From Wikipedia, the free encyclopedia
|Classification and external resources|
|ICD-9||287.3, 287.4, 287.5|
A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. These limits are determined by the 2.5th lower and upper percentile, so values outside this range do not necessarily indicate disease. One common definition of thrombocytopenia is a platelet count below 50,000 per microliter.
 Signs and symptomsOften, low platelet levels do not lead to clinical problems; rather, they are picked up on a routine full blood count (or CBC, complete blood count). Occasionally, there may be bruising, particularly purpura in the forearms, petechia (pinpoint hemorrhages on skin and mucous membranes), nosebleeds and/or bleeding gums.
It is vital that a full medical history is elicited, to ensure the low platelet count is not due to a secondary process. It is also important to ensure that the other blood cell types, such as red blood cells and white blood cells, are not also suppressed. Painless, round and pinpoint (1 to 3 mm in diameter), petechiae usually appear and fade, and sometimes group to form ecchymoses. Larger than petechiae, ecchymoses are purple, blue or yellow-green bruises that vary in size and shape. They can occur anywhere on the body.
A person with thrombocytopenia may also complain of malaise, fatigue and general weakness (with or without accompanying blood loss). In acquired thrombocytopenia, the patient's history may include the use of one or several offending drugs.
Inspection typically reveals evidence of bleeding (petechiae or ecchymoses), along with slow, continuous bleeding from any injuries or wounds. Adults may have large, blood-filled bullae in the mouth. If the person's platelet count is between 30,000 and 50,000/mm3, bruising with minor trauma may be expected; if it is between 15,000 and 30,000/mm3, spontaneous bruising will be seen (mostly on the arms and legs).
 CausesDecreased platelet counts can be due to a number of disease processes:
 Decreased production
- Vitamin B12 or folic acid deficiency
- Leukemia or myelodysplastic syndrome
- Decreased production of thrombopoietin by the liver in liver failure.
- Sepsis, systemic viral or bacterial infection
- Dengue fever can cause thrombocytopenia by direct infection of bone marrow megakaryocytes as well as immunological shortened platelet survival
- Hereditary syndromes
- Congenital amegakaryocytic thrombocytopenia (CAMT)
- Thrombocytopenia absent radius syndrome
- Fanconi anemia
- Bernard-Soulier syndrome, associated with large platelets
- May-Hegglin anomaly, the combination of thrombocytopenia, pale-blue leuckocyte inclusions, and giant platelets
- Grey platelet syndrome
- Alport syndrome
- Wiskott–Aldrich syndrome
 Increased destruction
- Idiopathic thrombocytopenic purpura (ITP)
- Thrombotic thrombocytopenic purpura (TTP)
- Hemolytic-uremic syndrome (HUS)
- Disseminated intravascular coagulation (DIC)
- Paroxysmal nocturnal hemoglobinuria (PNH)
- Antiphospholipid syndrome
- Systemic lupus erythematosus (SLE)
- Post-transfusion purpura
- Neonatal alloimmune thrombocytopenia (NAITP)
- Splenic sequestration of platelets due to hypersplenism
- Dengue fever has been shown to cause shortened platelet survival and immunological platelet destruction
- HIV-associated thrombocytopenia
 Medication-inducedplatelets deficiency-inducing medications include:
- Direct myelosuppression
- Immunological platelet destruction
- Drug binds Fab portion of an antibody. The classic example of this mechanism is the quinidine group of drugs. The Fc portion of the antibody molecule is not involved in the binding process.
- Drug binds to Fc, and drug-antibody complex binds and activates platelets. Heparin induced thrombocytopenia (HIT) is the classic example of this phenomenon. In HIT, the heparin-antibody-platelet factor 4 (PF4) complex binds to Fc receptors on the surface of the platelet. Since Fc portion of the antibody is bound to the platelets, they are not available to the Fc receptors of the reticulo-endothelial cells, so therefore this system cannot destroy platelets as usual. This may explain why severe thrombocytopenia is not a common feature of HIT.
- Abciximab induced thrombocytopenia.
 Other causes
- Snakebites, particularly by pit vipers.
- Onyalai, a disease of unknown etiology seen only in parts of Africa, but suspected of being caused by poor nutrition or consumption of tainted food.
 Comparing coagulation tests
|Condition||Prothrombin time||Partial thromboplastin time||Bleeding time||Platelet count|
|Vitamin K deficiency or warfarin||prolonged||prolonged||unaffected||unaffected|
|Disseminated intravascular coagulation||prolonged||prolonged||prolonged||decreased|
|Von Willebrand disease||unaffected||prolonged||prolonged||unaffected|
|Early Liver failure||prolonged||unaffected||unaffected||unaffected|
|End-stage Liver failure||prolonged||prolonged||prolonged||decreased|
|Factor V deficiency||prolonged||prolonged||unaffected||unaffected|
|Factor X deficiency as seen in amyloid purpura||prolonged||prolonged||unaffected||unaffected|
Shehbaz Nawaz and Company ae going to make Millions (Billions actually) on the name of "Sprays". They love such ventures where large sums of money(fat commissions) are to be made. I won't be surprised if they are the ones spreading rumors,even mosquitoes!
I think Lahore would be "furthest" from the equator city to have regualr cases of Dengue if the scare is true. I am not sure what Americans have to do with it but this outbreak does not sound natural. We are a four season sub tropical country. A disease like this which has been around for centuries, suddenly appearing for years is not a likely events. I am sure it has raised a few red lights in GHQ IF the cases are real. But the thing is, I don't have the figures(neither do the media morons) for the test of actual virus(RNA replication test).
As far I know,only National health laboratory in Islamabad, Shaukat Khanam lab in Lahore and Agha Khan Lab in Karachi are equipped to carry that out. And it takes a few weeks. I don't even what to say. Call me a conpiracy theorist, but I think at least MOST of the dengue cases are a case of misdiagnosis(usually self). Young doctors are idiots and real doctors are too scared to tell everyone for the same reason I am after yesterday's little incident. Having second thoughts about telling people after my once best friend had a go at me and got a ear ful from me(would end up with a black eye if I see his ugly face anytime soon). And I knew the guy for over 10 years, Never mind the idiotpuna behind that though.
As Zaid Sahib correctly points outwe have to Fight this disinformation warfare no matter what:
يہ نغمہ فصل گل و لالہ کا نہيں پابند
بہار ہو کہ خزاں، لا الہ الا اللہ
اگرچہ بت ہيں جماعت کي آستينوں ميں
مجھے ہے حکم اذاں، لا الہ الا اللہ
خودي کا سر نہاں لا الہ الا اللہ