Uraemic stomatitis is a very rare oral mucosal disorder possibly because nowadays patients are seldom left without dialysis at advanced and prolonged stages of renal failure. The present report details the features of uraemic stomatitis in a patient with longstanding chronic renal failure.
A 46-year-old male was referred by the nephrology department of Hospital das Clinicas to the oral medicine unit of UFPE, Recife, Brazil, complaining of a burning sensation of the oral mucosa and dysgeusia. The patient had developed chronic renal disease due to non-specific nephritis associated with severe hypertension in 1991, at which time he commenced haemodialysis. In the same year the patient underwent renal transplantation but the renal allograft was rejected 4 years later. The patient continued haemodialysis for 10 years until he underwent a further renal transplant in 2001. Perhaps surprisingly, at the time of referral his renal disease was considered stable, aside from elevation of plasma urea (288 mg/ml: normal range 1821 mg/ml) and creatinine. Unfortunately, no details of calcium, phosphate or haemoglobin were available at that time. Intra-oral examination revealed adherent white plaques of the floor of the mouth, bolcal mucosae, lateral borders of the tongue and gingivae. To establish the precise diagnosis, incisional biopsies of the tongue were undertaken. Histopathogical examination revealed an epithelium markedly acanthotic, with most of the suprabasal layers comprising pale staining degenerate keratinocytes. The surface layers showed sloughing, and there was hyperplasia of the basal cell component. Fungal stains, immunohistochemistry for human papillomavirus (HPV) and EpsteinBarr virus (EBV) late membrane protein, and in situ hybridization for EBV early RNA were all negative. Based upon the clinical and histopathological features a final diagnosis of uraemic stomatitis seemed appropriate.
Uraemic stomatitis has been suggested to arise when blood urea levels are more than 300 mg/ml [1], although there have been reports of mucosal changes at urea levels of <200 mg/ml [2,3]. Patients with uraemia may have dysgeusia and an altered perception to sweet and sour taste [4], and a burning sensation of the lips and tongue possibly caused by pain pathway activation [5]. Younger patients usually have more significant impairment in taste modalities, but may have a better recovery of neural taste function following dialysis [6]. Zinc deficiency can arise in renal failure [7], however, there is no evidence that mild zinc deficiency gives rise to oral mucosal changes nor oral pain.
Uraemic stomatitis responds to treatment of underlying renal failure. The present patient had resolution of oral mucosal lesions and symptoms following hydrogen peroxide therapy. This response perhaps reflects an antimicrobial effect thus reducing the local levels of bacterially derived ureases. The aetiology of this oral disorder is unclear; however, as transplant failure is an increasingly frequent condition, the reappearance of such lesions may be expected.
1 Departamento de Clínica e Odontologia Preventiva2 Especializacao em Estomatologia Universidade Federal de Pernambuco Av. Prof. Moraes Rego 1235, Recife, PE, 50670901 Brazil3 Oral Medicine Division of Maxillofacial Diagnostic, Medical and Surgical Sciences Eastman Dental Institute for Oral Health Care Sciences University of London 256, Gray's Inn Road London WC1X 8LD UK
Acknowledgments
J.C.L. is partially funded by a grant from CNPq (Ministry of Science and Technology, Brazil).
References