Unilateral Papulopustular Dermatosis: Demodex Mites Bridging Rosacea and Demodicosis.

Papulopustular rosacea (PPR) is a common inflammatory dermatosis often associated with Demodex mite proliferation, though its pathogenesis remains incompletely understood. While bilateral presentations predominate, unilateral cases are rare and may offer unique insights into disease mechanisms. We report a case of a 68-year-old female with a chronic erythematous and scaly rash confined to the right malar region. Standardized skin surface biopsy revealed a high Demodex density (>5 mites/cm²), confirming demodicosis. Treatment with topical ivermectin cream resulted in significant improvement within four weeks. This case underscores the importance of considering demodicosis in the differential diagnosis of atypical facial dermatoses and revisits the classification, pathogenesis, diagnostic algorithm, and treatment strategies for inflammatory facial conditions. The findings support the inclusion of Demodex proliferation in disease frameworks and its potential impact on tailored therapeutic approaches.