Fissured tongue: a sign of tongue edema?

Fissured tongue (FT) is a condition frequently seen in the general population. Clinically, FT is characterized by grooves that vary in depth and are noted along the dorsal and/or dorsolateral aspects of the tongue. Furthermore, FT presents many enlarged, smooth filiform papillae and subepithelial inflammatory infiltration. Despite of many studies, the etiology of FT remains obscure. FT is believed to be a congenital anomaly associated with several disorders and with geographic tongue (GT). We hypothesize that FT is not a congenital anomaly, and FT with swollen filiform papillae may represent edema in the subepithelial tissue of the tongue. According to the literature, the difference in prevalence among different age groups indicates that FT is not a congenital disorder. FT appears to occur more commonly in adults, and it is very rare or not at all in children younger than 10 years old. An association between FT and GT is well established in the literature, supporting the results of previous authors suggesting that FT might be a consequence of GT. The most remarkable finding in the region of swollen papillae of FT samples has been the subepithelial infiltrates of polymorphonuclear leucocytes and lymphocytes causing the subepithelial edema. The clinically visible grooves and large edematic papillae clustered on the region of the fissures might be caused by the inflammation and edema underneath the epithelium. In the future, FT and GT must be researched together as two different entities of the same disease so that GT is a prestage of FT. The diagnosis of FT must be taken to consideration whether the tongue surface have smooth and swollen papillae or normal-appearing filiform papillae.