Rosacea overlapping the malar rash: A diagnostic challenge in early systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with heterogeneous manifestations, often overlapping with other conditions and complicating diagnosis. Oral lesions, though less common than cutaneous involvement, may offer important diagnostic clues. We report a 51-year-old female with rosacea, who developed persistent oral ulcers initially linked to a dental prosthesis. Lesions worsened despite adjustments and corticosteroid therapy, and the first biopsy was inconclusive. A second biopsy showed features of lupus erythematosus, including basal layer degeneration, subepithelial lymphocytic infiltrate, and PAS-positive basement membrane thickening. Serology revealed low-titter ANA (1:160) without additional autoantibodies. The coexistence of rosacea and lupus-like lesions delayed diagnosis, highlighting the need for clinicopathological correlation. Over 2 years of multidisciplinary follow-up, the patient achieved remission of oral and cutaneous lesions despite persistently low ANA titters. This case underscores the diagnostic complexity of overlapping dermatologic conditions and reinforces the importance of interdisciplinary management and long-term follow-up in suspected SLE.