Effectiveness of booster dose of tetanus and diphtheria toxoids (Td) vaccine in management of recurrent aphthous stomatitis: a prospective, randomized, triple-blind and placebo-controlled clinical trial

[[[ Background: ]]] Recurrent aphthous stomatitis (RAS) is the most common oral disease. The activation of the immune system by vaccines might reduce the interactions between oral mucosa and microorganisms. [[[ Aim: ]]] To evaluate the effect of the tetanus-diphtheria toxoids (Td) vaccine in management of RAS. [[[ Design and setting: ]]] This prospective, randomized, triple-blind and placebo-controlled clinical trial study was conducted on 70 eligible patients with minor RAS at the dermatology outpatient clinic. [[[ Method: ]]] Finally, a total of 66 participants (48 male, 18 female; mean age: 38.56 ± 10.98 years) completed the study in two groups, one in which colchicine and a single dose of vitamin B6 (placebo group) was treated and one in which colchicine and a single dose of Td vaccine (intervention group) was treated. [[[ Results: ]]] After six months of follow-up, the patients were evaluated, which revealed significant effects of the Td vaccine on pain intensity, ulcer size, recovery time, and the interval between episodes. At the end of the six month follow-up, 27 patients (81.8%) in the intervention group and 13 patients (39.4%) in the placebo group showed partial or complete recovery, and there was statistically significant difference between the groups ( p < .001). Recovery was not significantly associated with sex, education level, marital status and duration of RAS. However, occupation and positive family history of RAS had significant relations with recovery. [[[ Conclusions: ]]] A booster dose of Td vaccine had relatively favorable effects on pain intensity and recurrence of RAS, but further research is needed to confirm its efficacy.