Pseudoxanthoma elasticum (PXE) is a rare genetic disorder that affects the connective tissues in the body, particularly the skin, eyes, and cardiovascular system. It is characterized by the abnormal mineralization of elastic fibers, which causes them to become calcified and brittle, leading to a variety of symptoms and complications.
Here are some specific definitions and types of PXE that may help you better understand the condition:
- Cutaneous PXE – This type of PXE primarily affects the skin and is characterized by yellowish papules or plaques that develop in areas of the body exposed to the sun, such as the neck, chest, and arms. The skin may also become lax and saggy, with a wrinkled appearance.
- Ocular PXE – This type of PXE affects the eyes and can lead to vision loss or blindness. It is characterized by the accumulation of mineralized material in the Bruch’s membrane, a layer of the retina that helps nourish the photoreceptor cells. This can cause the membrane to become thickened and ruptured, leading to bleeding and scarring.
- Cardiovascular PXE – This type of PXE affects the blood vessels and can lead to serious complications such as stroke, heart attack, and peripheral arterial disease. It is characterized by the mineralization and thickening of the arterial walls, which can cause the vessels to become narrow and stiff.
- Gastrointestinal PXE – This type of PXE affects the digestive system and can lead to gastrointestinal bleeding, abdominal pain, and other digestive problems. It is characterized by the mineralization and thickening of the walls of the stomach and intestines.
Causes
It is caused by mutations in the ABCC6 gene, which leads to the accumulation of mineral deposits in the elastic fibers of the body. Here are common causes of PXE:
- Genetics: PXE is an inherited disorder caused by mutations in the ABCC6 gene. It can be passed down from one generation to the next in an autosomal recessive pattern.
- Age: PXE usually becomes apparent in adolescence or early adulthood, but can also develop later in life.
- Gender: Women are more likely to develop PXE than men.
- Race: PXE is more common in Caucasians than other racial groups.
- Family history: If a family member has PXE, there is a higher likelihood that other family members will also have the disorder.
- Sun exposure: Sun damage can worsen the symptoms of PXE, particularly in the skin.
- Smoking: Smoking has been shown to increase the severity of PXE symptoms, particularly in the cardiovascular system.
- Diet: A diet high in calcium and vitamin D may increase the severity of PXE symptoms.
- Hormonal changes: Hormonal changes during pregnancy and menopause can worsen PXE symptoms in women.
- Medications: Certain medications, such as diuretics and anticoagulants, can worsen PXE symptoms.
- Chronic kidney disease: PXE has been associated with chronic kidney disease, which can worsen the symptoms of PXE.
- Liver disease: PXE has also been associated with liver disease, which can worsen the symptoms of PXE.
- Diabetes: Diabetes can worsen the symptoms of PXE, particularly in the eyes.
- Hypertension: High blood pressure can worsen the symptoms of PXE, particularly in the cardiovascular system.
- Obesity: Obesity can worsen the symptoms of PXE, particularly in the skin.
- Stress: Stress can worsen the symptoms of PXE, particularly in the eyes.
- Environmental factors: Exposure to certain environmental toxins, such as lead and mercury, can worsen the symptoms of PXE.
- Infections: Certain infections, such as hepatitis C, can worsen the symptoms of PXE.
- Autoimmune disorders: PXE has been associated with autoimmune disorders, which can worsen the symptoms of PXE.
- Trauma: Trauma to the skin or eyes can worsen the symptoms of PXE.
Symptoms
Symptoms of PXE can vary widely, and not all people with the disorder will experience all of these symptoms. However, there are some common signs and symptoms associated with PXE that can help with early detection and diagnosis. Here are symptoms of PXE, along with an explanation of each:
- Yellow bumps on the skin – These are called papules, and they can appear anywhere on the body, but are most commonly found in areas that experience a lot of sun exposure.
- Wrinkled skin – This is due to the loss of elasticity in the skin.
- Thickened skin – The skin may feel thicker and more leathery than normal.
- Folds in the skin – The skin may form creases and folds in areas where it is stretched.
- Loose skin – The skin may hang loosely in some areas due to the loss of elasticity.
- Small white or grayish spots on the retina – These are called angioid streaks, and they can cause vision problems.
- Decreased vision – This can be caused by angioid streaks, cataracts, or other eye problems associated with PXE.
- Abnormal blood vessels in the retina – This can lead to bleeding in the eye and other vision problems.
- Gastrointestinal bleeding – This can occur due to the formation of abnormal blood vessels in the digestive system.
- Angina – This is chest pain or discomfort that occurs when the heart muscle doesn’t receive enough oxygen-rich blood.
- Shortness of breath – This can occur due to heart or lung problems associated with PXE.
- High blood pressure – This can be caused by a narrowing of the arteries.
- Varicose veins – These are enlarged and twisted veins that can occur in the legs.
- Hemorrhoids – These are swollen veins in the anus and lower rectum that can cause pain and discomfort.
- Joint pain – This can occur due to the buildup of calcium in the joints.
- Stiffness in the joints – This can occur due to the loss of elasticity in the connective tissue.
- Bone spurs – These are bony growths that can occur in the joints.
- Calcification of blood vessels – This can lead to atherosclerosis and other cardiovascular problems.
- Kidney stones – These can occur due to the buildup of calcium in the kidneys.
- Hearing loss – This can occur due to the buildup of calcium in the inner ear.
Diagnosis
Here are common diagnoses and tests used to diagnose PXE and monitor its progression.
