Botulinum toxin for chronic parotid sialadenitis: A case series and systematic review

OBJECTIVE: To evaluate salivary gland chemodenervation with botulinum toxin in chronic parotid sialadenitis. METHODS: Patients who underwent parotid gland chemodenervation for chronic sialadenitis due to duct stenosis refractory to siaendoscopy were reviewed (case series). Additionally, a systematic review of the literature on botulinum toxin injection for chronic parotid sialadenitis was performed. Inclusion criteria included studies containing original data on botulinum toxin injections in patients with chronic sialadenitis symptoms. RESULTS: Sialadenitis symptoms from 10 patients with 13 affected parotid glands were examined. All had duct stenosis diagnosed on sialendoscopy, refractory sialadenitis symptoms, and received parotid onabotulinum toxin injection(s) (median dose 65U). Of patients with 3‐month follow‐up, 78% reported significant improvement in symptoms. Mean Chronic Obstructive Sialadenitis Symptoms (COSS) Score improved at 3 months post‐injection (47‐25.9, P = .039) with significant reduction in gland pain frequency and gland swelling severity. No patients had a facial nerve paralysis or increased xerostomia. With the systematic review, 518 abstracts were reviewed and 11 studies met inclusion criteria and included case series or case reports with a total of 40 patients treated with botulinum toxin for chronic parotitis. Thirty‐four out of a total of 35 patients in the studies (97%) reported complete (9, 26%) or partial (25, 71%) improvement in sialadenitis symptoms with minimal complications. CONCLUSION: Parotid gland chemodenervation with botulinum toxin is a minimally invasive treatment option for symptomatic chronic sialadenitis refractory to medical treatment or sialendoscopy. Botulinum toxin injections alleviate gland pain and swelling associated with salivary obstruction and provide an alternative to parotidectomy for recurrent sialadenitis. Level of evidence: 4.