Oral Candidiasis Associated with Aging and Salivary Hypofunction in Stomatitis Patients

<b>Objectives:</b> Stomatitis is a broad term for oral mucosal inflammation, and oral candidiasis represents one of its common subtypes caused by fungal infection. This study aimed to investigate the relationship between oral candidiasis and reduced salivary flow in patients diagnosed with stomatitis and to identify clinical predictors of oral candidiasis. <b>Methods:</b> A total of 259 patients (mean age 59.77 ± 15.93 years; range 10-87 years; 201 females) with stomatitis were evaluated for oral candidiasis through <i>Candida albicans</i> culture testing. Clinical characteristics were compared between <i>Candida</i>-positive and <i>Candida</i>-negative groups. Unstimulated salivary flow rate (UFR) and stimulated salivary flow rate (SFR) were measured to assess xerostomia. <b>Results:</b> Among the 259 patients, 81 (31.3%) were diagnosed with oral candidiasis. Patients with candidiasis were significantly older (64.25 ± 14.66 years) than those without (57.73 ± 16.10 years; <i>p</i> = 0.002). Both UFR (0.36 ± 0.32 vs. 0.47 ± 0.28 mL/min, <i>p</i> = 0.006) and SFR (1.21 ± 0.68 vs. 1.41 ± 0.69 mL/min, <i>p</i> = 0.032) were significantly lower in the candidiasis group. The prevalence of xerostomia was significantly higher among <i>Candida</i>-positive patients, based on UFR ≤ 0.2 mL/min (49.4% vs. 18.5%, <i>p</i> < 0.001) and SFR ≤ 0.7 mL/min (27.2% vs. 10.7%, <i>p</i> < 0.001). The predictive accuracy for oral candidiasis was 62.2% based on age (AUC = 0.622; cutoff 64.50 years), 65.8% for UFR (AUC = 0.658; cutoff 0.335 mL/min), and 58.7% for SFR (AUC = 0.587; cutoff 1.150 mL/min). In the generalized linear model, xerostomia, as defined by UFR, was a significant predictor of oral candidiasis (B = 0.328, 95% CI: 0.177-0.480, <i>p</i> < 0.001). <b>Conclusions:</b> Oral candidiasis in patients with stomatitis was more strongly associated with decreased UFR than with aging alone. Among the factors assessed, reduced unstimulated salivary flow may serve as a useful clinical indicator for predicting oral candidiasis, particularly in elderly individuals.