Pseudoxanthoma elasticum is a rare inherited disorder that gradually transforms the body’s elastic tissues, leaving visible marks on the skin, changes deep within the eyes, and silent effects on blood vessels that may only reveal themselves years after the first signs appear.

Epidemiology

Pseudoxanthoma elasticum affects a relatively small number of people worldwide, though exact figures remain uncertain. Current estimates suggest the condition occurs in somewhere between 1 in 25,000 to 1 in 100,000 individuals in the general population, making it a genuinely rare disease that many doctors may only encounter once or twice in their careers^[1][3]. This range of estimates reflects the reality that many mild cases likely go undiagnosed, particularly when symptoms are subtle or when healthcare providers are unfamiliar with the condition’s varied presentation.

The distribution of this condition shows some interesting patterns across different groups. Women appear to be diagnosed with pseudoxanthoma elasticum roughly twice as often as men, though researchers have not yet determined why this gender difference exists^[3][5]. The condition does not favor any particular ethnic group and has been documented across all races and ethnicities around the world^[8]. While the skin changes often begin during childhood or adolescence, the average age at which people receive a formal diagnosis falls between 30 and 40 years, suggesting a significant delay between when symptoms first appear and when the condition is actually recognized^[3][15].

This delay in diagnosis, which can extend nine years or more on average, creates challenges for patients who may spend years wondering about unusual skin changes or vision problems before receiving answers^[6]. The relatively low awareness of pseudoxanthoma elasticum among healthcare providers contributes to this gap, as the condition’s rarity means many clinicians have never encountered it during their training or practice.

Causes

Pseudoxanthoma elasticum stems from changes in genetic instructions that affect how the body manages certain chemical processes. The condition is caused by mutations in a gene called ABCC6, which provides the blueprint for creating a protein that functions as a transporter within cells^[1][3]. This protein, known as MRP6 or ABCC6 protein, is primarily produced in the liver and kidneys, though it appears in smaller amounts in other tissues throughout the body, including the skin, stomach, blood vessels, and eyes.

The ABCC6 protein’s normal job involves moving substances across cell membranes, though scientists are still working to identify exactly what these substances are. Current research suggests the protein plays a crucial role in releasing or transporting molecules that help control how calcium and other minerals are deposited in tissues^[1]. When the ABCC6 gene contains mutations, the resulting protein either doesn’t work properly or isn’t produced at all. This malfunction appears to reduce levels of inorganic pyrophosphate (PPi) circulating in the blood, a compound that normally acts as a powerful brake on unwanted mineral deposits^[3][10].

Scientists have identified more than 300 different mutations in the ABCC6 gene that can cause pseudoxanthoma elasticum, with two common variants accounting for roughly half of all cases^[3][6]. The diversity of mutations helps explain why the condition’s severity and specific symptoms can vary considerably from one person to another, even within the same family. Understanding these genetic foundations has transformed pseudoxanthoma elasticum from a mysterious skin condition into a recognized metabolic disorder, though many questions about the precise mechanisms remain unanswered.

Risk Factors

The primary risk factor for developing pseudoxanthoma elasticum is inheriting specific genetic mutations from both parents. The condition follows an autosomal recessive inheritance pattern, meaning a person must receive one mutated copy of the ABCC6 gene from each parent to develop the disease^[1][2]. Parents who each carry one mutated gene typically show no symptoms themselves but have a 25% chance with each pregnancy of having a child who inherits both mutated copies and develops pseudoxanthoma elasticum. There is a 50% chance their child will be a carrier like them, and a 25% chance the child will inherit two normal gene copies.

Based on the condition’s prevalence, researchers estimate that between 0.63% and 1.26% of the general population carries one mutated copy of the ABCC6 gene without knowing it^[3]. These carriers remain healthy throughout their lives but can pass the mutation to their children. In rare situations, the inheritance pattern can appear confusing, such as when one parent has obvious symptoms while the other appears unaffected, yet both have children with the condition. In these cases, the seemingly unaffected parent actually carries mutations but has such mild symptoms that they went unnoticed^[1].

Beyond the genetic foundation, certain lifestyle factors and health conditions can worsen the complications of pseudoxanthoma elasticum once the disease is present. Smoking, for instance, amplifies cardiovascular problems because of its effects on blood vessels that are already compromised by mineral deposits^[2][4]. Obesity, high blood pressure, and elevated cholesterol levels represent additional risk factors that accelerate damage to blood vessels affected by the condition. These factors don’t cause pseudoxanthoma elasticum but can significantly influence how severely the disease affects an individual’s health and quality of life.

