration is considerable after nickel skin exposure of 3 × 10 minutes. Combined with the allergic responses resulting from the same exposures reported previously, this study highlights that short skin exposure to nickel-releasing items may cause allergic nickel dermatitis. K E Y W O R D Scontact allergy, nickel allergy, nickel penetration, nickel release, nickel skin dose, stratum corneum, tape stripping

Nickel allergy and allergic contact dermatitis: A clinical review of immunology, epidemiology, exposure, and treatment

“…Nickel skin exposure (μg/cm 2 ) has been measured in nails and in the skin with various types of wipe sampling, finger immersion, and tape stripping . Following sampling, the nickel content is analysed, for example, by inductively coupled plasma mass spectrometry.…”

“…Historically, prolonged metal‐skin contact has been expected to be required for critical nickel skin deposition . However, more recently, rapid skin deposition following contact has been shown to occur after seconds to minutes . Erfani et al found that 4.7 μg of nickel per cm 2 was deposited onto the fingertip following 3 seconds of contact with metallic nickel, and Ahlström et al showed nickel skin doses of 10.1 to 23.5 μg/cm 2 after three 10‐minute exposures .…”

Short contact with nickel is not harmless

“…Furthermore, Nixon et al state that the nickel elicitation threshold is linked specifically to the duration of exposure, as it requires corrosion of the material to release nickel ions. However, this statement is incorrect, as high amounts of nickel are, indeed, deposited within seconds and minutes of skin contact …”

“…Without any supporting literature, Nixon et al claim that nickel skin doses needed to elicit allergic nickel dermatitis may rarely be exceeded by contact with nickel‐releasing metallic items. However, substantial nickel skin doses capable of eliciting allergic nickel dermatitis have been measured following both experimental and real‐life occupational exposure to nickel‐containing materials . We are concerned that Nixon et al misleadingly discuss and cite a study by Jensen et al, in which considerable nickel skin doses were found on the hands after the performance of normal work tasks for 2 hours.…”

“…Nixon et al also mention that that a certain amount of time is needed for nickel ions to penetrate the skin, by citing a study that used tape stripping . However, very rapid nickel penetration is indeed possible through skin shunts such as sweat glands and hair follicles; this is not measured by the tape stripping method …”