29th April 2024

A 28-year-old woman presents with joint pain and swelling in her wrists and knees, a malar rash across her cheeks and nose, and intermittent sores in her mouth.

A 28-year-old woman presents with joint pain and swelling in her wrists and knees, a malar rash across her cheeks and nose, and intermittent sores in her mouth. She also reports experiencing extreme fatigue and recent hair loss. She has a history of photosensitivity and a previous miscarriage. On examination, there is tenderness and swelling in her wrists and knees, and the malar rash is evident. She has no Heberden’s nodes.

Investigations:

Haemoglobin: 110 g/L (115–150)

White cell count: 3.2 × 10^9/L (4.0–11.0)

Platelets: 120 × 10^9/L (150–400)

ANA (antinuclear antibodies): Positive

Anti-dsDNA antibodies: Positive

CRP: 30 mg/L (<5)

Complement levels: Decreased

Which is the most likely diagnosis?