We present the case of a 23-year-old female patient, allergic to Penicillin, presenting erythematous, fissurated and scaly itching lesions, affecting bilateral and symmetrically the dorsum of fingers and hands for the previous seven months (Figure 1). She was working as a prosthodontist a month before the lesions came out, and noticed that oral and topical corticosteroids improved them, but they reappeared after the treatment completion.
Moreover, she had been wearing orthodontics for one year, and during the last months she had started to note itching and a burning sensation in lips and oral cavity, which also improved with the cycle of oral corticosteroids.
Patch testing was performed with the Spanish standard series (TRUEtest®, ALK-Abelló, Madrid) and the metals and the acrylates series, including manganese (Trolab®). These tests only revealed positivity to manganese chloride 5% pet. (++), following the International Contact Dermatitis Research Group (ICDRG) guidelines, in which the results were checked after 48 and 96h. All of the other products tested, including nickel sulphate, were negative. With these results our diagnostic was allergic contact dermatitis in hands and oral cavity due to manganese in a prosthodontist with orthodontics.
Manganese is a transitional metal (group 7 of the periodic table of the elements) which seems to have a limited potential to cause allergic contact dermatitis. However, it is being increasingly used in the manufacture of dental prosthesis as a nickel substitute1. Consequently, there are a few clinical cases reported in literature and most of them are related to dental prosthesis2,3, and only one to aluminium alloy4.
Those described in oral mucosa can show stomatitis, with diffuse oedema and erythema, as well as aphthous lesions, or pain and burning sensation, with white lesions in oral cavity, clinically and histopathologically compatible with oral lichen planus.
To date, we have found only one article referring to cutaneous lesions due to allergic contact dermatitis to manganese4. They are described as eczematous lesions in palms and fingers, similar to our case, but in a worker making blind rails, handling aluminium.
Some authors consider that manganese is not the main causal factor of these reported cases and suggest some other theories, such as nickel impurity in patch test preparations, or concomitant reactions among transition metals of the same group of the periodic table5. On the other hand, other authors affirm that sensitivity to metals of the same group is frequent, but only for nickel and chrome6,7.
In our case, we checked a negative result for nickel, so the theories of the concomitant reaction and nickel impurity in patch test are not completely feasible.
In conclusion, we present a case of allergic contact dermatitis to manganese, evidenced by eczematous lesions in the dorsum of fingers and hands, and itching lesions in lips and oral cavity, due to the management of prosthetic material and orthodontics respectively. Therefore, we suggest that a metal series containing manganese should be included in the evaluation of stomatitis in patients wearing dental prosthesis or orthodontics, or eczematous lesions in a prosthodontist.
