There is increasing use of immunosuppressants such as mycophenolate mofetil and azathioprine because of their effectiveness. In chronic refractory cases, where immune pathogenesis has been confirmed, the off-label use of the "vinca" alkaloid and chemotherapy agent vincristine may be attempted. However, vincristine has significant side effects and its use in treating ITP must be approached with caution, especially in children.

Thrombopoietin receptor agonists are pharmaceutical agents that stimulate platelet production in the bone marrow. In this, they differ from the previously discussed agents that act by attempting to curtail platelet destruction. Two such products are currently available:

- Romiplostim (trade name Nplate) is a thrombopoiesis stimulating Fc-peptide fusion protein (peptibody) that is administered by subcutaneous injection. Designated an orphan drug in 2003 under United States law, clinical trials demonstrated romiplostim to be effective in treating chronic ITP, especially in relapsed post-splenectomy patients. Romiplostim was approved by the United States Food and Drug Administration (FDA) for long-term treatment of adult chronic ITP on August 22, 2008.

- Eltrombopag (trade name Promacta in the USA, Revolade in the EU) is an orally-administered agent with an effect similar to that of romiplostim. It too has been demonstrated to increase platelet counts and decrease bleeding in a dose-dependent manner. Developed by GlaxoSmithKline and also designated an orphan drug by the FDA, Promacta was approved by the FDA on November 20, 2008.

Side effects of thrombopoietin receptor agonists include headache, joint or muscle pain, dizziness, nausea or vomiting, and an increased risk of blood clots.

Often, no treatment is required or necessary for reactive thrombocytosis. In cases of reactive thrombocytosis of more than 1,000x10/L, it may be considered to administer daily low dose aspirin (such as 65 mg) to minimize the risk of stroke or thrombosis.

However, in primary thrombocytosis, if platelet counts are over 750,000 or 1,000,000, and especially if there are other risk factors for thrombosis, treatment may be needed. Selective use of aspirin at low doses is thought to be protective. Extremely high platelet counts in primary thrombocytosis can be treated with hydroxyurea (a cytoreducing agent) or anagrelide (Agrylin).

In Jak-2 positive disorders, ruxolitinib (Jakafi) can be effective.

Treatment is guided by the severity and specific cause of the disease. Treatment focuses on eliminating the underlying problem, whether that means discontinuing drugs suspected to cause it or treating underlying sepsis. Diagnosis and treatment of serious thrombocytopenia is usually directed by a hematologist. Corticosteroids may be used to increase platelet production. Lithium carbonate or folate may also be used to stimulate platelet production in the bone marrow.

Discontinuation of heparin is critical in a case of heparin-induced thrombocytopenia (HIT). Beyond that, however, clinicians generally treat to avoid a thrombosis, often by starting patients directly on warfarin. For this reason, patients are usually treated with a direct thrombin inhibitor, such as lepirudin or argatroban, which are approved by the FDA for this use. Other blood thinners sometimes used in this setting that are not FDA-approved for treatment of HIT include bivalirudin and fondaparinux. Platelet transfusions are not routinely used to treat HIT because thrombosis, not bleeding, is the primary problem.

There has been no general recommendation for treatment of patients with Giant Platelet Disorders, as there are many different specific classifications to further categorize this disorder which each need differing treatments. Platelet transfusion is the main treatment for people presenting with bleeding symptoms. There have been experiments with DDAVP (1-deamino-8-arginine vasopressin) and splenectomy on people with Giant platelet disorders with mixed results, making this type of treatment contentious.

Initial treatment is with glucocorticoid corticosteroids or intravenous immunoglobulin, a procedure that is also used in ITP cases. In children, good response to a short steroid course is achieved in approximately 80 percent of cases. Although the majority of cases initially respond well to treatment, relapses are not uncommon and immunosuppressive drugs (e.g. ciclosporin, mycophenolate mofetil, vincristine and danazol) are subsequently used, or combinations of these.

The off-label use of rituximab (trade name Rituxan) has produced some good results in acute and refractory cases, although further relapse may occur within a year. Splenectomy is effective in some cases, but relapses are not uncommon.

The only prospect for a permanent cure is the high-risk option of an allogeneic hematopoietic stem cell transplantation (SCT).

