Abstract Cases of contact dermatitis due to nickel andgold especially in pierced earlobes, are increasing innumber the world over. However, the presence ofthese metal fragments has not been demonstrated inthe skin lesions. The aim of this study was to demon-strate nickel and gold in contact dermatitis lesions inpierced earlobes. Skin specimens taken from such ear-lobe lesions were examined using scanning electronmicroscopy and x-ray microanalysis. The pierced ear-rings worn when the lesions appeared were examinedby the same techniques, and their analysis confirmed.In nickel dermatitis, small, electron-dense fragmentswere seen in the specimens examined by scanning elec-tron microscopy, and nickel was detected in locationscorresponding to these fragments by x-ray microanaly-sis. In contact dermatitis due to gold, small dense frag-ments containing gold were observed. It is suggestedthat small fragments of nickel and gold remain in theskin lesions of pierced earlobes for a long time, evenafter the studs have been removed, and cause pro-longed irritation and various cutaneous reactions.

Key words Nickel · Gold · Pierced earlobes · Contact dermatitis · X-ray microanalysis

Introduction

The prevalence of nickel hypersensitivity among femalesin the general population of several countries has been in-creasing [4, 5, 17, 18]. Sensitization to nickel has beenfound in 14.8% of women with pierced ears but only in1.8% of those without pierced ears [16]. Ear piercing thusappears to be an important risk factor for nickel sensitiza-

tion. In 1996, we showed that the nickel interliner beneaththe gold plating of both used and unused earrings be-comes exposed and sensitizes the skin, leading to contactdermatitis [11].

Gold itself can also cause contact dermatitis [16]. It hasbeen stated that contact dermatitis induced by gold is rare,since gold shows little tendency toward ionization and isalmost completely insoluble in bodily secretions [6, 7,10]. However, the insertion of gold earrings into piercedears greatly increases the chances of gold sensitization [7,10, 16]. Growing numbers of contact dermatitis cases dueto gold have recently been noted all over the world, espe-cially affecting pierced earlobes. Contact dermatitis due togold lasts for several months, even after the gold studs areremoved. It is suggested that the persistence of the der-matitis may be due to the persistent presence of gold in thedermis [6], and that prolonged contact between the goldand the dermis causes a granulomatous reaction [1, 6, 7].However, no metal fragments have been demonstrated di-rectly in skin lesions of contact dermatitis due to thesemetals. The aim of this study was to demonstrate metalsin the lesions of contact dermatitis due to pierced earrings.

Materials and methods

Crust and blood clots were removed from the pierced region of theearlobe skin of six patients with contact dermatitis, due to nickel inthree and due to gold in three, and who had positive patch test re-actions for these metals. The specimens were examined withoutdehydration, using a JSM-5410LV or JSM 5310LV scanning e1ec-tron microscope (Jeol Co., Tokyo, Japan) equipped with a JED-2100 energy dispersive x-ray microanalyzer (Jeol). The surfacestructure of the skin specimens was first observed backscatteredelectron images by scanning electron microscopy. When highlyelectron-dense material was seen in the tissues examined, colormap images of nickel or gold were prepared by phase analysis. Theelemental composition of the material was then determined by x-ray point microanalysis. The surfaces of the metal accessorieswere studied using the same instruments and the metal accessorieswere studied using the same instruments, and the metal con-stituents were determined to confirm the presence of metals likelyto cause contact dermatitis.

Hiroyuki Suzuki

Nickel and gold in skin lesions of pierced earlobes with contact dermatitis. A study using scanning electron microscopy and x-ray microanalysis

Arch Dermatol Res (1998) 290 :523–527 © Springer-Verlag 1998

Received: 19 September 1997

ORIGINAL PAPER

H. SuzukiDepartment of Dermatology, Surugadai Nihon University Hospital, Tokyo, 101 Japan e-mail: eg2h-szk@asahi-net.or.jp Fax +81-3-3293-3719

