Congenital Absence of the Uvula
The results of the preparticipation sports physical of a healthy 12-year-old boy were normal except for an unusual finding in his posterior pharynx. The boy’s palate was normal and intact upon palpation with a gloved hand, but he did not have a uvula (compare our patient, A, and a different 12-year-old boy with a typical-appearing uvula, B).
When the absence of a uvula was pointed out to his mother, she said that she had never noticed that before, nor had she been told about it at visits to the pediatrician. The patient had a negative past medical history, with no recurrent otitis media, speech or growth problems, or neurologic or developmental concerns. He had no history of cleft palate, immune deficiencies, or dysmorphic features. Because there was no other explanation for the finding, the boy was given a diagnosis of congenital absence of the uvula.
Congenital absence of the uvula is rare in the general population, and the medical literature about it is scant. In a study of intraoral findings and anomalies of neonates, Jorgenson and colleagues1 reported only one case of absent uvula in 2,258 oral examinations in a well-baby nursery. A uvula absent at birth infrequently can be associated with genetic conditions such as cerebrocostomandibular syndrome, anhidrotic ectodermal dysplasia, Apert syndrome, and hyperimmunoglobulin E syndrome2; these conditions are accompanied by other features that were not present in this patient. Bifid or absent uvula associated with nonsyndromic isolated cleft palate also has been described.3 Bifid uvula associated with a submucous cleft occurs when the palatine shelves fail to completely fuse, resulting in the splitting of the inferior part of the uvula.
The function of the uvula in human physiology is a subject of ongoing debate and many hypotheses. This band of connective tissue, glands, and small muscle fibers appears to play a small role in functions such as speech, lubrication of the throat, and central support of the palatopharyngeal arch during closure of the nasopharynx while swallowing.4,5 The authors of a study comparing the soft palates of 8 different mammals found that the human uvula is unique: Its mix of serous and seromucous glands and large excretory canals, which are absent in other mammals, allow it to produce a large amount of saliva in a short time.6 The authors hypothesized that because the uvula and the ability to speak set humans apart from other mammals, the uvula might have a role in the speech process.6
An acquired absent uvula may be secondary to surgery or cultural practices, or it may be a complication of infection. Although uvulectomy has been used to treat chronic pharyngitis, cough, and sleep apnea, it is not seen as effective for these conditions. Traditional healers in sub-Saharan Africa remove the uvula for chronic cough and a variety of throat conditions.7 A common morbidity of uvulectomy is increased dryness of the oropharynx, with reports of as many as 31% of patients experiencing dryness after 1 year8,9 and up to 60% after 3 years.10 However, another study showed that 10% of patients complained of hypersecretion of saliva 2 years after uvulopalatopharyngoplasty.11
Absence of the uvula is among the diagnostic signs of rhinoscleroma,12 a chronic disease accompanied by fibrosis of structures in the oropharynx and nasopharynx that leads to formation of granulation tissue and scarring down of the uvula. Endemic to Africa, Southeast Asia, and Central and South America, it is caused by Klebsiella pneumoniae subsp rhinoscleromatis and is treatable if found early.12 Rhinoscleroma should be in the differential diagnosis of any patient with an absent uvula who is from an area where this disease is endemic.
REFERENCES:
1. Jorgenson RJ, Shapiro SD, Salinas CF, Levin LS. Intraoral findings and anomalies in neonates. Pediatrics. 1982;69(5):577-582.
2. Chipeta J, Banda J, Mbinga M, Wa-Somwe S. Ab sent uvula and thrombocytopenia in an African infant with Job’s syndrome: case report and review of literature. J Infect Dis Immun. 2009;1(1):001-005. http://www.academicjournals.org/JIDI/PDF/Pdf2009/Nov/Chipeta%20et%20al.pdf. Accessed May 2, 2013.
3. Rollnick BR, Kaye CI. Mendelian inheritance of isolated nonsyndromic cleft palate. Am J Med Genet. 1986;24(3):465-473.
4. Richardson GS, Pullen EM. The uvula: its structure and function and its importance. Arch Otolaryngol. 1948;47(4):379-394.
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7. Lowe KR. Severe anemia following uvulectomy in Kenya. Mil Med. 2004;169(9):712.
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11. Grøntved AM, Karup P. Complaints and satisfaction after uvulopalatopharyngoplasty. Acta Otolaryngol Suppl. 2000;543:190-192.
12. Gaafar HA, Gaafar AH, Nour YA. Rhinoscleroma: an updated experience through the last 10 years. Acta Otolaryngol. 2011;131(4):440-446.