Necrotizing infundibular crystalline folliculitis

We describe a 22-year-old woman with a background of acne who developed mul tiple folliculocentric facial papules associated with sharply demarcated wa xy, keratotic plugs. Multiple skin biopsies showed umbilicated craters that were filled with dispersed bundles of eosinophilic filaments embedded in a pale amorphous matrix forming a plug. The plugs bulged into the upper derm is. Serial sections showed vacuolar and filamentous destruction of the infu ndibular and adjacent perifollicular epithelium and a close relationship of the crystalline necrosis to follicles. Electron microscopy revealed that t he filamentous bundles were tonofilaments. No fresh material was available for polarization and the paraffin sections failed to polarize. The clinical and pathological findings of the lesions in our patient were identical to those reported as a new perforating disorder with urate-like crystals. Our case indicates that the process may represent crystalline folliculocentric necrosis rather than a primary perforating disorder. The nature and basis o f the crystals that have a urate-like appearance remain to be determined.