Symptoms

The visible signs of pseudoxanthoma elasticum typically appear first on the skin, often during childhood or the teenage years, though they may go unnoticed initially. Small yellowish bumps called papules emerge on the skin, measuring between 1 and 5 millimeters across and often appearing on the sides and back of the neck first^[3][7]. These papules also commonly develop in areas where skin naturally folds and bends, such as the armpits, the inner surfaces of the elbows, the groin, and behind the knees. The lesions themselves cause no pain or itching, which partly explains why people may not seek medical attention for them early on.

As time passes, these individual papules tend to merge together, creating larger patches that give the affected skin a distinctive “cobblestone” or “plucked chicken” appearance^[3][8]. The skin in these areas gradually becomes softer, looser, and slightly wrinkled. Some people develop prominent horizontal creases across their chin, a feature that can appear relatively early in adulthood. Though less common, the yellowish papules can also appear on mucous membranes inside the mouth, particularly on the inner aspect of the lower lip, as well as in the vaginal or rectal areas.

The eyes develop their own characteristic changes, though these initially cause no symptoms that patients would notice. An eye examination may reveal a mottled appearance of the retina that doctors call peau d’orange, a French term meaning “skin of an orange,” which typically appears during the first two decades of life^[3][8]. More distinctive are angioid streaks, which are narrow, irregular lines that radiate outward from the optic nerve at the back of the eye, resembling blood vessels but actually representing cracks in a layer of tissue called Bruch’s membrane^[2][5]. These angioid streaks develop in nearly all adults with pseudoxanthoma elasticum and sometimes appear even in childhood or adolescence.

Cardiovascular symptoms typically emerge later than skin and eye changes, though they can be the most concerning manifestations of the condition. People may develop a cramping pain in their legs during walking or exercise, a symptom called intermittent claudication, which occurs when mineral-hardened arteries cannot deliver adequate blood flow to working muscles^[7][17]. This discomfort typically improves with rest. Some individuals experience high blood pressure that proves difficult to control, resulting from mineral deposits affecting the arteries. Though less common, serious cardiovascular events including angina, heart attacks, and strokes have been reported in people with pseudoxanthoma elasticum, particularly those who have additional cardiovascular risk factors^[4][7].

Gastrointestinal symptoms are relatively uncommon but can be serious when they occur. Some people experience bleeding from blood vessels in the digestive tract, which may appear as black, tar-like stools or frank blood, or manifest as chronic stomach upset^[4][7]. This bleeding results from fragile blood vessels in the stomach or intestines where elastic tissue has been affected by mineral deposits. Most individuals with pseudoxanthoma elasticum maintain a normal lifespan, though the quality of life can be significantly affected by vision loss, cardiovascular complications, or the psychosocial impact of visible skin changes.

Prevention

Because pseudoxanthoma elasticum results from inherited genetic mutations present from birth, there is no way to prevent the condition itself from developing in someone who carries two mutated copies of the ABCC6 gene. However, understanding genetic risks before or during pregnancy can help families make informed decisions. Genetic counseling provides couples with information about inheritance patterns, particularly valuable when one or both partners have a family history of the condition or are known carriers^[2]. For couples at risk, options such as prenatal testing through amniocentesis or chorionic villus sampling can detect whether a developing baby has inherited the condition, though these procedures carry their own small risks.

For individuals already diagnosed with pseudoxanthoma elasticum, prevention efforts focus on minimizing complications and slowing disease progression. Maintaining a healthy body weight represents one of the most important preventive measures, as excess weight places additional stress on an already compromised cardiovascular system^[16]. A body mass index (BMI) below 26 for men and 25 for women is recommended. Regular moderate exercise, such as walking or swimming for 30 to 45 minutes at least three times weekly, helps maintain circulation and build collateral blood vessels that can compensate for narrowed arteries^[11][16].

Dietary modifications can help reduce cardiovascular risk. A low-fat diet rich in fruits and vegetables, with at least five servings of produce daily, supports overall vascular health^[11][16]. Some experts recommend limiting dietary calcium intake to between 600 and 800 milligrams per day during childhood and adolescence, though this should be increased to about 1,000 milligrams during pregnancy to support fetal development and prevent osteoporosis in later life^[16]. Dietary supplements, particularly antioxidants including vitamins A, C, and E along with zinc and selenium, may offer protective benefits, especially for eye health, though evidence remains preliminary.

Avoiding certain substances and activities forms another crucial component of prevention. Tobacco use in any form must be completely avoided, as smoking’s effects on blood vessels significantly accelerate cardiovascular complications^[4][11]. Contact sports and activities that risk head trauma or eye injury, such as football, boxing, rugby, or shooting firearms, should be avoided to prevent retinal hemorrhages^[4][16]. Heavy lifting, particularly anything over 20 pounds, can stress the eyes and potentially trigger bleeding in vulnerable blood vessels^[16]. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen should be used sparingly if at all, as they increase the risk of gastrointestinal bleeding, though occasional use is generally acceptable^[2][11].

