RT Book, Section A1 Wolff, Klaus A1 Johnson, Richard Allen A1 Saavedra, Arturo P. A1 Roh, Ellen K. SR Print(0) ID 1140791666 T1 SKIN SIGNS OF HEMATOLOGIC DISEASE T2 Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology, 8e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781259642197 LK dermatology.mhmedical.com/content.aspx?aid=1140791666 RD 2024/03/28 AB Thrombocytopenic purpura (TP) is characterized by cutaneous hemorrhages occurring in association with a reduced platelet count.Occur at sites of minor trauma/pressure (platelet count <40,000/μL) or spontaneously (platelet count <10,000/μL).Due to decreased platelet production, splenic sequestration, or increased platelet destruction.Decreased platelet production. Direct injury to bone marrow, drugs (cytosine arabinoside, daunorubicin, cyclophosphamide, busulfan, methotrexate, 6-mercaptopurine, vinca alkaloids, thiazide diuretics, ethanol, estrogens), replacement of bone marrow, aplastic anemia, vitamin deficiencies, and Wiskott–Aldrich syndrome.Splenic sequestration. Splenomegaly and hypothermia.Increased platelet destruction. Immunologic: Autoimmune TP, drug hypersensitivity (sulfonamides, quinine, quinidine, carbamazepine, digitoxin, or methyldopa), after transfusion. Nonimmunologic: Infection, prosthetic heart valves, disseminated intravascular coagulation, and thrombotic TP (microangiopathic hemolytic anemia, thrombocytopenia, neurologic abnormalities, fever and renal disease).Skin Lesions. Petechiae—Small (pinpoint to pinhead), red, nonblanching macules that are not palpable and turn brown as they get older (Fig. 20-1); later acquiring a yellowish-green tinge. Ecchymoses—Black-and-blue spots; larger area of hemorrhage. Vibices—linear hemorrhages (Fig. 20-1), due to trauma or pressure. Most common on legs and upper trunk, but may occur anywhere.Mucous Membranes. Petechiae—Most often on palate (Fig. 20-2) and gingival bleeding.General Examination. Possible CNS and internal hemorrhage, anemia.Laboratory Hematology. Thrombocytopenia.Serology. Rule out HIV disease; antibodies against ADAMTS 13 (a protease).Lesional Skin Biopsy (bleeding usually can be controlled by suturing biopsied site) to rule out vasculitis.Differential diagnosis. Senile purpura, purpura of scurvy, progressive pigmentary purpura (Schamberg disease), purpura following severe Valsalva maneuver (coughing, vomiting/retching), traumatic purpura, factitial or iatrogenic purpura, and vasculitis.Management. Identify underlying cause and correct, if possible. Oral glucocorticoids, high-dose IV immunoglobulins, or platelet transfusion for chronic ITP (splenectomy may be indicated).