Lower Extremity Petechiae and Purpura
Am Fam Physician. 2020 May 1;101(9):567-568.
A 40-year-old man presented with a 10-day history of a worsening rash that began on his legs and advanced to his lower abdomen. The rash was red and nonpruritic. The patient also had muscle aches, mild abdominal discomfort, and a recent sore throat. His medical history included diabetes mellitus, hypertension, and cirrhosis due to non-alcoholic steatohepatitis. His long-term medications were insulin degludec (Tresiba), semaglutide, and lisinopril.
Physical examination revealed a nontender, symmetrical, petechial, and purpuric rash from the soles of the feet to the lower abdomen (Figures 1 and 2). His physical examination was otherwise unremarkable, including normal vital signs. His platelet count was low at 110 × 103 per μL (110 × 109 per L), but findings on a complete blood count and basic metabolic panel were otherwise normal. Urinalysis revealed 10 to 25 red blood cells per high-power field without protein. Recent laboratory tests were negative for hepatitis.
Based on the patient's history and physical examination findings, which one of the following is the most likely diagnosis?
A. Antineutrophil cytoplasmic autoantibody (ANCA)–associated vasculitis.
B. Cryoglobulinemia vasculitis.
C. Drug-induced leukocytoclastic vasculitis.
D. Immune thrombocytopenic purpura.
E. Immunoglobulin A (IgA) vasculitis.
The answer is E: IgA vasculitis. IgA vasculitis, formerly known as Henoch-Schönlein purpura, is a systemic small-vessel vasculitis characterized by deposition of immune complexes containing IgA. Approximately 90% of cases occur in children four to seven years of age, but it rarely occurs in older age groups and can be more severe in adults.1 The purpuric rash, a hallmark of a small-vessel leukocytoclastic vasculitis, is commonly accompanied by arthralgias and abdominal pain. IgA vasculitis is often preceded by an infection, such as an upper respiratory tract infection. Kidney involvement is common, manifesting as hematuria or proteinuria.
Skin biopsy can confirm the diagnosis. Deposition of IgA in dermal vessels confirms the diagnosis and rules out other causes of leukocytoclastic vasculitis. IgA vasculitis often resolves in one to two months without treatment. Acetaminophen or nonsteroidal anti-inflammatory drugs can be used to relieve
Referencesshow all references
1. Audemard-Verger A, Pillebout E, Guillevin L, et al. IgA vasculitis (Henoch-Shönlein purpura) in adults: diagnostic and therapeutic aspects. Autoimmun Rev. 2015;14(7):579–585....
2. Geetha D, Jefferson JA. ANCA-associated vasculitis: core curriculum 2020. Am J Kidney Dis. 2020;75(1):124–137.
3. Cacoub P, Comarmond C, Domont F, et al. Cryoglobulinemia vasculitis. Am J Med. 2015;128(9):950–955.
4. Grau RG. Drug-induced vasculitis: new insights and a changing lineup of suspects. Curr Rheumatol Rep. 2015;17(12):71.
5. Neunert C, Lim W, Crowther M, et al. The American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia. Blood. 2011;117(16):4190–4207.
This series is coordinated by John E. Delzell Jr., MD, MSPH, associate medical editor.
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