Regular monitoring enables early detection and treatment of complications before they cause permanent damage. People with pseudoxanthoma elasticum should see an eye specialist at least annually, with more frequent visits if any vision changes develop^[2]. Learning to use an Amsler grid at home, a simple tool that helps detect distortions in central vision, can provide early warning of retinal problems. Annual blood lipid profiles, including cholesterol and triglyceride measurements, help guide dietary or medication interventions to reduce cardiovascular risk^[16]. Blood pressure monitoring, either at home or through 24-hour ambulatory monitoring twice yearly, ensures hypertension is detected and treated promptly.

Pathophysiology

The fundamental abnormality in pseudoxanthoma elasticum involves the progressive accumulation of calcium and phosphate compounds in elastic fibers throughout the body, a process called dystrophic mineralization or ectopic calcification^[15]. Elastic fibers are essential components of connective tissue, the material that provides strength and flexibility to structures including skin, blood vessel walls, and membranes within the eye. These fibers normally stretch and recoil like microscopic rubber bands, allowing tissues to bend, expand, and return to their original shape. When calcium and other minerals infiltrate these fibers, they become stiff, fragmented, and eventually break apart, losing their elastic properties.

This mineralization particularly affects tissues naturally rich in elastic fibers. In the skin, the process concentrates in the mid and deep layers of the dermis, the thick layer beneath the skin’s surface, causing the characteristic yellowish papules and eventual looseness^[3]. In the eyes, the target is Bruch’s membrane, an elastic layer that separates the retina from its underlying blood supply. As minerals accumulate, this membrane develops tiny cracks—the angioid streaks visible during eye examinations. The cardiovascular system suffers when elastic fibers in the tunica media and tunica intima, layers within artery walls, undergo mineralization, causing vessels to stiffen and potentially narrow^[3].

The deposits themselves consist primarily of calcium hydrogen phosphate and calcium hydroxyapatite, chemical compounds similar to those found in bone, along with smaller amounts of iron^[15]. The presence of these bone-like minerals in soft tissues where they don’t belong creates the medical problems characteristic of the disease. Understanding why these minerals accumulate where they shouldn’t requires examining the molecular processes that normally prevent unwanted calcification throughout the body.

Current scientific understanding points to pseudoxanthoma elasticum being fundamentally a metabolic disorder rather than simply a problem with elastic fibers themselves. The ABCC6 protein, when functioning normally in liver and kidney cells, appears to facilitate the release or transport of substances that prevent mineralization in distant tissues^[1][15]. Research strongly suggests that one critical substance is adenosine triphosphate (ATP), the energy currency of cells. When released from cells, ATP can be broken down into other molecules, including adenosine monophosphate (AMP) and inorganic pyrophosphate (PPi).

Pyrophosphate serves as one of the body’s most powerful natural inhibitors of calcification, essentially preventing calcium and phosphate from crystallizing in soft tissues. When the ABCC6 protein is absent or non-functional due to genetic mutations, the release of ATP from liver cells appears to be impaired, resulting in insufficient production of pyrophosphate^[10][15]. Blood levels of pyrophosphate drop significantly in people with pseudoxanthoma elasticum. Without adequate levels of this protective compound circulating in the bloodstream and reaching distant tissues, calcium and phosphate minerals gradually deposit in elastic fibers, particularly in areas where turnover or stress on these fibers is highest.

The actual chemical composition of elastic fibers also changes in pseudoxanthoma elasticum. Normally, elastic fibers consist of a protein core called elastin surrounded by microfibrils made of other proteins. As mineralization progresses, these fibers become progressively shorter, clumped together, and fragmented, losing their organized structure^[8]. Eventually, the elastic network in affected tissues essentially disintegrates, replaced by calcified debris. This explains why the skin becomes loose and wrinkled, why blood vessels become stiff and prone to narrowing, and why Bruch’s membrane in the eye develops cracks that allow abnormal blood vessel growth.

The progression of pathophysiological changes follows a generally predictable sequence, though the timing and severity vary considerably between individuals. Mineralization typically begins in childhood or adolescence, even if not yet visible or symptomatic. The process continues throughout life, with the extent of calcification and tissue damage accumulating over decades. Some research suggests that individuals with certain combinations of ABCC6 mutations may experience slower progression or less severe manifestations than others, though the relationships between specific genetic variants and clinical outcomes remain an active area of investigation^[6].