Geographic tongue is a mucous inflammatory disease of unknown etiology. The typical clinical findings are wellcircumscribed red depapiliated areas of the dorsal aspect of the tongue delineated by an elevated whitish-yellow annulus. The histopathological findings are parakeratosis and psoriasiform hyperplasia with neutrophilic infiltration into the epithelium.[1
] There have been many reports regarding the association between geographic tongue and psoriasis.[2
] Since geographic tongue is usually asymptomatic and only rarely does significant pain develop and persist,[5
] patients do not usually require any treatment. Symptomatic treatments have not been evaluated rigorously. The use of systemic cyclosporine has been reported in the treatment of geographic tongue.[7
] Our patients complainedthat the lesional pain was strong. We tried various therapies including topical corticosteroid ointment for their painful condition but those treatments were not effective. Considering the histological similarity between geographic tongue and psoriasis, we introduced topical tacrolimus ointment. Within two weeks, their troublesome condition was improved without any side effects and no exacerbation was found after the follow-up period of 2 months.
Tacrolimus is an immunosuppressive macrolide and its anti-inflammatory action is similar to that of cyclosporine, which involves the inhibition of interleukin 2 (IL-2) production by T cells.[8
] As well as pimecrolimus, topical formulations of tacrolimus have beenestablished for the treatment of atopic dermatitis. Recently, topical tacrolimus has been shown to be effective in the treatment of other dermatoses such as erythematodes[9
], seborrheic dermatitis[11
], oral lichen planus[13
] and psoriasis. In 2009 The American Academy of Dermatology guidelines for psoriasis therapy with topical tacrolimus were recommended for facial and intertriginous psoriasis.[14
] Because of its high molecular weight (822.03), tacrolimus hardly penetrates through the stratum corneum when it is applied to normal skin. Since the permeability of the barrier becomes greater in the mucosa and/or in the lesional skin of inflammatory skin disorders, tacrolimus easily penetrates the barrier and exerts immunosuppressive actions after topical use. Sometimes, topical tacrolimus causes stinging at the application site, but our two patients did not complain about stinging after its topical use.
The results of therapies on two patients are difficult to interpret because of the possibility that the observed response may merely reflect the natural course of the disease rather than the effect of the medication. However, in our case, we believe that a real therapeutic effect took place because the persistent lesions have not recurred with topical tacrolimus. Further clinical trials are warranted to confirm the efficacy and the safety of topical tacrolimus for geographic tongue.