Bacterial endocarditis results from the seeding of bacterial emboli primarily from the mitral or tricuspid valves.4 Streptococci are the primary infectious agent, with staphylococci being more common among intravenous drug users. High-risk populations include patients with artificial valves, the elderly, and the immunocompromised.4
Clinical manifestations include Janeway lesions (asymptomatic hemorrhagic papules on the palms) and Osler’s nodes (tender nodules on the fingertips). Splinter hemorrhages, or linear nonblanching lesions, may be present within the nail beds. Palpable purpura and petechiae may also be found.
Patients may have positive blood cultures, leukocytosis, an elevated ESR, or vegetations on a transesophageal echocardiogram.4 The physical exam may reveal a new cardiac murmur.
High circulating levels of cryoglobulins can arise in the setting of hepatitis C infection, but can also be seen in a number of autoimmune disorders and other infectious diseases.5 Cryoglobulins are immune complexes that are deposited into the lumen of microvasculature. In cold temperatures, these cryoglobulins precipitate, resulting in vasculitis. While most patients are asymptomatic, cutaneous findings in the distal extremities can include palpable purpura, ulcerations, and livido reticularis.5 Patients may complain of arthritis or symptoms consistent with Raynaud’s phenomenon.
Detection of specific serum cryoprecipitates isolated by immunofixation is pathognomonic for this condition, provided the sample is collected in a warm tube. Elevated rheumatoid factor and decreased complement levels may also be seen.5
Henoch-Schönlein purpura (HSP) is a small vessel vasculitis caused by IgA deposition that predominantly affects children. HSP has a host of systemic symptoms, often preceded by a benign upper respiratory infection, consisting of palpable purpura, arthritis, abdominal pain, and glomerulonephritis.6 Palpable purpura will generally be found in dependent portions of the body—especially the buttocks and lower legs.