Misdiagnosis of Oral Candidiasis in Primary Care: Erosive Oral Lichen Planus in a Young Patient

Abstract

Oral candidiasis is one of the most common fungal infections, and its diagnosis is typically clinical; however, misinterpretation may lead to confusion with other conditions that share similar features, such as oral lichen planus (OLP), a chronic immune-mediated inflammatory disease. The aim of this study is to describe a case of erosive OLP initially treated as candidiasis, emphasizing the importance of differential diagnosis in persistent ulcerative lesions. A 19-year-old male presented with multiple painful diffuse erosions and ulcerations that interfered with speech and eating, with a pain intensity of 10/10 on the visual analog scale. He was initially diagnosed with oral candidiasis in primary care and treated with nystatin without improvement. Clinical examination revealed bilateral involvement of the buccal and labial mucosa with erosive and ulcerative lesions, along with reticular whitish plaques consistent with Wickham’s striae and a negative Nikolsky sign. A clinical diagnosis of erosive OLP was established and later confirmed by histopathological analysis. Treatment with systemic corticosteroids, with gradual tapering and nighttime nystatin as antifungal prophylaxis, was initiated, resulting in complete clinical resolution within one month and stable evolution over two years, with mild episodes associated with trauma or stress. Accurate differential diagnosis of oral lesions is essential for timely management. Erythematous or ulcerative oral lesions that do not respond to antifungal therapy should be reassessed, and OLP should be considered in the differential diagnosis. Biopsy and clinicopathological correlation are key to avoiding misdiagnosis and unnecessary treatments.