Purpura

Thrombocytopenia (Purpura Hemorrhagic, Idiopathic Purpura). This disease is characterized by diminution of the platelets with prolonged bleeding time and a nonretractile blood clot. The coagu­lation time in glass is not markedly affected. Clinically, there are spontaneous hemor­rhages, epistaxis, menorrhagia and petechiae in the skin or mucous membranes. Children and young adults are most fre­quently affected. Capillary resistance is diminished and the so called tourniquet test is positive. In order to make a diag­nosis of primary purpura it is necessary to rule out acute leukemia or aplastic anemia. There is no enlarged spleen, such as occurs in Banti's disease, Gaucher's disease or hemolytic jaundice. The blood shows a re­duction of platelets, fewer than 60,000 per cubic. millimiter. and the platelets vary in size and staining characteristics. There may be an anemia due to blood loss, and a posthemorrhagic leukocytosis with relative lympho­cytosis. The marrow shows increased num­bers of megakaryocytes but inhibited plate­let production. Small, repeated transfusions of whole blood are temporarily beneficial. Splenectomy may be curative.
Anaphylactoid Purpura (Schonlein and Henoch's Purpura). this condition is due to increased permeability of the capillary endothelium which permits extravasation of blood into the tissue spaces. Henoch's variety is characterized by colic and other gastro-intestinal symptoms, which often precede the purpuric eruptions so that needless operations may be performed. Schonlein's purpura is characterized by effusion into the joints and periarticular structures, which may precede the purpuric manifes­tations so that an erroneous diagnosis of rheumatic fever may be made.

Myeloid Metaplasia (Megakaryocytic Myelosis). A number of cases have been reported which have in common megakaryocytic infiltrations of the bone marrow, liver and spleen. At times there is a marked leukocytosis with increased number of megakaryocytes in the peripheral blood, The constant features of the disease are the splenomegaly, the infiltration of the hemato­poietic organs with megakaryocytes, the tendency for the bone marrow to undergo progressive fibrosis and frequent fatal ter­mination. more recently, bacilli which take the acid-fast stain have been found in the lungs of these patients. Because of the in­volvement of the bone marrow by fibrosis, and the compensatory hematopoiesis in the spleen, splenectomy is contraindicated.

Polycythemia

The term polycythemia is applied to conditions in which the number of circulating red corpuscles is increased. Erythrocytosis indicates a symptomatic response to anoxia, which may occur in cardiac or pul­monary disease, or at high altitudes. Erythrocytosis is also produced by hypertrophy or tumors of the adrenal cortex, by certain poisons, such as aniline and its derivatives, phosphorus, and occasionally by some metals.

Erythremia or polycythemia vera is a chronic disease of obscure origin, with an increase in the total blood volume and the number of red blood cells. The patients have a plethoric complexion, splenic and hepatic enlargement and a variety of neurologic and vasomotor disturbances. Venous thromboses, bleeding tendency, varicosities and phlebitis, or arterial occlusion are common, due to alteration in the blood. Thrombi in the cerebral vessels may lead to hemiplegia or paresis. The red cell count varies from 7 to 10 million, as a rule. The hemoglobin may reach as high as 25 Gram (140%). The individual red corpuscles ap­pear normal. Leukocytosis is frequently present, and the platelet count may reach 4 million. Some patients develop leukemia.

Hemolytic Anemias

The hemolytic anemias are characterized by excessive blood destruction which results in such symptoms as jaundice, formation of gallstones, and increased amounts of urobilinogen and urobilin in the stools and urine. Phagocytosis of red blood cells undergoing destruction with deposition of hemo­siderin results in splenomegaly. The acute forms may result from bloodstream infec­tions or various types of hemolytic poisons. The chronic forms are often congenital dis­orders and include familial hemolytic icterus, Mediterranean anemia and sickle cell anemia.
Acute Hemolytic Anemia. Acute hemolytic anemia may result from mismatched transfusions, hemolytic toxins, such as snake venoms, bacterial toxins, phenyl hydrazine or phenol, and from malaria or bartonellosis. The symptoms include chills and rigor, vomiting and diarrhea, pain in the back and legs, hemoglobinuria, albuminuria and anuria. The red blood cells show marked variation in size and staining re­action. There is striking evidence of regen­eration, including reticulocytosis and cir­culating normoblasts. Treatment consists of removal of the cause.

