Association between Inhaled Corticosteroid Use, Salivary pH Alterations and Oral Lichen Planus and Oral Lichenoid Lesions in Bronchial Asthma Patients: A Case–control Study

Abstract Background: Inhaled corticosteroids (ICS) are standard therapy for asthma but often cause oral mucosal alterations. These effects arise from reduced salivary flow, pH imbalance, and local immune disruption, which may contribute to asymptomatic oral lichenoid lesions in long-term users. Aim: To determine the association between ICS use, salivary pH, and asymptomatic oral lichen planus (OLP) and oral lichenoid reaction (OLR) in asthma patients. Materials and Methods: This cross-sectional, case–control study assessed the association between ICS therapy, salivary pH, and asymptomatic OLP/OLR in adults with asthma and non-asthmatic controls. Participants aged 18–70 years provided consent. Exclusions covered systemic illness and oral pathology. Data were analyzed using the t -test, Chi-square test, and one-way analysis of variance. Results: Thirty-seven patients had oral lesions (28 OLP, 9 OLR). Lower salivary pH was strongly associated with reticular-type lesions ( P = 0.00), and higher ICS doses correlated with reduced salivary pH ( r = −0.247, P = 0.003). Asthma severity and gender did not significantly affect lesion development. Conclusion: Long-term ICS therapy reduces salivary pH and increases the risk of asymptomatic OLP/OLR. Regular oral examinations are recommended for patients on ICS.