Persistent Vocal Fold Inflammation After Injection of Hyaluronic Acid Gel

Significance Statement

This report underscores the efficacy of hyaluronidase in managing persistent inflammation following hyaluronic acid (HA) injections for vocal fold paralysis. In 2 cases where corticosteroids were ineffective, hyaluronidase successfully resolved HA-induced complications. This highlights the importance of considering hyaluronidase as a therapeutic option when standard treatments fail in similar cases. The authors have obtained written informed consent from the patients for the publication of this case report.

A 66-year-old female with a history of anterior cervical discectomy and fusion and subsequent right vocal fold paralysis presented with dysphonia. She underwent multiple injection medialization procedures with calcium hydroxyapatite. Despite several courses of voice therapy and injection procedures, the patient continued to experience a gradual decline in voice quality characterized by raspiness, fatigue, and difficulty with projection.

Strobovideolaryngoscopy revealed hypomobility of the right vocal fold and glottic insufficiency. She underwent microdirect laryngoscopy with HA injection to the right vocal fold. At 1-week and 1-month follow-up, inflammation and stiffness were observed in the right vocal fold (Figure 1). A Medrol dose pack and voice therapy were recommended.

Figure 1.

Strobovideolaryngoscopy at 1 month shows inflammation and stiffness in the right vocal fold.

Subsequent CT scans at 2 and 24 months demonstrated minimal resorption of the hyaluronic acid filler without appreciable change in the medialized position of the right true vocal fold (Figure 2). Steroid (dexamethasone) was injected into the affected area of stiffness without resolution of symptoms. After 15 months, the inflammation was still present. Due to the persistent stiffness and dysphonia, 1 mL of hyaluronidase (HA-ase; 150 U/mL) was injected into the right vocal fold and was followed promptly by significant improvement in her voice and mucosal wave. Repeat CT imaging confirmed interval resolution of surrounding mucosal edema.

Figure 2.

CT of the neck shows minimal resorption of hyaluronic acid filler without appreciable change in the medialized position of the right true vocal fold.

The second patient was a 71-year-old college professor with a history of heart transplant who presented with 3 years of dysphonia. He was diagnosed via stroboscopy with bilateral vocal fold atrophy, glottic insufficiency, and muscle tension dysphonia. Despite voice therapy, he continued to experience voice fatigue and difficulty projecting his voice. He underwent microdirect laryngoscopy with a hyaluronic acid injection to both vocal folds. One week later, he presented to the emergency department (ED) with a low-grade fever (99.5), headache, fatigue, sore throat, hoarseness, and decreased oral intake. A laryngoscopy performed in the ED demonstrated inflammation and erythema in the vocal folds (Figure 3). He was admitted for observation, IV steroids, antibiotics, and pain control. CT of the neck demonstrated mucosal edema involving the right greater than the left side of the larynx, most prominently involving the right aryepiglottic fold. This was more prominent than expected given the patient’s surgery 1 week previously and suspicious for superimposed inflammation/infection (Figure 4). His symptoms improved, and he was discharged. Two weeks later, he presented to the Otolaryngology clinic for injection of hyaluronidase.

Figure 3.

This image demonstrates inflammation and erythema of the vocal folds after augmentation.

Figure 4.

CT of the neck shows mucosal edema involving the right greater than the left larynx.

By the time of his next follow-up 2 weeks later, he had experienced relief of symptoms. Stroboscopy showed a reduction in vocal fold edema with an improved mucosal wave. He had 2 additional HA-ase injections and reported a resolution of the dysphonia.

HA is used commonly in the management of vocal fold hypo/immobility and glottic insufficiency with improvement in function and quality of life. ¹ It carries a very low risk of adverse effects ranging from hematomas to inflammatory reactions. ² Such inflammatory reactions have been managed with low-dose corticosteroids in previous studies. ³ Hyaluronidase injection in the vocal folds has been used previously in the management of HA over-injection, Reinke’s edema, and vocal fold hemorrhage. ⁴ In cases in which steroids fail to provide relief of inflammation following HA injection, such as the 2 patients described, it is important to recognize the utility of hyaluronidase for further management.