Adverse reactions to orthodontic appliances in nickel-allergic patients.

Nickel allergy (NA) is common and causes more cases of allergic contact dermatitis (ACD) than all other metals combined. Many orthodontic appliances (ODAs) contain nickel but their clinical relevance in nickel-allergic patients is unclear. We aimed to characterize the relationship between NA and ODAs because the medical literature investigating this is controversial. A survey concerning adverse reactions to ODAs in patients with NA was distributed to members of the Wisconsin Society of Orthodontics. Forty-three surveys were analyzed. The surveyed group was experienced, representing a mean of 21.2 years in practice and averaging 242 appliances placed per year per orthodontist. Most new patients with orthodontia were 10-18 years old. Most wires used were nickel-titanium alloy. Although 76% of orthodontists inquired about NA at initial evaluation, 37% still placed nickel-containing ODAs in known nickel-allergic patients. Fifty percent placed a single intraoral appliance, observing for reactions. Three orthodontists applied ODAs to the skin similar to patch testing. Only 8 patients with reactions to ODAs were described in detail, 6 were female patients and 6 were aged 13-14 years. Intraoral and extraoral reactions were mild; diffuse urticaria was reported in one patient. Treatment included removing the appliances or changing to nonnickel alternatives with favorable outcomes. These cases, which included >33,000 patients, suggest a prevalence of 0.03%. Adverse reactions to ODAs in patients with NA have been observed but are uncommon. Using suitable alternatives, patients usually can be accommodated.