Pseudoxanthoma elasticum-like fibers in the inflamed skin of patients without pseudoxanthoma elasticum

Background: Pseudoxanthoma elasticum (PXE) is an inherited disorder leading to characteristic calcified elastic fibers in skin, eyes and vasculature. PXE-like fibers have not been described in inflammatory skin disease in the absence of other signs of PXE. Methods: The histopathology of inflamed skin from 13 patients that contained PXE-like fibers but lacked clinical evidence of PXE were studied. Six of these and six comparison specimens from known patients with PXE were subjected to polymerase chain reaction amplification and sequencing of exons 24 and 28 of the PXE-associated gene ABCC6. This genetic analysis employed a novel assay utilizing paraffin-embedded tissue. Results: Incidental PXE-like fibers were found in patients without clinical suspicion of PXE in lesional tissue showing lipodermatosclerosis, granuloma annulare, lichen sclerosus, morphea profunda, erythema nodosum, septal panniculitis, basal cell carcinoma and fibrosing dermatitis. Two patients with PXE-like fibers but without clinical findings of PXE were heterozygous for a PXE-associated ABCC6 sequence alteration. Conclusions: This pilot study shows elastic fibers similar to those of PXE in the lesional skin of patients with a variety of inflammatory skin diseases in the absence of clinical evidence of PXE; and some of these patients harbor changes in ABCC6. Bowen AR, Gotting C, LeBoit PE, McCalmont TH. Pseudoxanthoma elasticum-like fibers in the inflamed skin of patients without pseudoxanthoma elasticum.