Multimorbidity Burden and Specific Clinical Comorbidities in Onychomycosis: A Retrospective Case-Control Study in an Indonesian Tertiary Referral Hospital

Abstract

Background: Onychomycosis is the most common chronic fungal disease of the nail unit worldwide. Metabolic, vascular and cutaneous disorders are known risk factors. The added effect of a combined comorbidity burden in tropical outpatient populations remains under-evaluated.

Objective: To describe the spectrum of clinical comorbidities and to analyze the association between cumulative comorbidity burden and onychomycosis among outpatients of a tertiary referral hospital in Indonesia.

Methods: This retrospective case-control study took place at the Dermatology Clinic of Dr. Moewardi General Hospital, Surakarta (January 2020 to June 2026). It enrolled 76 patients. There were 38 mycologically confirmed onychomycosis cases (positive 10% potassium hydroxide mount and/or culture) and 38 outpatient controls without onychomycosis. We recorded demographics, obesity, diabetes mellitus, hypertension, venous insufficiency, psoriasis, HIV/immunosuppression, systemic autoimmune disease, tinea pedis and the total comorbidity count. Bivariate analyses used the chi-square and Fisher exact tests. We calculated odds ratios (OR) with 95% confidence intervals (CI).

Results: Tinea pedis (47.4%), obesity (39.5%), hypertension (36.8%), autoimmune disease (31.6%) and diabetes mellitus (31.6%) were the most common comorbidities among cases. Multimorbidity (≥2 comorbidities) was more frequent in cases than in controls (50.0% vs. 15.8%). Patients with no comorbidity were mostly controls (28.9% vs. 7.9%). Cumulative comorbidity burden was associated with onychomycosis (chi-square = 12.01, p = 0.002). The OR for ≥2 vs. 0 comorbidities was 11.61 (95% CI: 2.41–55.94, p = 0.002).

Conclusion: A higher cumulative comorbidity burden was associated with onychomycosis in this single-center case-control study. Management should address coexisting metabolic, vascular and fungal-reservoir conditions alongside antifungal treatment.