Objective: This is a multicentric, observational and controlled study designed to verify the existence of a significant association between plaque-type psoriasis and oral lesions, such as geographic tongue and/or fissured tongue.
Study design: during a period of 9 months all consecutive patients with plaque-type psoriasis were enrolled using simple nonrandom (sequential) sampling. The control group included healthy subjects presenting to the same Dermatology centers to monitor pigmented skin lesions; the patients were matched for age and sex. All patients were examined for oral lesions.
Results: Out of a total of 535 psoriatic patients and 436 control group patients, oral mucosal lesions were detected in 188 (35.1%) and 86 (19.7%) cases, respectively, and the difference is statistically significant. Fissured tongue (FT) and geographic tongue (GT), which were most frequently detected, were seen more frequently in psoriatic patients (FT: 22.6%; GT: 9.1%) than the control group (FT: 10.3%; GT: 5.2%) (p<0.05).
Conclusions: On the basis of the similar studies reported in the literature and the large number of patients involved in our study, we can conclude that FT and GT can be clearly suggested as oral manifestations of plaque-type psoriasis, although the reason for this association is not clear.