Results

Nickel was detected in the specimens taken from the skinlesions of contact dermatitis in an 18-year-old Japanesegirl. She had removed the studs about 8 weeks before, butthe skin lesions persisted. She had a positive reaction fornickel sulfate. In backscattered electron beam images ob-

tained by scanning electron microscopy, several smallelectron-dense fragments, 2.9 × 3.9 µm to 17.4 × 7.7 µmin size, were present here and there in the specimens, andhad released traces of similar dense substance into nearbynarrow sulci (Fig. 1). In color map images, nickel wasclearly demonstrated in each fragment, and the location ofthe dense substances seen in the narrow sulci corre-sponded to those of the dense substance detected by x-raymicroanalysis (Fig. 2). Large amounts of nickel, oxygen,carbon and sulfur and small amounts of phosphorus, chlo-rine and potassium were detected in these small fragmentsby x-ray point microanalysis (Fig. 3). On the surfaces ofthe earrings that the patients customarily wore and whichcaused dermatitis, small spherical pits were revealed bybackscattered electron imaging (Fig. 4). Large amounts of

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Fig. 1 Backscattered electron beam image obtained by scanningelectron microscopy of a skin specimen taken from an earlobe le-sion of nickel contact dermatitis. Small electron-dense fragmentsare present. Similar dense substances are apparent in the narrowsulci on the specimen

Fig. 2 Color map image of nickel obtained by x-ray microanaly-sis of the same location as shown in Fig. 1. Nickel is distinctly ap-parent in the same fragments and in the same narrow sulci as in thebackscattered electron beam analysis

Fig. 4 Scanning electron micrograph of the surface of an earringthat caused dermatitis when worn by the patient. Small pits of var-ious sizes can be seen

Fig. 3 X-ray point microanalysis of the small fragments seen inFig. 1. Large amounts of nickel (Ni), oxygen (O), carbon (C) andsulfur (S), and small amounts of phosphorus (P), chlorine (C1) andpotassium (K) were detected in these fragments

nickel were detected in the surface by x- ray point micro-analysis (Fig. 5).

At the same time, skin specimens from the earlobes oftwo other patients, Japanese women aged 22 and 23 years,were examined because these patients had shown positivereactions for nickel sulfate, and had worn earstuds andsuffered from contact dermatitis. However, no nickel wasdetected.

Gold was definitively identified in the specimens froman earlobe lesion in a 24-year-old Japanese woman whohad removed her gold studs 4 months before, but still haddermatitis lesions on her earlobes. Patch tests gave posi-tive reactions for gold chloride. Small electron-densefragments, 1.8 × 4.1 µm to 5.3 × 18.4 µm in size, wereseen in backscattered electron beam image (Fig. 6). In co-lar map images, gold was clearly observed in the locationscorresponding to these fragments (Fig. 7). A large amountof gold and carbon, and small amounts of silver, copperand oxygen were revealed by x-ray point microanalysis

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Fig. 5 X-ray point microanalysis of the surface of the earringshown in Fig. 4. Large amounts of nickel (Ni) were detected Fig. 8 X-ray point microanalysis one of the fragment seen in Fig.

6. Large amounts of gold (Au) and carbon (C) and small amountsof silver (Ag), copper (Cu) and oxygen (O) were found

Fig. 6 Backscattered electron beam images obtained by x-ray mi-croanalysis of a skin specimen. Small electron-dense fragmentscan be seen

Fig. 7 Color map images of gold seen In the same specimen as inFig. 6. Gold is clearly present in locations corresponding to thefragments

Fig. 9 Scanning electron micrograph of the surface of an earringcustomarily worn by a patient. Numerous small scratches and pitsare present

(Fig. 8). On the surface of the earrings usually worn bythe patients, a small number of scratches and pits were re-vealed by backscattered electron imaging (Fig. 9). Largeamounts of gold and small amounts of silver, copper, car-bon and oxygen were revealed, but no other metals weredetected (Fig. 10).

Skin specimens from the earlobes of two other Japan-ese women, 21 and 22 years old, were examined using thesame techniques, since they showed positive patch testsfor gold chloride and had worn gold studs. However, nogold fragments were detected in these specimens.

Discussion

It appears from the results that gold and nickel fragmentsderived from earrings for pierced ears remain in a skin le-sion for along time, even after removal of the accessories,and cause prolonged irritation and various cutaneous reac-tions.

Small nickel and gold fragments also readily peel offthe surface of the studs used after piercing, and these met-als were demonstrated in the tissues of patients who usedstuds and developed dermatitis lesions on the earlobe.

