A 42-year-old woman comes to the office due to a rash. She has experienced recurring "red spots" on her legs for 2-3 years. These appear sporadically, last a few weeks to a few months, and disappear spontaneously. The rash is not pruritic. When it occurs, the patient also experiences generalized fatigue and arthralgias involving her hips and knees. She rarely has right lower quadrant pain with the rash. Review of systems is otherwise normal.
Medical history is unremarkable. The patient has no known drug allergies. Her only medication is an oral contraceptive, which she has taken for several years. She does not use tobacco, alcohol, or illicit drugs. She is single and works in an office.
On examination, the patient appears healthy. Blood pressure is 136/86 mm Hg, pulse is 72/min, and respirations are 14/min. BMI is 24 kg/m². Physical examination is normal except for the skin. A total of 10-12 palpable red lesions, measuring 1×0.5 cm, are scattered over both lower extremities distal to the mid-calf. The lesions are nontender and do not blanch with pressure.
Laboratory results are as follows:
Which of the following would most likely be found in this patient?

Question

A 42-year-old woman comes to the office due to a rash. She has experienced recurring "red spots" on her legs for 2-3 years. These appear sporadically, last a few weeks to a few months, and disappear spontaneously. The rash is not pruritic. When it occurs, the patient also experiences generalized fatigue and arthralgias involving her hips and knees. She rarely has right lower quadrant pain with the rash. Review of systems is otherwise normal.
Medical history is unremarkable. The patient has no known drug allergies. Her only medication is an oral contraceptive, which she has taken for several years. She does not use tobacco, alcohol, or illicit drugs. She is single and works in an office.
On examination, the patient appears healthy. Blood pressure is 136/86 mm Hg, pulse is 72/min, and respirations are 14/min. BMI is 24 kg/m². Physical examination is normal except for the skin. A total of 10-12 palpable red lesions, measuring 1×0.5 cm, are scattered over both lower extremities distal to the mid-calf. The lesions are nontender and do not blanch with pressure.
Laboratory results are as follows:

Which of the following would most likely be found in this patient?

Quizplus · Accepted Answer

11ec193a_98ee_ff9e_853d_4bf58630209d_MD0002_00 This patient likely has Henoch-Schönlein purpura (HSP); although often thought to be a childhood disorder, HSP and its recurrent forms are also seen in adults. It classically presents with the tetrad of palpable purpura (multiple raised, erythematous, nonblanching lesions on the lower extremities), abdominal pain, arthritis, and renal involvement in the form of glomerulonephritis; however, many patients do not have the full tetrad. The disease is a leukocytoclastic vasculitis characterized on skin biopsy by prominent IgA-immune complex deposition in small vessels. IgA deposits also affect the mesangium, resulting in a wide spectrum of renal dysfunction ranging from asymptomatic hematuria to nephrotic syndrome with acute kidney injury. Adults are much more likely than children to experience progressive renal decline. Treatment is mainly supportive; however, glucocorticoids are used in patients with severe renal disease (eg, >750 mg/day of proteinuria, nephrotic syndrome). (Choice A) Anti-double-stranded DNA antibodies are specific for systemic lupus erythematosus. Although this condition often involves the joints and kidneys, it is typically associated with a malar or discoid rash (eg, scarring erythematous plaque with scale) rather than palpable purpura. (Choice B) Mixed cryoglobulinemia syndrome is associated with hepatitis C infection in up to 95% of cases. The vasculitis presents like that of HSP, with palpable purpura, renal disease, and arthralgias; however, peripheral neuropathy is often present, and abdominal pain is less common and typically less prominent. In addition, hepatitis C infection is unlikely in this patient who was born after 1965 and has no intravenous drug use or blood transfusion history. (Choice C) Anti-Ro antibodies commonly occur in Sjögren syndrome, which is rarely associated with palpable purpura. However, these patients characteristically have sicca symptoms (dry eyes and mouth, parotid gland enlargement), and abdominal pain and renal dysfunction are not typical. (Choice E) Kidney biopsy in HSP usually demonstrates mesangiocapillary glomerulonephritis with prominent deposition of IgA. Focal glomerular sclerosis can occur in many contexts (eg, HIV, lupus nephritis, heroin use) but is less common in HSP. Educational objective: Henoch-Schönlein purpura is a systemic vasculitis characterized by IgA-immune complex deposition in small vessels and the renal mesangium. It is most common in children but can present in adults and should be suspected in patients with some combination of palpable purpura, abdominal pain, arthritis, and renal dysfunction. __________

A 42-Year-Old Woman Comes to the Office Due to a Rash