Cutaneous and Oral Eruption from Oral Exposure to Nickel in Dental Braces

Abstract and Introduction

Oral eruptions due to nickel allergy are rare. A common presentation of intraoral contact dermatitis is the presence of lichenoid plaques on the buccal mucosa adjacent to the offending antigen. We report an unusual case of cutaneous and mucosal nickel allergy arising after placement of dental braces. An 11-year-old boy was referred by his orthodontist to the University of Minnesota Occupational and Contact Dermatitis Clinic to be evaluated for a possible metal allergy. The patient developed an itchy rash on his abdomen and under his wristwatch 1 week after dental braces were placed. He was diagnosed with allergic contact dermatitis from nickel. The patient avoided cutaneous nickel exposure and had a minimal resolution of his symptoms. One year later, the patient developed swelling and burning of the lips. Secondary to extreme discomfort, the braces, which contained nickel, titanium, and zinc, were removed. The patient underwent standard patch testing; the final reading at 96 hours showed a +++ reaction to nickel, palladium, cobalt chloride, and neomycin. The patient experienced relief of his oral symptoms after removal of the braces. No current relevance to palladium, cobalt, or neomycin has been found.

Nickel is the most common contact allergen for adults. The North American Contact Dermatitis Group, a multicenter collaborative research patch-test group in the United States and Canada, found that of 5,800 patients who were patch-tested from 1998 to 2000, 16.2% had positive reactions to nickel.^[1] Worldwide, the prevalence of nickel allergy in the general population ranges from 0.9 to 14.9%.^[1,2,3] Some experts believe that the prevalence of nickel allergy is increasing in adults, adolescents, and children.^[1,4] Wohrl and colleagues found that 34.2% of 79 children aged 1 to 10 years and suspected of having contact allergy had positive patch-test reactions to 5% nickel sulfate.^[5]

Risk factors for developing nickel allergy include gender and family history but not atopic disease. Nickel allergy is more common among women than among men; initial sensitization in women is thought to occur through ear piercing. A Finnish study of college students found that 42% of the female participants with pierced skin had positive reactions to nickel whereas only 14% of the females without pierced skin had positive reactions.^[6] Family history has also been associated with nickel allergy. Silverberg and colleagues reported that 80% of children allergic to nickel in one study had a first-degree relative with nickel allergy.^[2] A retrospective chart review by Magina and colleagues found that atopic individuals were no more likely to develop hand dermatitis secondary to nickel allergy than were nonatopic individuals.^[7]

The most common presentation of nickel contact dermatitis in children who do not wear jewelry is pruritic periumbilical papules adjacent to the site of contact with metal waistband buckles and clasps. Children who wear jewelry present more commonly with pruritic papules, vesicles, and eczematous dermatitis directly under the jewelry. Classic sites include the earlobes (from earrings), wrists (from watches or bracelets), and neck (from necklaces). Id reactions may also occur, typically on the upper arms and thighs, and can persist for months in children.^[2] Oral eruptions due to nickel allergy are rare.

The most common clinical presentation of intraoral contact dermatitis is a lichenoid plaque or erosion on the buccal mucosa adjacent to the offending antigen, which is often a component of dental amalgams.^[8] Palladium and mercury commonly cause oral allergic contact dermatitis. The prevalence of palladium allergy ranges from 2.5 to 10.0% of subjects tested with a standard patch test series; interestingly, 93 to 100% of patients with positive palladium patch-test results also have positive results on nickel patch tests.^[9] Marcusson suggested that nickel reactivity might be a marker for reactivity to other metals.^[10] Among patients with oral lichenoid eruptions, the frequency of positive results on patch tests for mercury is 4 to 33%.^[9]

Sensitization to dental metals has been shown to be more common among adults with lichen planus and lichenoid lesions. In a prospective study of 51 adults with mucosal lichenoid eruptions, 76.9% had at least one positive patch-test reaction. Nickel and thimerosal were the most common antigens in this study. The thimerosal allergy was attributed to previous vaccinations and was not thought to be relevant; however, the nickel positivity was thought to be an initiating factor in these patients' disease.^[11]

In general, nickel-sensitive patients are not at an increased risk of developing an oral eruption after dental work when compared with patients who are not sensitive to nickel.^[12] It has been proposed that oral nickel exposure may actually protect patients from cutaneous nickel allergy.^[13] Van Hoogstraten and colleagues suggested that oral exposure to nickel induces a specific T-cell tolerance, preventing subsequent cutaneous hypersensitivity.^[14] Marigo and colleagues reported that continuous oral exposure to nickel might modulate nickel sensitivity through oral tolerance, which they demonstrated through in vitro cell proliferation assays.^[15] Working with 132 nickel-sensitive adolescents, Kerosuo and colleagues found that dental braces may reduce nickel sensitivity and that there may be a protective threshold for oral tolerance to nickel.^[12] Haudrechy and colleagues reported that previous oral nickel exposure through dental appliances prevented 51 patients from developing allergic contact dermatitis from nickel after ear piercing.^[16]

The objectives of this report are to present a review of the literature and to describe a unique case of cutaneous and mucosal nickel allergy arising after the placement of dental braces.

Dermatitis. 2004;15(3) © 2004 American Contact Dermatitis Society

Cite this: Cutaneous and Oral Eruption from Oral Exposure to Nickel in Dental Braces - Medscape - Sep 01, 2004.