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.

Although plasma exchange/infusion (PE/PI) is frequently used, there are no controlled trials of its safety or efficacy in aHUS. Even though PE/PI often partially controls some of the hematological manifestations of aHUS in some patients, its effectiveness has not been demonstrated in terms of inducing total disease remission. PE/PI is associated with significant safety risks, including risk of infection, allergic reactions, thrombosis, loss of vascular access, and poor quality of life. Importantly, terminal complement activation has been shown to be chronically present on the surface of platelets in patients with aHUS who appear to be clinically well while receiving chronic PE/PI.

Before the introduction of eculizumab (INN and USAN, trade name Soliris), a monoclonal antibody that is a first-in-class terminal complement inhibitor, management options for patients with aHUS were extremely limited. Guidelines issued by the European Paediatric Study Group for HUS recommend rapid administration of plasma exchange or plasma infusion (PE/PI), intensively administered daily for 5 days and then with reducing frequency. However, the American Society for Apheresis offers a "weak" recommendation for plasma exchange to treat aHUS, due to the "low" or "very low" quality of evidence supporting its use. Although some patients experienced improvements in red blood cell and platelet counts, plasma therapies generally did not result in full remission.

Due to the high mortality of untreated TTP, a presumptive diagnosis of TTP is made even when only microangiopathic hemolytic anemia and thrombocytopenia are seen, and therapy is started. Transfusion is contraindicated in thrombotic TTP, as it fuels the coagulopathy. Since the early 1990s, plasmapheresis has become the treatment of choice for TTP. This is an exchange transfusion involving removal of the patient's blood plasma through apheresis and replacement with donor plasma (fresh frozen plasma or cryosupernatant); the procedure must be repeated daily to eliminate the inhibitor and abate the symptoms. If apheresis is not available, fresh frozen plasma can be infused, but the volume that can be given safely is limited due to the danger of fluid overload. Plasma infusion alone is not as beneficial as plasma exchange. Corticosteroids (prednisone or prednisolone) are usually given. Rituximab, a monoclonal antibody aimed at the CD20 molecule on B lymphocytes, may be used on diagnosis; this is thought to kill the B cells and thereby reduce the production of the inhibitor. A stronger recommendation for rituximab exists where TTP does not respond to corticosteroids and plasmapheresis.

Caplacizumab is an alternative option in treating TTP as it has been shown that it induces a faster disease resolution compared with those patient who were on placebo. However, the use of caplacizumab was associated with increase bleeding tendencies in the studied subjects.

Most patients with refractory or relapsing TTP receive additional immunosuppressive therapy, e.g. vincristine, cyclophosphamide, splenectomy or a combination of the above.

Children with Upshaw-Schülman syndrome receive prophylactic plasma every two to three weeks; this maintains adequate levels of functioning ADAMTS13. Some tolerate longer intervals between plasma infusions. Additional plasma infusions may necessary for triggering events, such as surgery; alternatively, the platelet count may be monitored closely around these events with plasma being administered if the count drops.

Measurements of blood levels of lactate dehydrogenase, platelets, and schistocytes are used to monitor disease progression or remission. ADAMTS13 activity and inhibitor levels may be measured during follow-up, but in those without symptoms the use of rituximab is not recommended.

The course of treatment and the success rate is dependent on the type of TMA. Some patients with atypical HUS and TTP have responded to plasma infusions or exchanges, a procedure which replaces proteins necessary for the complement cascade that the patient does not have; however, this is not a permanent solution or treatment, especially for patients with congenital predispositions.

After birth, treatment depends on the severity of the condition, but could include temperature stabilization and monitoring, phototherapy, transfusion with compatible packed red blood, exchange transfusion with a blood type compatible with both the infant and the mother, sodium bicarbonate for correction of acidosis and/or assisted ventilation.

- Phototherapy - Phototherapy is used for cord bilirubin of 3 or higher. Some doctors use it at lower levels while awaiting lab results.

- IVIG - IVIG has been used to successfully treat many cases of HDN. It has been used not only on anti-D, but on anti-E as well. IVIG can be used to reduce the need for exchange transfusion and to shorten the length of phototherapy. The AAP recommends "In isoimmune hemolytic disease, administration of intravenousγ-globulin (0.5-1 g/kg over 2 hours) is recommended if the TSB is rising despite intensive phototherapy or the TSB level is within 2 to 3 mg/dL (34-51 μmol/L) of the exchange level . If necessary, this dose can be repeated in 12 hours (evidence quality B: benefits exceed harms). Intravenous γ-globulin has been shown to reduce the need for exchange transfusions in Rh and ABO hemolytic disease."

