A 69-year-old woman presented to the clinic at Midwestern University College of Dental Medicine-Arizona with a chief complaint of sporadic, unresolved burning sensations on the dorsum and tip of the tongue that began shortly after a COVID-19 infection in July 2020.
The patient reported these tongue symptoms to an otolaryngologist in August 2020 and was diagnosed with hairy tongue. After recovering from COVID-19, the patient experienced erratic hypo-hyper thyroid levels, chronic urinary tract infections (UTI), and genital herpes which she had not previously demonstrated. The patient’s physician advised that her immune system had been affected.
A 9300 nm CO2 laser was set on low power mode for all three LEA sessions, with settings of an 0.012 cm2 spot size, 20% cutting speed, and no mist, corresponding to an irradiance of 33.3 W/cm2. The average irradiated area was 12 cm2.Treatment time was 12 minutes for the first session, and 6 minutes each for the remaining two sessions, for a total radiant energy of 86 joules. All treatment sessions were performed using 20% benzocaine topical anesthetic and high-volume evacuation.
The 9300 nm CO2 laser with LEA and epithelial stimulation successfully removed the hyperkeratotic papillae and alleviated the patient’s symptoms immediately after treatment. Other effective approaches by Jung et al using a CO2 laser and Samiei et al with diode laser treatment for hairy tongue incorporated unilateral local anesthesia.
Laser LEA treatments for this and other oral lesions, such as erosive lichen planus and spongiotic gingivitis, have been successfully managed with only a thin application of 20% topical benzocaine.
Since CO2 wavelengths are highly absorbed in water and the superficial epithelial layer, the desiccated appearance or “white spots” that were noted during LEA treatment appear to be ablated epithelial cells or keratin proteins. The thermal effects from LEA treatment may also contribute to bacterial and fungal disinfection, as shown in other laser studies. Compared to surgical scalpel techniques, CO2 lasers also minimize post-operative pain and swelling.
This case report described a novel palliative treatment for a painful, persistent, and refractory HFLP with the use of a 9300 nm CO2 laser with LEA. The patient reported immediate and long-term improvement of oral symptoms with this laser application.
Another consideration when weighing this treatment approach is that along with removing hyperkeratotic papillae, LEA therapy may have antibacterial and antifungal properties that help promote successful resolution of HFLP.
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