Case Report: Uremic stomatitis revealing undiagnosed kidney failure in an adolescent with PAX2-related nephropathy

Background Uremic stomatitis is a rare oral mucosal disorder associated with kidney failure in adults. It is exceptionally uncommon in children. Its clinical presentation may mimic more common conditions, such as oral candidiasis or traumatic keratosis, potentially delaying recognition of the underlying systemic disease. To our knowledge, this appears to be the first reported pediatric case of uremic stomatitis associated with PAX2-related nephropathy. Case presentation A 15-year-old female patient was referred for persistent multifocal white lesions of the oral mucosa. Intraoral examination revealed pseudomembranous and hyperkeratotic whitish plaques involving the right buccal mucosa, labial commissure, floor of the mouth, and the ventral and lateral surfaces of the tongue, with partially removable areas associated with underlying erythema and superficial erosions. The lesions showed only partial improvement following topical antifungal and antiseptic therapy. Their persistence, diffuse distribution, and the presence of marked mucosal pallor prompted further laboratory investigations. Blood tests revealed severe anemia (hemoglobin 5.4 g/dL), elevated serum urea (106 mg/dL), serum creatinine of approximately 13 mg/dL, severely reduced estimated glomerular filtration rate (approximately 3.7 mL/min/1.73 m 2 ), and hypocalcemia. The patient was urgently referred to Pediatric Nephrology and diagnosed with kidney failure, subsequently attributed to PAX2-related nephropathy. Renal replacement therapy with hemodialysis was initiated, followed by progressive regression of the oral lesions. The patient later underwent kidney transplantation with favorable early graft recovery. Conclusion This case highlights uremic stomatitis as a rare but clinically significant oral manifestation of kidney failure also in children and emphasizes the importance of considering systemic disorders in the differential diagnosis of persistent multifocal white oral lesions. In particular, lesions associated with mucosal pallor and poor response to conventional therapy should prompt laboratory investigations, including renal function assessment. This report further underscores the important role of oral medicine specialists in the early recognition of occult systemic disease and timely referral for multidisciplinary management.