- Exchange transfusion - Exchange transfusion is used when bilirubin reaches either the high or medium risk lines on the nonogram provided by the American Academy of Pediatrics (Figure 4). Cord bilirubin >4 is also indicative of the need for exchange transfusion.

The mortality rate is around 95% for untreated cases, but the prognosis is reasonably favorable (80–90% survival) for patients with idiopathic TTP diagnosed and treated early with plasmapheresis.

The therapy of an acute TTP episode has to be started as early as possible. The standard treatment is the daily replacement of the missing ADAMTS13 protease in form of plasma infusions or in more severe episodes by plasma exchange. In the latter the patients plasma is replaced by donated plasma. The most common sources of ADAMTS13 is platelet-poor fresh frozen plasma (FFP) or solvent-detergent plasma.

The benefit of plasma exchange compared to plasma infusions alone may result from the additional removal of ULVWF. In general both plasma therapies are well tolerated, several mostly minor complications may be observed. The number of infusion/exchange sessions needed to overcome a TTP episode are variable but usually take less than a week in USS. The intensive plasma-therapy is generally stopped when platelet count increases to normal levels and is stable over several days.

In cases of Rho(D) incompatibility, Rho(D) immunoglobulin is given to prevent sensitization. However, there is no comparable immunotherapy available for other blood group incompatibilities.

Early pregnancy

- IVIG - IVIG stands for Intravenous Immunoglobulin. It is used in cases of previous loss, high maternal titers, known aggressive antibodies, and in cases where religion prevents blood transfusion. Ivig can be more effective than IUT alone. Fetal mortality was reduced by 36% in the IVIG and IUT group than in the IUT alone group. IVIG and plasmapheresis together can reduce or eliminate the need for an IUT.

- Plasmapheresis - Plasmapheresis aims to decrease the maternal titer by direct plasma replacement. Plasmapheresis and IVIG together can even be used on women with previously hydropic fetuses and losses.

Mid to late pregnancy

- IUT - Intrauterine Transfusion (IUT) is done either by intraperitoneal transfusion (IPT) or intravenous transfusion (IVT). IVT is preferred over IPT. IUTs are only done until 35 weeks. After that, the risk of an IUT is greater than the risk from post birth transfusion.

- Steroids - Steroids are sometimes given to the mother before IUTs and early delivery to mature the fetal lungs.

- Phenobarbital - Phenobarbital is sometimes given to the mother to help mature the fetal liver and reduce hyperbilirubinemia.

- Early Delivery - Delivery can occur anytime after the age of viability. Emergency delivery due to failed IUT is possible, along with induction of labor at 35–38 weeks.

Rhesus-negative mothers who have had a pregnancy who are pregnant with a rhesus-positive infant are offered Rho(D) immune globulin (RhIG) at 28 weeks during pregnancy, at 34 weeks, and within 48 hours after delivery to prevent sensitization to the D antigen. It works by binding any fetal red blood cells with the D antigen before the mother is able to produce an immune response and form anti-D IgG. A drawback to pre-partum administration of RhIG is that it causes a positive antibody screen when the mother is tested, which can be difficult to distinguish from natural immunological responses that result in antibody production. Without Rho(D) immunoglobulin, the risk of isoimmunization is approximately 17%; with proper administration the risk is reduced to less than 0.1-0.2%.

Acute renal failure occurs in 55–70% of patients with STEC-HUS, although up to 70–85% recover renal function. Patients with aHUS generally have poor outcomes, with up to 50% progressing to ESRD or irreversible brain damage; as many as 25% die during the acute phase. However, with aggressive treatment, more than 90% of patients survive the acute phase of HUS, and only about 9% may develop ESRD. Roughly one-third of persons with HUS have abnormal kidney function many years later, and a few require long-term dialysis. Another 8% of persons with HUS have other lifelong complications, such as high blood pressure, seizures, blindness, paralysis, and the effects of having part of their colon removed. The overall mortality rate from HUS is 5–15%. Children and the elderly have a worse prognosis.

Not all affected patients seem to need a regular preventive plasma infusion therapy, especially as some reach longterm remission without it. Regular plasma infusions are necessary in patients with frequent relapses and in general situations with increased risk to develop an acute episode (as seen above) such as pregnancy. Plasma infusions are given usually every two to three weeks to prevent acute episodes of USS but are often individually adapted.

