A case of pseudoxantoma elasticum

Abstract

Pseudoxanthoma elasticum (PXE) is a rare, genetic, multisystem connective tissue disorder primarily affecting the skin, eyes, and the cardiovascular system (CVS) [1,2]. PXE is characterized by progressive pathologic calcification and fragmentation of the elastic tissue in the affected organs. PXE appears to be present in all over the world's populations. In different reports, the prevalence is given to range between 1:25,000 and 1:100,000 [3]. Due to lack of adequate knowledge among patients and physicians, delay in diagnosis, and genetic heterogeneity, the exact prevalence of PXE might be underestimated. Although autosomal recessive inheritance patterns have mainly been reported, some families show autosomal dominant inheritance and some cases are sporadic without family history [4]. In most cases, the skin is the first organ system affected. Skin changes are usually detected in the second or third decade [5]. The affected skin eventually becomes lax, redundant, and inelastic. PXE also affects ocular fundus due to pathologic changes in Bruch's membrane. Early ocular findings are pigment irregularities of the temporal fundus called "Peau d' orange", angioid streaks due to breaks of Bruch's membrane and later choroidal neovascularisation and disciform scars [1]. CVS manifestations of PXE include arterial hypertension, peripheral arterial disease, angina pectoris, restrictive cardiomyopathy, mitral valve prolapse, and sudden cardiac death [3,6].A 61-year-old female patient was referred to our dermatology outpatient clinic by the ophthalmology clinic because of angioid streaks detected on fundus examination. Patient did not have any subjective complaints. She had had history of diabetes for 11 years and coronary artery disease for 10 years. On dermatologic examination, we detected yellow cobblestone like lesions with lax, redundant, and inelastic skin over the anterior and lateral parts of the neck and axilla (Fig. 1). She had not consulted any dermatologist before because of these lesions.Patient had applied to the ophthalmology outpatient clinic because of visual impairment. Best corrected visual acuities were 0.2/0.2 and intraocular pressures were 15/15 mmHg respectively for the right and left eyes. Anterior segments were normal. Fundoscopy revealed bilateral angioid streaks originating from the optic disk, radiating outwards especially under the macula as grayish-brownish irregular lines (Figs. 2 and 3). Optical coherence tomography examination revealed increased reflectivity at the level of retinal pigment epithelium-Bruch's membrane-choroid complex. Biopsy taken from the affected skin showed calcified and fragmented elastic fibers in the middle and lower dermis and confirmed the diagnosis. PXE is a rare connective tissue disorder leading to a broad range of complications including mainly the skin, eyes, and CVS [1]. Clinical findings are due to pathologic calcification and fragmentation of elastic tissue in the dermis of the skin, Bruch's membrane of the retina, and intima of the vascular arteries [5]. These...