Overview.
Elastofibrous pseudoxanthoma was earlier known as diffuse xanthomatosis, and later as atypical xanthoma and dystrophic elastofibrosis. It is a congenital disease that can invade many organs and systems of the body and produce a wide variety of clinical manifestations. The basic pathological changes are degenerative changes in the skin, eyes and cardiovascular system caused by congenital defects of elastic and collagen fibers. The disease is more common in young women.
Etiology
The disease is a genetic defect of elastic fibers throughout the body. The application of gene chain analysis and mutation detection techniques has demonstrated a strong correlation between its pathogenesis and the ABCC6 mutation. It has been categorized into two types and four groups according to its genetic features. Two types and autosomal dominant inheritance and autosomal negative inheritance, and each of the two types is divided into two groups. Clinically, autosomal recessive group I and autosomal dominant groups I and II are common, and autosomal recessive group II is rare, with only isolated reports.
Symptoms
1. Skin damage
It usually occurs in children or young adults, but can also be seen shortly after birth. The skin rash is symmetrical, occurring on both sides of the neck, around the umbilicus, armpits, popliteal fossa and inguinal folds, and can also be seen in the oral cavity, nasal mucosa, and occasionally in the vagina or rectal mucosa. The skin is thickened, poorly elastic, and flaccid. The rash is pinhead-sized to bean-sized, yellowish to orange papules or nodules, mostly distributed in clusters or fused into a network. Some of the pores are enlarged, like “plucked chicken skin”, with an orange peel appearance. Some patients may have overstretching of the skin, but not necessarily a rash.
2. Cardiovascular damage
Including peripheral vascular disease, hypertension, coronary artery disease and endothelial fibrosis and calcification. When the arteries of the limbs are involved, there may be weakened or absent pulse and intermittent claudication. A small number of patients have angina attacks, congestive heart failure may be related to a variety of factors, vascular disease and endocardial fibrosis can cause heart failure, hypertension and coronary heart disease is also an important factor in promoting heart failure.
3. Gastrointestinal lesions
This disease is often accompanied by gastrointestinal symptoms, including gastrointestinal bleeding is the most serious, the bleeding site can be the large intestine and the upper gastrointestinal tract, bleeding occurs at an early age, the average age of 26 years old, the youngest is only 6 years old. Gastroscopy can find yellow pebble-like mucosal rash in the digestive tract mucosa, sometimes forming mucosal folds.
4. Ocular lesions
The radial angioid pattern of retinal blood vessels in the fundus of the eye is the characteristic change of this disease. Early or mild patients only have hyperpigmentation around the macula and speckled changes, over time this change is manifested as a thicker gray-white lines of blood vessels, around the optic disc in an irregular ring or radial distribution. Retinal hemorrhages can cause visual impairment. With age, proliferative changes, hyperpigmentation, retinal macula, choroidal vitelliform degeneration, and retinal scarring can occur. When the macula is involved, severe vision loss can occur.
5. Neuropsychiatric lesions
Neuropsychiatric symptoms may be caused by cerebrovascular lesions, including mild hemiparesis, mental abnormality, subarachnoid hemorrhage, basilar artery insufficiency, and epilepsy.
6. Renal lesions
Both intrarenal and extrarenal arteries can be affected, and renal vascular involvement can lead to hypertension.
Examination
Histopathological examination: the characteristic changes in the skin are dermal elastic fiber degeneration, swelling, increased number and calcification. The lesions are predominantly in the middle of the dermis, with less severe lesions in the upper and lower parts of the dermis. Healthy-looking skin may also have mild histologic changes. Early lesions consist of calcium deposits around the sweat glands. In the typical rash, calcification around the sweat glands is more pronounced, and the elastic fibers of the dermis are swollen, deeply stained, twisted, broken, containing amorphous granules, or even irregularly fragmented and granular, and large areas of calcified tissue may be present at the same time.
Diagnosis
Primary criteria: ① yellow cobblestone lesions on the flexion side; ② characteristic histologic features of the lesions; ③ retinal vascular pattern.
Secondary criteria: ① no characteristic histologic changes in the skin of the lesion. ② Family history of first-degree relatives.
Treatment
There is no specific treatment for this disease, and symptomatic treatment is mostly used. If the skin folds are too extensive, orthopedic surgery is feasible. Those with gastrointestinal bleeding should be given blood transfusion and hemostatic drugs. Those with hypertension or coronary artery blood supply insufficiency should be given vasodilator, anticoagulant therapy and thrombolytic agents such as urokinase. Once heart failure and cerebrovascular accident occur, appropriate treatment should be given. Application of vitaminase and vitamin E is effective in relieving skin lesions and eye symptoms.