Acquired and Congenital Hemolytic Icterus. In congenital hemolytic icterus repeated crises of blood destruction occur, with fever, abdominal pain and nausea. Once severe anemia and jaundice develop, they tend to persist. The spleen is enlarged, gallstones are found in 68 per cent of the cases, skeletal anomalies such as tower skull occur, and chronic leg ulcers are common. Reticulocytes, small dense red cells (sphcrocytes) and increased fragility of red cells to hypotonic salt solution are the chief blood findings. The acquired form is simi­lar to the congenital, but the increased fra­gility of the red blood cells may be absent. Both forms show an increased icteric index, at times as high as 100, and a hyperplastic bone marrow on sternal puncture. Both are benefited by splenectomy.
Sickle Cell Anemia. This is a hereditary disease in Negroes. It is characterized by the appearance of sickle-shaped red corpuscles in blood which has been standing away from oxygen two to six hours after it has been withdrawn and protected from drying. The cells show increased resistance to hypotonic salt solution. The patients suf­fer from jaundice, rheumatic pains in the extremities, leg ulcers, and irregular thick­enings of the cortex of the bones. There is no satisfactory treatment.
Mediterranean Anemia (Thalassanemia). This is a familial disease in individuals of Mediterranean stock. Those afflicted are often short in stature and have a large head. The bones about the hands and wrists may have increased density on roentgen exami­nation. Examination of the blood shows variations in the size and staining reactions of the red blood cells. Nucleated forms are common. The hemoglobin is concentrated at the periphery of the red corpuscle or as a central dot forming so-called target corpuscles. Uniformly colored cells are rare. There is often a leukocytosis. The icteric index is moderately increased. The spleen is enlarged and infarcts are common. Later the organ shrinks and is fibrosed. The bone marrow is hyperplastic. Severe forms are present in children; milder forms in adults. Transfusion is of temporary value but there is no specific treatment.

Erythroblastosis Fetalis. This is a hemolytic anemia, occuring late in fetal life or in the newborn, in a child whose blood agglutinogens differ from its mother's. As a regenerative response to blood destruction, the hematopoietic centers in the bone mar row, liver and spleen become crowded with erythroblasts, hemosiderin and foci of hematopoiesis. Nucleated red blood cells appear in the peripheral blood. The infant in severe cases is edematous and jaundiced, and hence the terms fetal hydrops and familial icterus gravis. The basal ganglia of the brain may be deeply icteric, so called kernicterus.In rare instances the incompatibility of the fetal and maternal bloods is because of the ABO grouping. However, the cause of the disease nearly always is the immunization of the RH negative mother by previ­ous transfusions with RH positive blood cells or by RH positive red cells of the fetus. The mother's RH antibodies pass into the fetal circulation and damage the child's erythrocytes. The offspring of an RH posi­tive father and RH negative mother always will be RH positive if the male is homozy­gous (all dominant genes for RH). If the RH positive father is heterozygous (one or two of the genes recessive) 50 per cent or less of the offspring will be RH positive. Levine found that 87 per cent of the white population is RH positive. The mothers of infants developing erythroblastosis fetalis belong to the 13 per cent who are RH nega­tive. The treatment consists of an adequate number of transfusions or exchange trans­fusions from a compatible RH negative donor.

Hypopoietic Anemias

Aplastic Anemias. The aplastic anemias may follow poisoning with benzol, arseni cals, gold or radiant energy (x-ray or radium). Idiopathic aplastic anemia may develop rapidly without known cause. There is a characteristic triad in these cases, con­sisting of progressively severe anemia, thrombocytopenia and leukopenia. The absence of a palpable spleen helps to distinguish this condition from aleukemic leu­kemia. The red corpuscles are normal in appearance. Nucleated and stippled forms and other signs of regeneration are absent. The bone marrow is hypoplastic. The white count usually shows 70 to 90 per cent lymphocytes. Repeated transfusions are usually the only remedy.
Repressive Anemia. This anemia is the simple chronic type, and occurs sympto matically in chronic infections, renal disease, malignancy, endocrine disorders, preg­nancy and vitamin deficiencies other than B 12. Erythropoiesis is inhibited by circula­tory toxins or other causes. The red cell count rarely Calls below 3.5 million. The number of cells, their size and the quantity of hemoglobin are proportionately decreased, so that the anemia is normocytic. Evidence of regeneration or increased blood destruction is usually absent.

Myelophthisic Anemias. This form of anemia is produced by replacement of the marrow by nonfunctioning elements. Metastatic carcinoma to bone, multiple mye­loma, myelosclerosis and lipoid storage dis­eases affecting bones are etilogic factors. Pain referred to the skeleton and spleno­megaly are often present. The anemia is variable in degree and most often normo cytic. Primitive red blood cells or leukocytes may be found in the peripheral circu­lation, together with reticulocytes and stippled cells. Roentgenography of the skeleton aids in diagnosis. Treatment must be directed to the underlying condition.