COVID-19 transient snoring (CVTS): Clinical and laboratory description.

Dear Editor,

In an attempt to complement the syndromic picture of the coronavirus disease (COVID‐19), a wide range of neurologic, gastrointestinal, dermatologic, and even oral symptoms adjacent to the severe acute respiratory syndrome coronavirus 2 (SARS‐COV‐2) infection has been recently reported. While consensus about the nonrespiratory symptoms is strongly advocated through rigorous reporting guidelines, this series gives an account of transient snoring symptoms experienced by laboratory‐confirmed COVID‐19 patients; and for better communication, this complication will be referred to as COVID‐19 transient snoring (CVTS). The clinical and laboratory findings of nine consecutive patients with CVTS have been reported according to the CARE guidelines.

The referenced consecutive patients sought care at the emergency department of our hospital during March and April 2020 due to a range of chief complaints related to respiratory infection; therefore, a polymerase chain reaction (PCR) test of nasopharyngeal swabs for SARS‐COV‐2 was performed, and they were all positive (Table 1). The mean value of the cycle threshold (C t) was 26.67 ± 6.67 (12–35).

Table 1

Demographic, Clinical, and Laboratory Characteristics of COVID‐19 Cases with Transient Snoring

No.	Gender	Age	BMI	Smoking	Comorbidities	C t	Fever	Cough	Nasal discharge	Ageusia	Anosmia	Snore score (T0, T1, T2) a
1	Male	42	31	No	D.M.	24	No	Yes	No	Absent	Absent	(52, 12, 4)
2	Male	59	32	No	None	26	Yes	No	Yes	Absent	Absent	(62, 15, 5)
3	Female	26	20	No	None	24	No	Yes	No	Absent	Absent	(45, 19, 8)
4	Male	36	19	No	D.M.	27	No	Yes	No	Absent	2 weeks	(48, 13, 6)
5	Male	61	24	No	None	30	No	Yes	No	Absent	Absent	(52, 12, 7)
6	Female	40	26	No	None	35	No	No	Yes	Absent	Absent	(61, 11, 5)
7	Male	51	22	No	None	33	No	No	No	Absent	Absent	(49, 10, 5)
8	Female	39	29	Yes	D.M. and asthma	12	Yes	Yes	Yes	1 month	1 month	(71, 49, 32)
9	Female	47	27	Yes	D.M.	29	Yes	Yes	Yes	Absent	2 weeks	(49, 21, 10)

Abbreviations: BMI, body mass index; C t, cycle threshold; D.M., diabetes mellitus.

Snore score of SnoreLab was recorded at baseline (T0), after 1 month (T1), and after 2 months (T2).

Five (55.6%) patients were males; 4 (44.4%) patients were females. The mean age was 44.56 ± 11.19 (26–61) years old. The mean value of body mass index (BMI) was 25.56 ± 4.67 (19‐32), with 4 (44.4%) patients of normal weight (18.5–24.9), 3 (33.3%) patients were overweight (25–29.9), and 2 (22.2%) patients were obese (30–34.9). Only 2 (22.2%) patients were healthcare workers (a dentist and a staff nurse), while the rest did not hold health‐related jobs.

More than half of them (55.6%) were medically free, while 3 (33.3%) patients had diabetes type‐2, and 1 (11.1%) patient had diabetes type‐2 and asthmatic. While 7 (77.8%) patients were nonsmokers, 2 (22.2%) patients were smokers. In regard to the typical COVID‐19 symptoms, 3 (33.3%) patients had a fever, 6 (66.7%) patients had a dry cough, and 4 (44.4%) patients had a nasal discharge. Ageusia (loss of taste) was experienced by only 1 (11.1%) patient, and it lasted for 1 month. Anosmia (loss of smell) was experienced by 3 (33.3%) patients, and it lasted for 2 weeks in two patients and for 1 month in the third patient. None of the patients required admission to the hospital, and their clinical course of COVID‐19 was either mild or moderate. After 2 weeks from their PCR testing, all the investigated patients repeated their PCR tests, which turned out to be negative.