Drug induced hemolysis has large clinical relevance. It occurs when drugs actively provoke red blood cell destruction. It can be divided in the following manner:

- Drug-induced autoimmune hemolytic anemia

- Drug-induced nonautoimmune hemolytic anemia

A total of four mechanisms are usually described, but there is some evidence that these mechanisms may overlap.

Acquired hemolytic anemia can be divided into immune and non-immune mediated forms of hemolytic anemia.

Once a woman has antibodies, she is at high risk for a transfusion reaction. For this reason, she must carry a medical alert card at all times and inform all doctors of her antibody status.

"Acute hemolytic transfusion reactions may be either immune-mediated or nonimmune-mediated. Immune-mediated hemolytic transfusion reactions caused by immunoglobulin M (IgM) anti-A, anti-B, or anti-A,B typically result in severe, potentially fatal complement-mediated intravascular hemolysis. Immune-mediated hemolytic reactions caused by IgG, Rh, Kell, Duffy, or other non-ABO antibodies typically result in extravascular sequestration, shortened survival of transfused red cells, and relatively mild clinical reactions. Acute hemolytic transfusion reactions due to immune hemolysis may occur in patients who have no antibodies detectable by routine laboratory procedures"

Summary of transfusion reactions in the US

Once a woman has antibodies, she is at high risk for a transfusion reaction. For this reason, she must carry a medical alert card at all times and inform all doctors of her antibody status.

"Acute hemolytic transfusion reactions may be either immune-mediated or nonimmune-mediated. Immune-mediated hemolytic transfusion reactions caused by immunoglobulin M (IgM) anti-A, anti-B, or anti-A,B typically result in severe, potentially fatal complement-mediated intravascular hemolysis. Immune-mediated hemolytic reactions caused by IgG, Rh, Kell, Duffy, or other non-ABO antibodies typically result in extravascular sequestration, shortened survival of transfused red cells, and relatively mild clinical reactions. Acute hemolytic transfusion reactions due to immune hemolysis may occur in patients who have no antibodies detectable by routine laboratory procedures."

Summary of transfusion reactions in the US.

There is no treatment for MKD. But, the inflammation and the other effects can be reduced to a certain extent.

- IL-1 targeting drugs can be used to reduce the effects of the disorder. Anakinra is antagonist to IL-1 receptors. Anakinra binds the IL-1 receptor, preventing the actions of both IL-1α and IL-1β, and it has been proved to reduce the clinical and biochemical inflammation in MKD. It can effectively decreases the frequency as well as the severity of inflammatory attacks when used on a daily basis. Disadvantages with the usage of this drug are occurrence of painful injection site reaction and as the drug is discontinued in the near future the febrile attacks start. (Examined in a 12-year-old patient).

- Canakinumab is a long acting monoclonal antibody which is directed against IL-1β has shown to be effective in reducing both frequency and severity in patients suffering from mild and severe MKD in case reports and observational case series. It reduces the physiological effects but the biochemical parameter still remain elevated (Galeotti et al. demonstrated that it is more effective than anakinra –considered 6 patients suffering from MKD).

- Anti-TNF therapy might be effective in MKD, but the effect is mostly partial and therapy failure and clinical deterioration have been described frequently in patients on infliximab or etanercept. A beneficial effect of human monoclonal anti-TNFα antibody adalimumab was seen in a small number of MKD patients.

- Most MKD patients are benefited by anti-IL-1 therapy. However, anti-IL-1-resistant disease may also occur. Example. tocilizumab (a humanized monoclonal antibody against the interleukin-6 (IL-6) receptor). This drug is used when the patients are unresponsive towards Anakinra. (Shendi et al. treated a young woman in whom anakinra was ineffective with tocilizumab). It was found that it was effective in reducing the biochemical and clinical inflammation [30].Stoffels et al. observed reduction of frequency and severity of the inflammatory attacks, although after several months of treatment one of these two patients persistently showed mild inflammatory symptoms in the absence of biochemical inflammatory markers.

- A beneficial effect of hematopoietic stem cell transplantation can be used in severe mevalonate kinase deficiency conditions (Improvement of cerebral myelinisation on MRI after allogenic stem cell transplantation was observed in one girl). But, liver transplantation did not influence febrile attacks in this patient.