Given the fact that HIT predisposes strongly to new episodes of thrombosis, it is not sufficient to simply discontinue the heparin administration. Generally, an alternative anticoagulant is needed to suppress the thrombotic tendency while the generation of antibodies stops and the platelet count recovers. To make matters more complicated, the other most commonly used anticoagulant, warfarin, should not be used in HIT until the platelet count is at least 150 x 10^9/L because there is a very high risk of warfarin necrosis in people with HIT who have low platelet counts. Warfarin necrosis is the development of skin gangrene in those receiving warfarin or a similar vitamin K inhibitor. If the patient was receiving warfarin at the time when HIT is diagnosed, the activity of warfarin is reversed with vitamin K. Transfusing platelets is discouraged, as there is a theoretical risk that this may worsen the risk of thrombosis; the platelet count is rarely low enough to be the principal cause of significant hemorrhage.

Various non-heparin agents are used to provide anticoagulation in those with strongly suspected or proven HIT: danaparoid, fondaparinux, bivalirudin and argatroban. These are alternatives to heparin therapy. Not all agents are available in all countries, and not all are approved for this specific use. For instance, argatroban is only recently licensed in the United Kingdom, and danaparoid is not available in the United States. Fondaparinux, a Factor Xa inhibitor, is commonly used off label for HIT treatment in the United States.

According to a systematic review, people with HIT treated with lepirudin showed a relative risk reduction of clinical outcome (death, amputation, etc.) to be 0.52 and 0.42 when compared to patient controls. In addition, people treated with argatroban for HIT showed a relative risk reduction of the above clinical outcomes to be 0.20 and 0.18. Lepirudin production stopped on May 31, 2012.

Treatment for individuals with X-linked thrombocytopenia is typically focused on managing symptoms of the disorder. Splenectomy has been shown to improve platelet counts but also significantly increases the risk of life-threatening infections for patients with XLT. Therefore, these individuals must take antibiotics for the rest of their life to avoid fatal bacteremia. In the event of significant bleeding, platelet transfusions should be administered. Circumcision should be avoided for infant males with XLT due to the risk of bleeding and infection. Regular follow ups to track blood counts should be utilized as well as confirming that any medications, over the counter or prescription, will not interfere with platelet functioning.

For patients with vWD type 1 and vWD type 2A, desmopressin is available as different preparations, recommended for use in cases of minor trauma, or in preparation for dental or minor surgical procedures. Desmopressin stimulates the release of vWF from the Weibel-Palade bodies of endothelial cells, thereby increasing the levels of vWF (as well as coagulant factor VIII) three- to five-fold. Desmopressin is also available as a preparation for intranasal administration (Stimate) and as a preparation for intravenous administration. Recently, the FDA has approved the use of Baxalta’s Vonvendi. This is the first recombinant form of vWF. The effectiveness of this treatment is different than desmopressin because it only contains vWF, not vWF with the addition of FVIII. This treatment is only recommended for use by individuals who are 18 years of age or older.

Desmopressin is contraindicated in vWD type 2b because of the risk of aggravated thrombocytopenia and thrombotic complications. Desmopressin is probably not effective in vWD type 2M and is rarely effective in vWD type 2N. It is totally ineffective in vWD type 3.

For women with heavy menstrual bleeding, estrogen-containing oral contraceptive medications are effective in reducing the frequency and duration of the menstrual periods. Estrogen and progesterone compounds available for use in the correction of menorrhagia are ethinylestradiol and levonorgestrel (Levona, Nordette, Lutera, Trivora). Administration of ethinylestradiol diminishes the secretion of luteinizing hormone and follicle-stimulating hormone from the pituitary, leading to stabilization of the endometrial surface of the uterus.

Desmopressin is a synthetic analog of the natural antidiuretic hormone vasopressin. Its overuse can lead to water retention and dilutional hyponatremia with consequent convulsion.

For patients with vWD scheduled for surgery and cases of vWD disease complicated by clinically significant hemorrhage, human-derived medium purity factor VIII concentrates, which also contain von Willebrand factors, are available for prophylaxis and treatment. Humate P, Alphanate, Wilate and Koate HP are commercially available for prophylaxis and treatment of vWD. Monoclonally purified factor VIII concentrates and recombinant factor VIII concentrates contain insignificant quantity of vWF, so are not clinically useful.

Development of alloantibodies occurs in 10-15% of patients receiving human-derived medium-purity factor VIII concentrates and the risk of allergic reactions including anaphylaxis must be considered when administering these preparations. Administration of the latter is also associated with increased risk of venous thromboembolic complications.

