Pseudoxanthoma Elasticum
Author: Dr Amy Martinkosky
Chief Editor: Dr Daniel Keith
Pseudoxanthoma elasticum (PXE) is a rare, genetic disorder that results in the progressive calcification of elastic fibers in the skin, eye, and cardiovascular system. Inheritance is autosomal recessive. Mutations in the ABCC6 (MRP6) gene on chromosome 16, which encodes a transmembrane transporter protein, have been shown to cause this condition. Females are more commonly affected than males (2:1). Onset can be as early as five years old with skin papules, or between the ages of 10 and 30 with angioid streaks in the retina, often detected during a routine eye exam. PXE is associated with early cardiovascular disease, therefore it is important to counsel on and optimise other cardiovascular risk factors.
Macroscopic Appearance
The primary skin lesion of PXE is a papule that is somewhat darker than the patient’s natural skin tone. Papules appear yellowish in individuals with Fitzpatrick Skin Types I-III, while in those with Fitzpatrick Skin Types IV-VI, the papules are black. A well-known characteristic of PXE is a “plucked chicken” appearance, usually seen on the lateral aspect of the neck or the flexural creases.
Featured are small, yellow reticulate papules that can be seen on the side of patient’s neck. The papules steadily coalesce to form plaques, and eventually the skin becomes wrinkled, lax, and redundant.
Dermoscopic Appearance
A dermoscopic image of pseudoxanthoma elasticum reveals yellowish strands arranged in a linear pattern, interspersed with linear blood vessels.
Annotated version: Dermoscopic findings includes multiple irregular yellowish areas (black diamonds) alternating with faint reticulated vessels (blue arrows), creating a pseudo network.
Unannotated version for comparison.
Further dermoscopic examples below:
