Botulinum Toxin Injection for Chronic Parotitis: A Multi-Center and Prospective Trial.

OBJECTIVE: When conservative therapy fails for chronic parotitis, sialendoscopic treatment or surgical excision can be considered. However, these are financially costly or invasive. Thus, this study aimed to evaluate the clinical efficacy and safety of botulinum toxin (BTX) injection and to further analyze its effect on parotid gland function and volume using salivary single-photon emission computed tomography (SPECT)-computed tomography (CT). METHODS: This clinical trial has been registered in the Clinical Research Information Service, Republic of Korea. Fourteen patients with chronic parotitis received BTX injections into the parotid glands. Pain, postprandial pain, swelling, aesthetic discomfort, and salivary flow rate were assessed before injection, at 2 weeks, and at 1, 3, and 6 months. Salivary SPECT-CT was performed before injection and again 3 and 6 months after to assess the volume and uptake changes. RESULTS: All subjective symptoms decreased significantly until 1 month and then increased. However, at 6 months, all subjective symptoms were determined to be better than before injection. The unstimulated and stimulated salivary flow rate did not show a significant difference over time. No significant difference was noted in parotid gland volume or uptake on salivary SPECT-CT over time. CONCLUSION: BTX injection can be an alternative treatment option for chronic parotitis. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1903-E1909, 2021.