Lingual fungiform papillae were absent or scanty in eight and significantly reduced in three out of 13 patients with the characteristic features of Behcet's syndrome. Examination was made by slit-lamp or by eye microscope. The finding is not pathognomonic. It is seen in the Riley-Day syndrome and has also been seen in 8 of 150 varied medical outpatients but in none of 40 healthy persons. Fungiform papillae were plentiful in six patients with severe aphthous stomatitis, and in five patients with uveitis only.
Davis E, Melzer E. A New Sign in Behcet's SyndromeScanty Fungiform Papillae in Tongue. Arch Intern Med. 1969;124(6):720-721. doi:10.1001/archinte.1969.00300220072013