Cutaneous Collagenous Vasculopathy-Associated Benign Pigmented Purpura

A 68-year-old woman presented with an asymptomatic eruption predominantly on the proximal pretibial region of the right lower extremity, which had been present for many months. Her medical history was remarkable for diabetes and hypothyroidism. Physical examination demonstrated "cayenne pepper"-like brown macules, scattered petechiae, and multiple minute, blanching telangiectasias (Figure 1) that were more evident on dermatoscopy (Figure 2). The clinical differential diagnosis included a benign pigmented purpura (BBP; Schamberg type), telangiectasia macularis eruptiva perstans, cutaneous T-cell lymphoma, essential telangiectasia, and cutaneous collagenous vasculopathy (CCV). Results from complete blood cell count, hepatic profile, and serum tryptase were normal. Findings from skin biopsy demonstrated ectatic papillary dermal vessels with hyalinized walls (accentuated by a periodic acid-Schiff stain), a sparse superficial perivascular mononuclear infiltrate, extravasated erythrocytes, and focal siderophages (Figure 3). The diagnosis of CCV with an associated BPP was confirmed.