In some cases, the direct coombs will be negative but severe, even fatal HDN can occur. An indirect coombs needs to be run in cases of anti-C, anti-c, and anti-M. Anti-M also recommends antigen testing to rule out the presence of HDN.

Antiemetic medications may be helpful for treating vomiting in children. Ondansetron has some utility, with a single dose being associated with less need for intravenous fluids, fewer hospitalizations, and decreased vomiting. Metoclopramide might also be helpful. However, the use of ondansetron might possibly be linked to an increased rate of return to hospital in children. The intravenous preparation of ondansetron may be given orally if clinical judgment warrants. Dimenhydrinate, while reducing vomiting, does not appear to have a significant clinical benefit.

Antibiotics are not usually used for gastroenteritis, although they are sometimes recommended if symptoms are particularly severe or if a susceptible bacterial cause is isolated or suspected. If antibiotics are to be employed, a macrolide (such as azithromycin) is preferred over a fluoroquinolone due to higher rates of resistance to the latter. Pseudomembranous colitis, usually caused by antibiotic use, is managed by discontinuing the causative agent and treating it with either metronidazole or vancomycin. Bacteria and protozoans that are amenable to treatment include "Shigella" "Salmonella typhi", and "Giardia" species. In those with "Giardia" species or "Entamoeba histolytica", tinidazole treatment is recommended and superior to metronidazole. The World Health Organization (WHO) recommends the use of antibiotics in young children who have both bloody diarrhea and fever.

Treatment is with penicillin, ampicillin, tetracycline, or co-trimoxazole for one to two years. Any treatment lasting less than a year has an approximate relapse rate of 40%. Recent expert opinion is that Whipple's disease should be treated with doxycycline with hydroxychloroquine for 12 to 18 months. Sulfonamides (sulfadiazine or sulfamethoxazole) may be added for treatment of neurological symptoms.

In some cases, the direct coombs will be negative but severe, even fatal HDN can occur. An indirect coombs needs to be run in cases of anti-C, anti-c, and anti-M. Anti-M also recommends antigen testing to rule out the presence of HDN.

Treatment is multifactorial. A diet very low in fat and high in high quality protein is essential. Treatment of humans can also involve the use of MCT (medium-chain triglycerides) oil and/or the drug octreotide. In dogs, fat soluble vitamins (A, D, E, and K) should be supplemented. Corticosteroid treatment may be required for life. Antibiotics can be used to treat bacterial overgrowth. With a very low serum albumin, transfusion with blood plasma or an infusion of hetastarch may be necessary to treat the signs until the diet can take effect. Lymphangiectasia is rarely cured but can remain in remission for a long time. It can be fatal when unresponsive to treatment.

Thrombotic microangiopathy (TMA) is a pathology that results in thrombosis in capillaries and arterioles, due to an endothelial injury. It may be seen in association with thrombocytopenia, anemia, purpura and renal failure.

The classic TMAs are hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. Other conditions with TMA include atypical hemolytic uremic syndrome, disseminated intravascular coagulation, scleroderma renal crisis, malignant hypertension,

antiphospholipid antibody syndrome, and drug toxicities, e.g. calcineurin inhibitor toxicity.

NMS is a medical emergency and can lead to death if untreated. The first step is to stop the antipsychotic medication and treat the hyperthermia aggressively, such as with cooling blankets or ice packs to the axillae and groin. Supportive care in an intensive care unit capable of circulatory and ventilatory support is crucial. The best pharmacological treatment is still unclear. Dantrolene has been used when needed to reduce muscle rigidity, and more recently dopamine pathway medications such as bromocriptine have shown benefit.

Amantadine is another treatment option due to its dopaminergic and anticholinergic effects.

Apomorphine may be used however its use is supported by little evidence. Benzodiazepines may be used to control . Highly elevated blood myoglobin levels can result in kidney damage, therefore aggressive intravenous hydration with diuresis may be required. When recognized early NMS can be successfully managed; however, up to 10% of cases can be fatal.

Should a patient subsequently require an antipsychotic, trialing a low dose of a low-potency atypical antipsychotic is recommended.

Depending on the severity, treatment involves either oral or intravenous antibiotics, using penicillins, clindamycin, or erythromycin. While illness symptoms resolve in a day or two, the skin may take weeks to return to normal.

Because of the risk of reinfection, prophylactic antibiotics are sometimes used after resolution of the initial condition. However, this approach does not always stop reinfection.