The pathological spectrum and clinical correlation of pigmented purpuric dermatosis-A retrospective review of 107 cases.

BACKGROUND: Various pathological findings have been reported in pigmented purpuric dermatosis, but their clinical significance remains unclear.

METHODS: We retrospectively reviewed demographics, clinical presentations, pathological patterns and concurrent systemic diseases among biopsy-confirmed cases of pigmented purpuric dermatosis.

RESULTS: A total of 107 cases were ascertained. Five major pathological patterns were identified: lichenoid (45/107, 42.1%), perivascular (40/107, 37.4%), interface (11/107, 10.3%), spongiotic (7/107, 6.5%) and granulomatous (4/107, 3.7%). Lymphocytic vasculitis was present in 17 patients (15.9%), and Langerhans cell microabscess was seen in 4 (3.7%). Nine patients had partial features mimicking mycosis fungoides but none were confirmed. The lichenoid, perivascular and spongiotic patterns correlated to lichen aureus, Schamberg and eczematoid clinical variants, respectively. The interface pattern was associated with a higher risk of coincident autoimmune diseases (18.2%, P = .0280) and gout (27.3%, P = .0180).

CONCLUSIONS: This study described the wide pathological spectrum of pigmented purpuric dermatosis among Asians. Physicians should be aware about the clinical and pathological variations to facilitate diagnosis.