Blood transfusions are given as needed to correct anemia and hypotension secondary to hypovolemia. Infusion of platelet concentrates is recommended for correction of hemorrhage associated with platelet-type vWD.

The antifibrinolytic agents epsilon amino caproic acid and tranexamic acid are useful adjuncts in the management of vWD complicated by clinical hemorrhage. The use topical thrombin JMI and topical Tisseel VH are effective adjuncts for correction of hemorrhage from wounds.

Recent research has suggested that hematopoietic stem cell transplantation may be a treatment option for patients with XLT despite associated risks. Other studies have shown that treatment with corticosteroids or intravenous immunoglobulin in any dose or duration may have a beneficial impact on platelet counts, although transiently. Furthermore, research has shown that splenectomy may not be a good treatment option for patients with XLT as it increases the risk of severe infections. This same research showed that patients with XLT have a high overall survival rate but they are at risk for severe life-threatening complications associated with this disorder, such as serious bleeding events and malignancies.

Patient with KMS can be extremely ill and may need intensive care. They are at risk of bleeding complications including intracranial hemorrhage. The thrombocytopenia and coagulopathy are managed with platelet transfusions and fresh frozen plasma, although caution is needed due to the risk of fluid overload and heart failure from multiple transfusions. The possibility of disseminated intravascular coagulation, a dangerous and difficult-to-manage condition, is concerning. Anticoagulant and antiplatelet medications can be used after careful assessment of the risks and benefits.

Treatment is directed at the prevention of haemorrhagic shock. Standard dose prednisolone does not increase the platelet count. High-dose methylprednisolone therapy in children with Onyalai has been shown to improve platelet count and reduce the requirement for transfusions. Vincristine sulphate may be of benefit to some patients. Splenectomy is indicated in patients with severe uncontrollable haemorrhage. High-dose intravenous gammaglobulin may help in increasing the platelet count and cessation of haemorrhage.

Cordocentesis can be performed in utero to determine the platelet count of the fetus. This procedure is only performed if a "prior" pregnancy was affected by . Intrauterine transfusions can be performed during cordocentesis for primary prevention of intracerebral hemorrhage. Any administered cellular blood products must be irradiated to reduce the risk of graft-versus-host disease in the fetus. Additionally, all administered blood products should be reduced-risk ( seronegative and leukoreduced are considered essentially equivalent for the purposes of risk reduction).

If intrauterine platelet transfusions are performed, they are generally repeated weekly (platelet lifespan after transfusion is approximately 8 to 10 days). Platelets administered to the fetus must be negative for the culprit antigen (often -1a, as stated above). Many blood suppliers (such as American Red Cross and United Blood Services) have identified -1a negative donors. An alternative donor is the mother who is, of course, negative for the culprit antigen. However, she must meet general criteria for donation and platelets received from the mother must be washed to remove the offending alloantibody and irradiated to reduce the risk of graft-versus-host disease. If platlet transfusions are needed urgently, incompatible platelets may be used, with the understanding that they may be less effective and that the administration of any blood product carries risk.

The use of Intravenous immunoglobulin () during pregnancy and immediately after birth has been shown to help reduce or alleviate the effects of in infants and reduce the severity of thrombocytopenia. The most common treatment is weekly infusions at a dosage of 1 g/kg beginning at 16 to 28 weeks of pregnancy, depending on the severity of the disease in the previous affected child, and continuing until the birth of the child. In some cases this dosage is increased to 2 g/kg and/or combined with a course of prednisone depending on the exact circumstances of the case. Although this treatment has not been shown to be effective in all cases it has been shown to reduce the severity of thrombocytopenia in some. Also, it is suspected that (though not understood why) provides some added protection from intercranial haemorrhage () to the fetus. Even with treatment, the fetal platelet count may need to be monitored and platelet transfusions may still be required.

The goal of both and platelet transfusion is to avoid hemorrhage. Ultrasound monitoring to detect hemorrhage is not recommended as detection of intracranial hemorrhage generally indicates permanent brain damage (there is no intervention that can be performed to reverse the damage once it has occurred).

Before delivery, the fetal platelet count should be determined. A count of >50,000 μL is recommended for vaginal delivery and the count should be kept above 20,000 μL after birth.

In terms of treatment/management, bleeding events can be controlled by platelet transfusion.

