A fine yellow verrucous rash is commonly seen in acute neurologic Niemann-Pick disease, which is also known as sphingomyelin deposition disease, an inborn disorder of glycolipid metabolism. It is characterized by a large number of neural sphingomyelin-containing foam cells throughout the mononuclear macrophages and the nervous system. What are the tests for fine yellow verrucous rash? 1.Blood picture hemoglobin is normal or with mild anemia; leukopenia is apparent when hypersplenism is present. Monocytes and lymphocytes often show characteristic vacuoles, about 8 to 10, which have diagnostic value. Electron microscopically these vacuoles are lysosomes filled with lipids. Platelet counts are normal, and are reduced in advanced stages with hypersplenism and time to significant bone marrow invasion. The patient’s leukocytes lacked neurophospholipase activity. 2, the bone marrow image contains typical Nislau-Pick cells, often called foam cells, the nuclei of the cell diameter of 20 ~ 100 μm. nuclei smaller, round or oval, usually a single, there can also be a double nucleus. The nuclei were small, round or ovoid, usually single, and could be binucleated. The cytoplasm was abundant and filled with round droplet-shaped transparent vesicles, similar to mulberry or foam. Electron microscopy showed that the vesicles were surrounded by some membrane layer structures. Examination of unstained specimens by phase microscopy shows small vesicles in the cytoplasm, unlike Gaucher cells. Under polarized light, the vesicles are birefringent. Under ultraviolet light, the fluorescence is greenish-yellowish. Biochemical characteristics of PAS reaction is weakly positive, intracytoplasmic vesicle wall is positive, vesicle center is negative; acid phosphatase, alkaline phosphatase, Sudan black are negative reaction. 3.Plasma cholesterol and total lipids may be elevated, and SGPT is mildly elevated. 4.Urinary excretion of nerve sphingomyelin is significantly increased. 5, Liver, spleen and lymph node biopsy have heaps, patches or diffuse foam cell infiltration. Nerve sheath phospholipids. 6, X-ray examination: no characteristic X-ray manifestations, in long-term survival cases, due to lipid-filled histiocytes in the bones of a large number of proliferation can be manifested in osteoporosis, medullary cavity widening, thinning of the bone cortex, and even the long bones can appear focal destruction of the area, but there is no skeleton expansion deformity changes. After infancy, the alveoli are infiltrated by lipid-filled histiocytes, and the lungs can be seen to resemble histiocytosis X. In addition, there is no specificity of the disease. In short, it is not specific and only provides the basis for secondary diagnosis. 7. Determine the sphingomyelinase activity of leukocytes or cultured fibroblasts, and the activity of each type of enzyme is different.