A 30-year-old woman comes to the office due to a facial rash for the past 3 weeks. The rash worsens with sun exposure, and she has tried several topical sunscreens without relief. The patient also reports easy fatigability and occasional pain and swelling of her hand joints. Past medical history is notable for mild cervical dysplasia that was diagnosed at age 21 and resolved spontaneously. The patient does not use tobacco, alcohol or illicit drugs. Blood pressure is 140/85 mm Hg and pulse is 78/min. Physical examination reveals mucosal pallor, a superficial ulcer on the hard palate, and a rash as shown in the image below. Cardiopulmonary and abdominal examinations are normal. Which of the following laboratory findings is most likely to be seen in this patient's condition?

Question

A 30-year-old woman comes to the office due to a facial rash for the past 3 weeks.  The rash worsens with sun exposure, and she has tried several topical sunscreens without relief.  The patient also reports easy fatigability and occasional pain and swelling of her hand joints.  Past medical history is notable for mild cervical dysplasia that was diagnosed at age 21 and resolved spontaneously.  The patient does not use tobacco, alcohol or illicit drugs.  Blood pressure is 140/85 mm Hg and pulse is 78/min.  Physical examination reveals mucosal pallor, a superficial ulcer on the hard palate, and a rash as shown in the image below.  Cardiopulmonary and abdominal examinations are normal.  Which of the following laboratory findings is most likely to be seen in this patient's condition?

Quizplus · Accepted Answer

11ec160b_3a6b_8921_9249_0b5b64ded98f_MD0001_00 This patient has a photosensitive rash in the classic "butterfly" distribution at the malar region of the face, associated with inflammatory arthritis, and an ulcer at the hard palate. This constellation of clinical features is typical for new-onset systemic lupus erythematosus (SLE). The central disturbance in SLE is excessive autoantibody production due to loss of self-tolerance. Autoantibodies directed against nuclear components (anti-nuclear antibodies) are the most characteristic feature of SLE. Autoantibody binding to self-antigens leads to the formation of circulating immune complexes that deposit in various organs and cause complement activation. Active SLE is therefore characterized by consumption of complement with reduced serum complement levels. (Choice B) Anti-cyclic citrullinated peptide antibodies are associated with rheumatoid arthritis (RA). RA causes an inflammatory arthritis, primarily affecting the small joints of the hands and wrists. Cutaneous manifestations of RA include subcutaneous nodules and leg ulcers, but a malar rash is more consistent with SLE. (Choice C) Anti-mitochondrial antibodies are typically found in primary biliary cirrhosis, which typically presents with cholestatic symptoms (eg, pruritus, jaundice, malabsorption). (Choice D) Disseminated gonococcal infection is characterized by fever, migratory polyarthritis, and skin lesions. The lesions are typically scattered pustules on the arms and legs and not a malar rash. (Choice E) Human leukocyte antigen (HLA)-B27 is seen with increased frequency in the seronegative spondyloarthropathies (eg, ankylosing spondylitis, reactive arthritis, arthritis associated with inflammatory bowel disease, psoriatic arthritis). Educational objectives: Systemic lupus erythematosus is characterized by loss of immune self-tolerance with production of autoantibodies against nuclear antigens. Binding of autoantibodies to self antigens leads to deposition of immune complexes in tissues and consumption of complement. __________ References: The pathogenesis of systemic lupus erythematosus-an update. (http://www.ncbi.nlm.nih.gov/pubmed/23131610) Linking complement and anti-dsDNA antibodies in the pathogenesis of systemic lupus erythematosus. (http://www.ncbi.nlm.nih.gov/pubmed/22941560)

A 30-Year-Old Woman Comes to the Office Due to a Facial