Most heterozygotes, with few exceptions, do not have a bleeding diathesis. BSS presents as a bleeding disorder due to the inability of platelets to bind and aggregate at sites of vascular endothelial injury. In the event of an individual with mucosal bleeding tranexamic acid can be given.

The affected individual may need to avoid contact sports and medications such as aspirin, which can increase the possibility of bleeding. A potential complication is the possibility of the individual producing antiplatelet antibodies

Management of KMS, particularly in severe cases, can be complex and require the joint effort of multiple subspecialists. This is a rare disease with no consensus treatment guidelines or large randomized controlled trials to guide therapy.

The effect of antibiotics in "E. coli" O157:H7 colitis is controversial. Certain antibiotics may stimulate further verotoxin production and thereby increase the risk of HUS. However, there is also tentative evidence that some antibiotics like quinolones may decrease the risk of hemolytic uremic syndrome. In the 1990s a group of pediatricians from the University of Washington used a network of 47 cooperating laboratories in Washington, Oregon, Idaho, and Wyoming to prospectively identify 73 children younger than 10 years of age who had diarrhea caused by "E. coli" O157:H7 The hemolytic–uremic syndrome developed in 5 of the 9 children given antibiotics (56 percent), and in 5 of the 62 children who were not given antibiotics (8 percent, P<0.001).

Treatment of HUS is generally supportive, with dialysis as needed. Platelet transfusion may actually worsen the outcome.

In most children with postdiarrheal HUS, there is a good chance of spontaneous resolution, so observation in a hospital is often all that is necessary, with supportive care such as hemodialysis where indicated. If a diagnosis of STEC-HUS is confirmed, plasmapheresis (plasma exchange) is contraindicated. However, plasmapheresis may be indicated when there is diagnostic uncertainty between HUS and TTP.

There are case reports of experimental treatments with eculizumab, a monoclonal antibody against CD5 that blocks part of the complement system, being used to treat congenital atypical hemolytic uremic syndrome, as well as severe shiga-toxin associated hemolytic uremic syndrome. These have shown promising results. Eculizeumab was approved by the U.S. Food and Drug Administration (FDA) on March 13, 2007 for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), a rare, progressive, and sometimes life-threatening disease characterized by excessive hemolysis; and on September 23, 2011 for the treatment of atypical hemolytic uremic syndrome (aHUS) It was approved by the European Medicines Agency for the treatment of PNH on June 20, 2007, and on November 29, 2011 for the treatment of aHUS. However, of note is the exceedingly high cost of treatment, with one year of the drug costing over $500,000.

Scientists are trying to understand how useful it would be to immunize humans or cattles with vaccines.

The primary treatment for CAMT is bone marrow transplantation.

Bone Marrow/Stem Cell Transplant is the only thing that ultimately cures this genetic disease. Frequent platelet transfusions are required to ensure that platelet levels do not fall to dangerous levels, although this is not always the case. It is known for patients to continue to create very small numbers of platelets over time.

Immune thrombocytopenic purpura (), sometimes called idiopathic thrombocytopenic purpura is a condition in which autoantibodies are directed against a patient's own platelets, causing platelet destruction and thrombocytopenia. Anti-platelet autoantibodies in a pregnant woman with immune thrombocytopenic purpura will attack the patient's own platelets and will also cross the placenta and react against fetal platelets. Therefore, is a significant cause of fetal and neonatal immune thrombocytopenia. Approximately 10% of newborns affected by will have platelet counts <50,000 μL and 1% to 2% will have a risk of intracerebral hemorrhage comparable to infants with .

Mothers with thrombocytopenia or a previous diagnosis of should be tested for serum antiplatelet antibodies. A woman with symptomatic thrombocytopenia and an identifiable antiplatelet antibody should be started on therapy for their which may include steroids or . Fetal blood analysis to determine the platelet count is not generally performed as -induced thrombocytopenia in the fetus is generally less severe than . Platelet transfusions may be performed in newborns, depending on the degree of thrombocytopenia.

Treatment of Wiskott–Aldrich syndrome is currently based on correcting symptoms. Aspirin and other nonsteroidal anti-inflammatory drugs should be avoided, since these may interfere with platelet function. A protective helmet can protect children from bleeding into the brain which could result from head injuries. For severely low platelet counts, patients may require platelet transfusions or removal of the spleen. For patients with frequent infections, intravenous immunoglobulins (IVIG) can be given to boost the immune system. Anemia from bleeding may require iron supplementation or blood transfusion.

