Researchers in Israel have found a connection between the measles virus and common painful mouth ulcers, known as recurrent aphthous ulceration (RAU). RAU is a common condition, with some studies showing that 20% of the world population has suffered RAU.

In the study, researchers took tissue specimens from ulcers in the mouths of three healthy men, aged 18 to 19, who suffered minor RAU. The men had episodes of RAU about twice a month for more than 2 years. All had received the measles vaccine.

The tissue samples of the three individuals with RAU all tested positive for the measles virus compared to samples taken from control subjects which did not.Researchers speculate that even in vaccinated individuals, a symptomless measles infection could result in mouth ulcers.

When the measles virus attacks, it reduces levels of a receptor known as CD46, which is found on the surface of body cells. The men with RAU had low levels of CD46 in their mouth tissue -- suggesting a measles infection -- while the men without RAU had high levels.

Archives of Dermatology 2000;136: 801-802