skin hemosiderosis
Introduction
Introduction Hemosiderin is an unstable ferritin polymer containing iron brown pigment. Intravascular hemolysis produces excessive free hemoglobin excreted by the kidneys, producing hemoglobinuria, some of which are reabsorbed and degraded by renal tubular epithelial cells, producing hemosiderin, which, if surpassing the transport capacity of renal tubular epithelial cells, deposits in epithelial cells. Cell shedding is excreted in the urine to form hemosiderin, which is characterized by diffuse alveolar hemorrhage and secondary iron deficiency anemia. No other organs are involved. Due to repeated hemorrhage of the pulmonary capillaries, the exuded blood is hemolyzed, in which the globin is partially absorbed, and the hemosiderin is deposited on the lungs to react.
Cause
Cause
There are two main speculations:
1 Developmental defects, due to abnormal development and functional dysfunction of the primary alveolar epithelium, impaired the mechanical stability of the blood vessels, or defects in the development of elastic fibers of the lungs, but could not be confirmed by histological examination.
2 caused by immune response. There may be accumulation of mast cells in the lungs of the patient; increased plasma cells in the reticuloendothelial system; eosinophilia in patients 1/8 to 1/5; and other immune diseases in a few cases. It has been found that some infants who have been confirmed or may be pulmonary hemosiderosis have a positive skin test with milk and are positive for serum milk precipitin. Symptoms disappear after withdrawal from milk. However, some of the children who have been confirmed to have pulmonary hemosiderosis have a negative reaction.
Examine
an examination
Related inspection
Sputum microscopy for delayed skin allergic alveolar gas-arterial oxygen partial pressure difference
Signs:
The disease is more common in children, mainly in the 1 to 7 years old, 15% over 15 years old, the ratio of male to female is 2:1, no obvious familial. Symptoms depend on the extent of intrapulmonary bleeding. Mild persistent chronic bleeding can have dry cough, fatigue, pale skin, weight loss, and even clubbing. During acute bleeding, blood in the sputum, hemoptysis, low fever, chest pain, etc. may occur. In the later stages, there may be difficulty in breathing, and even insufficiency of cardiac function. In the acute phase and secondary infections, there may be obvious wet rales. Fecal occult blood is positive.
The X-ray showed a fusion of spotted shadows in the middle and lower parts of the lungs. After the pulmonary hemorrhage stopped, the shadows improved within a few weeks. In patients with persistent moderate bleeding, the lesions in the lungs may be miliary.
Diagnosis
Differential diagnosis
Skin and mucous pigmentation spots: Skin and mucous membrane spots are a symptom of multiple gastrointestinal polyp syndrome. Multiple gastrointestinal polyp syndrome refers to the occurrence of multiple polyps in the digestive tract (for young metaplastic or inflammatory polyps), abnormal ectoderm and severe intermittent diarrhea, abdominal pain, limbs A group of syndromes of gastrointestinal and neurological symptoms such as numbness and tingling.
Skin pigmentation is bronze: salt-induced nephritis has typical clinical manifestations, polyuria and nocturia, skin pigmentation is bronze, etc., salt-loss nephritis, also known as Thorn syndrome, is currently considered to be a group of severe kidneys. Sexual loss of salt is a special type of certain kidney disease characterized by sex.
Skin pigmentation: The color of the skin is determined by the melanin (brown), carotene (yellow), oxidized hemoglobin (red) in the dermal capillaries, and reduced hemoglobin (blue) in the vein. important. In addition to ethnic and individual differences in the color of the skin, normal people often have physiological pigmentation in the exposed parts, wrinkles and rubbed parts; therefore, the change of skin color should be compared with the skin around the patient and the affected part. It should not be judged solely from the depth of color.