As Wiskott–Aldrich syndrome is primarily a disorder of the blood-forming tissues, a hematopoietic stem cell transplant, accomplished through a umbilical cord blood or bone marrow transplant offers the only current hope of cure. This may be recommended for patients with HLA-identical donors, matched sibling donors, or even in cases of incomplete matches if the patient is age 5 or under.

Studies of correcting Wiskott–Aldrich syndrome with gene therapy using a lentivirus have begun.

Proof-of-principle for successful hematopoietic stem cell gene therapy has been provided for patients with Wiskott–Aldrich syndrome.

Currently, many investigators continue to develop optimized gene therapy vectors. In July 2013 the Italian San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET) reported that three children with Wiskott–Aldrich syndrome showed significant improvement 20–30 months after being treated with a genetically modified lentivirus. In April 2015 results from a follow-up British and French trial where six children with Wiskott–Aldrich syndrome were treated with gene therapy were described as promising. Median follow-up time was 27 months.

Treatments range from platelet transfusions to surgery aimed at either centralizing the hand over the ulna to improve functionality of the hand or aimed at 'normalizing' the appearance of the arm, which is much shorter and 'clubbed.' There is some controversy surrounding the role of surgery. The infant mortality rate has been curbed by new technology, including platelet transfusions, which can even be performed in utero. The critical period is the first and sometimes second year of life. For most people with TAR, platelet counts improve as they grow out of childhood.

The only effective treatment is prompt delivery of the baby. Several medications have been investigated for the treatment of HELLP syndrome, but evidence is conflicting as to whether magnesium sulfate decreases the risk of seizures and progress to eclampsia. The disseminated intravascular coagulation is treated with fresh frozen plasma to replenish the coagulation proteins, and the anemia may require blood transfusion. In mild cases, corticosteroids and antihypertensives (labetalol, hydralazine, nifedipine) may be sufficient. Intravenous fluids are generally required. Hepatic hemorrhage can be treated with embolization, as well, if life-threatening bleeding ensues.

The University of Mississippi standard protocol for HELLP includes corticosteroids. However, a 2009 review found "no conclusive evidence" supporting corticosteroid therapy, and a 2010 systematic review by the Cochrane Collaboration also found "no clear evidence of any effect of corticosteroids on substantive clinical outcomes" either for the mothers or for the newborns,

High platelet levels do not necessarily signal any clinical problems, and are picked up on a routine full blood count. However, it is important that a full medical history be elicited to ensure that the increased platelet count is not due to a secondary process. Often, it occurs in tandem with an inflammatory disease, as the principal stimulants of platelet production (e.g. thrombopoietin) are elevated in these clinical states as part of the acute phase reaction.

High platelet counts can occur in patients with polycythemia vera (high red blood cell counts), and is an additional risk factor for complications.

A very small segment of patients report symptoms of erythromelalgia, a burning sensation and redness of the extremities that resolves with cooling and/or aspirin use.

Scientific literature sometimes excludes thrombocytosis from the scope of thrombophilia by definition, but practically, by the definition of thrombophilia as an increased predisposition to thrombosis, thrombocytosis (especially primary thrombocytosis) is a potential cause of thrombophilia. Conversely, secondary thrombocytosis very rarely causes thrombotic complications.

Giant platelet disorders are rare disorders featuring abnormally large platelets, thrombocytopenia and a tendency to bleeding. Giant platelets cannot stick adequately to an injured blood vessel walls, resulting in abnormal bleeding when injured. Giant platelet disorder occurs for inherited diseases like Bernard-Soulier syndrome, gray platelet syndrome and May-Hegglin anomaly.

PTP is rare, but usually occurs in women who have had multiple pregnancies or in people who have undergone previous transfusions. The precise mechanism leading to PTP is unknown, but it most commonly occurs in individuals whose platelets lack the HPA-1a antigen (old name: PL). The patient develops antibodies to the HPA-1a antigen leading to platelet destruction. In some cases, HPA-5b has also been implicated. It is unclear why alloantibodies attack the patient's own, as well as the introduced platelets. Probable explanation for this is that the recipient's platelet acquire the phenotype of donor's platelet by binding of the soluble antigens from the donor onto the recipient's platelet. It is usually self-limiting, but IVIG therapy is the primary treatment. Plasmapheresis is also an option for treatment.