Microscopic examination of the biopsy specimen revealed damage of the small vessels of the upper dermis. A neutrophilic infiltrate was found in the vessel walls and focally in the interstitium. The results of routine blood tests and urinalysis were within normal limits except for a transient elevation of alanine aminotransferase and alkaline phosphatase levels. The results of laboratory tests for the following components were negative or normal: serum antibodies for hepatitis B and C, cytomegalovirus, Epstein-Barr virus, mycoplasma, anti–streptolysin O, rheumatoid factor, antinuclear antibody, and complements C3 and C4. The eruption resolved after 1 week of oral prednisone therapy at a dosage of 40 mg/d.
Purpuric Edematous Lesions. Arch Dermatol. 1999;135(11):1409-b-1414. doi:10-1001/pubs.Arch Dermatol.-ISSN-0003-987x-135-11-dof9021