Necrotizing Infundibular Crystalline Folliculitis: An Unusual Clinical Presentation and Demonstration of the Presence of Calcium Palmitate.

Necrotizing infundibular crystalline folliculitis (NICF) is a rare disorder, which was described for the first time by Lucke et al in 1999. NICF is characterized by multiple folliculocentric papules with a predilection for occurring in seborrheic areas in adults and corresponding dilated follicular ostia containing crystalline material. The precise pathogenesis and nature of this crystalline material are currently unknown. Here, we report an unusual case of NICF presented as an uncommon generalized skin rash in an adolescent. In addition, we present analysis using infrared microscopy for improved characterization of this crystalline material. Similar to previous cases, a biopsy revealed a dilated follicular ostium with the appearance of containing crystalline material associated with parakeratosis. Infrared microscopy analysis produced specific spectral features of calcium palmitate.