Keratoderma in Systemic Lupus Erythematosus: An Unusual Cutaneous Manifestation of Disease?

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease, with the skin being the second most affected organ after the joints. We present a unique case of a 44-year-old female who presented with an acute flare of SLE and the concurrent onset of keratoderma on both lower limbs. She presented with high-grade fever, arthralgia, and generalized edema of four months duration. A general physical examination revealed pallor and scaly hyperpigmented plaques on both lower limbs, which was confirmed to be keratoderma on histopathological examination. Blood investigations revealed pancytopenia, elevated erythrocyte sedimentation rate (ESR) and C- reactive protein (CRP), and positive titers for anti-nuclear antibody (ANA) and anti-Po ribosomal P proteins (RPP) antibodies. Immunosuppressive medications and topical keratolytics were used to treat her successfully. Post medical management, she showed significant improvement in her symptoms. On follow-up, the patient had a complete resolution of the symptoms and remained well. This case demonstrates keratoderma as a rare incidental finding in a patient with SLE flare. Understanding SLE's various cutaneous manifestations are critical for holistically diagnosing and treating the disease.