On their initial diagnosis with CVTS, none of the patients had reported any related sleep disorders in the past, and this was their first time to experience snoring symptoms. The intra‐oral examination revealed no characteristic local lesions, while some of them complained of diarrhea (11.1%), otalgia (11.1%), myalgia (22.2%), ostalgia (11.1%), and gastrointestinal disturbance (11.1%). The patients were instructed to use SnoreLab (Reviva Softworks Ltd.) while they are sleeping to assess the intensity of snoring and the baseline (T0) results after one (T1) and two months (T2) for all the patients were recorded. All the patients used iPhone smartphones (100%). A noninvasive protocol was developed to treat all the patients consisting of lifestyle recommendations regarding the sleeping position, nutrition, and caffeine uptake. The mean snoring score at T0 was 54.33 ± 8.49 (45–71), at T1 was 18 ± 12.2 (10–49), and at T2 was 9.11 ± 8.78 (4–32). A one‐way within‐subjects analysis of variance test yielded a significant decrease in snoring intensity over time in all the patients; Wilks' λ​​​​​​​ = 0.013, F(2,7) = 262.486, p < .001.

Compared with the baseline examination, visualization of the oropharyngeal airway has increased gradually during the two months of follow‐up. Figure 1 demonstrates the visualization of the oropharyngeal airway of the patient (No. 5) at baseline examination when the hard palate was only visible (Mallampati Class IV), after 2 weeks when the soft palate and base of uvula were visible (Mallampati Class III), after 1 month when the soft palate, fauces, and uvula were visible (Mallampati Class II), and after 2 months when the soft palate, fauces, pillars, and uvula were visible (Mallampati Class I). After 2 months, 8 (88.9%) patients had a snoring score below 10; however, only 1 (No. 8) patient required further follow‐up due to her relatively higher snoring score. This 39‐year‐old female patient was a staff nurse working in one of the hospitals dedicated to COVID‐19 patients, and she is believed to be infected during her work. Her clinical course was moderate as she had the lowest viral‐load cycle threshold (C t) value of 12, and she experienced persistent ageusia and anosmia in addition to fever, cough, and nasal discharge. She also had two comorbidities (diabetes mellitus type‐2 and bronchial asthma), and her systemic symptoms included ostalgia and gastrointestinal disturbance. All the investigated patients agreed to use their clinical and laboratory results for academic purposes while concealing their identifying personal data.

Figure 1

(A) Oropharyngeal patency of patient No. 5 at baseline corresponding to Mallampati Class IV. (B) Oropharyngeal patency of patient No. 5 after 2 weeks corresponding to Mallampati Class III. (C) Oropharyngeal patency of patient No. 5 after 1 month corresponding to Mallampati Class II. (D) Oropharyngeal patency of patient No. 5 after 2 months corresponding to Mallampati Class I

A recent systematic review has revealed that pharyngeal erythema, nasal congestion, and tonsil enlargement were common otolaryngological symptoms among COVID‐19 patients, thus increasing the possibility for transient snoring; however, none of them was reported by our patients. An epidemiologic study of COVID‐19 pediatric patients in China has revealed that dry and wet snoring symptoms were observed in cases with a moderate clinical course of the infection. As uvula and soft palate play a critical role in snoring development, uvular edema (UE), which is a rare but debilitating condition, may be triggered by ACE inhibitor drugs and upper respiratory tract infections. However, isolated UE was not clear in this series; viral enanthem of SARS‐COV‐2 was clearly observed in the palate of a recently reported case series, thereby increasing the odds for other complications that may affect this region. In a cohort of 22 post‐SARS patients in Toronto who were followed up for 36 months, average sleep efficiency was reduced to 77.4%, with some of them showing daytime sleepiness associated with snoring. This finding was highly attributed to fatigue and psychological distress, which is too early to be observed in our series. Snoring associated with other viral infections like seasonal influenza and herpes zoster is usually associated with obstructive sleep apnea symptoms. ,

To the best of the authors' knowledge, this series is the first evidence on nonapnea snoring cases associated with SARS‐COV‐2 infection. However, the cause and pathophysiologic course remain unclear; further similar cases of CVTS should be reported to better understand this novel complication.

CONFLICT OF INTERESTS

The authors declare that there are no conflict of interests.