The mean retention time of nickel in the tissues may beof the order of 100s of days. A small residue of nickelcauses irritative inflammatory reactions and other medicalproblems, and results in various cutaneous reactions [3,10].Yoshikawa et al. [20] have stated that 0.05 µg ofnickel would induce contact allergy when released intothe wound of a freshly pierced ear. A high daily absorp-tion of nickel through the pierced skin takes place duringcontact. Thus, ear piercing is an important risk factor fornickel sensitization.

Gold- or silver-plated metal accessories including ear-rings are usually plated with an interlined of nickel beforethe final gold or silver plate is applied [11, 20]. It has beenreported that when ear piercing kits are kept in syntheticsweat nickel ions are released in various amounts from allthe objects examined [8, 18]. Since gold plating cannotprevent the release of nickel, nickel may be released intoboth the sweat and other dermal fluids where the earlobes

are pierced. The author and colleagues [11, 19] havedemonstrated by scanning electron microscopy and x-raymicroanalysis that numerous pits of various sizes in whichthe nickel interliner is directly exposed, are present at thesurface of both used and unused gold- or silver-plated ear-rings. They have also shown that nickel is easily releasedthrough these small pits, leading to an irritative inflamma-tory reaction and sensitization of the skin [11, 18]. Recentlegislation in Europe to prevent such cutaneous involve-ment will lead to the replacement of nickel interlinerswith nonallergenic interliners [15].

Nodular lesions shown histopathologically to be be-nign lymphoplasia have been reported in a case of nickeldermatitis due to earrings [15]. It has been postulated insuch cases that the lesions are induced by nickel frag-ments which remain for a long time in the dermis.

Oxygen, carbon, sulfur, phosphorus, chlorine andpotassium were detected on the fragments examined, but,since these elements were not contained in the earringsexamined, they must have been derived from the skin tis-sues.

It has long been believed that contact dermatitis in-duced by gold is rare because of its very low degree ofionization and very low solubility in bodily secretions [6,7, 10]. However, Kligman [13] has demonstrated thestrong sensitizing potential of gold chloride and suggeststhat gold would be as troublesome as nickel if it were asreadily solubilized by skin secretions. The insertion ofgold studs into earlobes during the ear piercing proceduregreatly increases the chances of gold sensitization [6, 10].

Small gold fragments were detected in the specimensobserved in the present study. It is suggested that, even af-ter the studs were removed, gold fragments, as well asnickel, persisted in the dermis, continuously stimulatingthe skin and causing the various skin reactions. The au-thor [l9] show has shown that the gold layer becomeseasily eroded from the surface of gold-plated silveracupuncture needles implanted in the dermis. Usually,gold or gold-plated studs are inserted immediately afterthe earlobes are pierced, which permits direct contact be-tween the earrings and the dermis, with consequent con-tinuous dissolution of a small amount of gold into the tis-sue fluid [6].

Since contact dermatitis tends to persist for severalmonths and can cause granulomatous changes, it is classi-fied into two types, called persistent allergic dermal con-tact dermatitis [6, 7] and granulomatous contact dermati-tis [9]. Kobayashi et al. [14] have reported the case of a38-year-old Japanese woman with a large lymphocytomacutis induced by 24-carat gold studs and earrings in anearlobe. The lesions in this patient grew and persisted for20 years, although the patient had removed the earringswithin a few weeks and had not worn them again.

Lymphocytic infiltrations [2, 10, 12] and epithelioidcell granuloma due to gold studs and earrings have beenreported. These reports seem to support our suggestionthat gold from pierced earrings persists for a long time inthe skin and causes various cutaneous reactions. In thesestudies, small amounts of silver and copper were also ob-

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Fig. 10 X-ray point microanalysis of the surface of the earringshown in Fig. 9. Large amounts of gold (Au) and small amounts ofsilver (Ag), copper (Cu), carbon (C) and oxygen (O) were identi-fied, but no other elements were detected

served in the fragments found in the skin, and were com-ponents of the gold alloy examined. To prevent cutaneousreactions, titanium and stainless steel piercing kits arepreferred. These kits should be used for at least 3 to 4weeks, until the channel is completely epithelialized.

Acknowledgements This work was partly supported by a grantfrom QP Co., Ltd., to Hiroyuki Suzuki. The author thanks Mr.C.W.P. Reynolds for linguistic assistance in the preparation of themanuscript.

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