- Skin biopsy: A skin biopsy involves taking a small sample of skin tissue to examine under a microscope. This can help to identify the characteristic calcification of elastic fibers that is seen in PXE.
- Fundoscopy: Fundoscopy is an eye exam that allows the doctor to examine the back of the eye. In PXE, fundoscopy can reveal angioid streaks, which are thin, dark lines that radiate from the optic nerve.
- Optical coherence tomography (OCT): OCT is a non-invasive imaging technique that uses light waves to create detailed images of the eye. It can help to detect changes in the retina that are associated with PXE.
- Electroretinography (ERG): ERG is a test that measures the electrical activity of the retina in response to light. It can help to assess the function of the retina in patients with PXE.
- Visual acuity test: A visual acuity test measures how well a person can see at different distances. This is an important test for monitoring the progression of vision problems in PXE.
- Skin examination: A thorough skin examination can reveal the characteristic skin changes associated with PXE, including yellowish papules and plaques on the neck, axilla, and groin.
- Blood tests: Blood tests can be used to measure levels of calcium and phosphate, which can be elevated in patients with PXE.
- Urine tests: Urine tests can be used to measure levels of calcium and other minerals that may be abnormal in patients with PXE.
- Electrocardiogram (ECG): An ECG is a non-invasive test that measures the electrical activity of the heart. It can help to detect abnormalities in heart rhythm or structure in patients with PXE.
- Echocardiography: Echocardiography is an imaging test that uses sound waves to create detailed images of the heart. It can help to assess the structure and function of the heart in patients with PXE.
- Arterial ultrasound: An arterial ultrasound uses sound waves to create images of the arteries in the body. It can help to detect abnormalities in the blood vessels, such as thickening or narrowing, which may be seen in patients with PXE.
- Computed tomography (CT) scan: A CT scan is a non-invasive imaging test that uses X-rays to create detailed images of the body. It can help to assess the extent of calcification in the elastic tissue in patients with PXE.
- Magnetic resonance imaging (MRI): MRI is an imaging test that uses a magnetic field and radio waves to create detailed images of the body. It can be useful for assessing the extent of calcification in the elastic tissue and for identifying complications such as strokes or aneurysms.
- Angiography: Angiography is an imaging test that involves injecting a contrast dye into the blood vessels and taking X-rays to create detailed images of the blood vessels. It can be useful for identifying abnormalities in the blood vessels that may be associated with PXE.
- Bone density scan: A bone density scan uses X-rays to measure the density of bones in the body. It can help to assess the risk of osteoporosis, which may be increased in patients with PXE.
- Pulmonary function tests: Pulmonary function tests measure how well the lungs are functioning.
Treatment
Currently, there is no cure for PXE, but there are several treatments available to help manage the symptoms and slow the progression of the disease. Here are of the most common treatments for PXE:
- Vitamin K supplementation: Vitamin K has been shown to help reduce the deposition of calcium in the blood vessels and may help slow the progression of PXE.
- Magnesium supplementation: Magnesium can help regulate calcium metabolism and prevent the buildup of calcium in the tissues.
- Vitamin E supplementation: Vitamin E is an antioxidant that can help protect the skin and blood vessels from damage caused by oxidative stress.
- Ascorbic acid (vitamin C) supplementation: Vitamin C can help improve the production of collagen, a protein that helps give skin and blood vessels their elasticity.
- Topical retinoids: Retinoids, such as tretinoin, can help improve the appearance of skin lesions associated with PXE.
- Laser therapy: Laser therapy can be used to treat skin lesions and improve the appearance of the skin.
- Sclerotherapy: Sclerotherapy is a procedure in which a solution is injected into the affected blood vessels to help reduce their size and improve blood flow.
- Cryotherapy: Cryotherapy involves freezing the affected skin to help reduce the size of lesions.
- Surgical excision: In some cases, surgical excision may be necessary to remove large or painful skin lesions.
- Anti-inflammatory medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) can help reduce inflammation and pain associated with PXE.
- Statins: Statins are medications that can help lower cholesterol levels and may also help reduce the buildup of calcium in the blood vessels.
- Bisphosphonates: Bisphosphonates are medications that can help reduce the buildup of calcium in the bones and may also help prevent the deposition of calcium in the blood vessels.
- Angiotensin-converting enzyme (ACE) inhibitors: ACE inhibitors are medications that can help lower blood pressure and improve blood flow.
- Beta blockers: Beta blockers are medications that can help lower blood pressure and reduce the risk of cardiovascular complications associated with PXE.
- Calcium channel blockers: Calcium channel blockers are medications that can help relax the blood vessels and improve blood flow.
- Anticoagulants: Anticoagulants, such as warfarin, can help prevent the formation of blood clots in the blood vessels.
- Antiplatelet agents: Antiplatelet agents, such as aspirin, can help prevent the aggregation of platelets in the blood vessels and reduce the risk of blood clots.
- Photodynamic therapy: Photodynamic therapy involves the use of a photosensitizing agent and a light source to destroy abnormal cells in the skin.
- Gene therapy: Gene therapy involves the insertion of a normal copy of the ABCC6 gene into the patient’s cells to help restore the function of the protein.
- Stem cell therapy: Stem cell therapy involves the injection of stem cells into the affected tissues to help regenerate healthy tissue and improve blood flow.
While these treatments can help manage the symptoms of PXE and slow its progression, it is important to remember that there is no cure for this condition. Patients with PXE should work closely with their healthcare providers to develop a comprehensive
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