No specific cure is known. Treatment is largely supportive. Nonsteroidal anti-inflammatory drugs (NSAIDs) are indicated for tender lymph nodes and fever, and corticosteroids are useful in severe extranodal or generalized disease.

Symptomatic measures aimed at relieving the distressing local and systemic complaints have been described as the main line of management of KFD. Analgesics, antipyretics, NSAIDs, and corticosteroids have been used. If the clinical course is more severe, with multiple flares of bulky enlarged cervical lymph nodes and fever, then a low-dose corticosteroid treatment has been suggested.

Systemic corticosteroids such as (prednisone) can produce rapid improvement and are the “gold standard” for treatment. The temperature, white blood cell count, and eruption improve within 72 hours. The skin lesions clear within 3 to 9 days. Abnormal laboratory values rapidly return to normal. There are, however, frequent recurrences. Corticosteroids are tapered within 2 to 6 weeks to zero.

Resolution of the eruption is occasionally followed by milia and scarring. The disease clears spontaneously in some patients. Topical and/or intralesional corticosteroids may be effective as either monotherapy or adjuvant therapy.

Oral potassium iodide or colchicine may induce rapid resolution.

Patients who have a potential systemic infection or in whom corticosteroids are contraindicated can use these agents as a first-line therapy.

In one study, indomethacin, 150 mg per day, was given for the first week, and 100 mg per day was given for 2 additional weeks. Seventeen of 18 patients had a good initial response; fever and arthralgias were markedly attenuated within 48 hours, and eruptions cleared between 7 and 14 days.

Patients whose cutaneous lesions continued to develop were successfully treated with prednisone (1 mg/kg per day). No patient had a relapse after discontinuation of indomethacin.

Other alternatives to corticosteroid treatment include dapsone, doxycycline, clofazimine, and cyclosporine. All of these drugs influence migration and other functions of neutrophils.

Incision drainage with proper evacuation of the fluid followed by anti-tubercular medication.

Lucio's phenomenon is treated by anti-leprosy therapy (dapsone, rifampin, and clofazimine), optimal wound care, and treatment for bacteremia including antibiotics. In severe cases exchange transfusion may be helpful.

Guidelines for management of patients up to 18 years with Langerhans cell histiocytosis has been suggested. Treatment is guided by extent of disease. Solitary bone lesion may be amenable through excision or limited radiation, dosage of 5-10 Gys for children, 24-30 Gys for adults. However systemic diseases often require chemotherapy. Use of systemic steroid is common, singly or adjunct to chemotherapy. Local steroid cream is applied to skin lesions. Endocrine deficiency often require lifelong supplement e.g. desmopressin for diabetes insipidus which can be applied as nasal drop. Chemotherapeutic agents such as alkylating agents, antimetabolites, vinca alkaloids either singly or in combination can lead to complete remission in diffuse disease.

Children with Kawasaki disease should be hospitalized and cared for by a physician who has experience with this disease. When in an academic medical center, care is often shared between pediatric cardiology, pediatric rheumatology, and pediatric infectious disease specialists (although no specific infectious agent has been identified as yet). Treatment should be started as soon as the diagnosis is made to prevent damage to the coronary arteries.

Intravenous immunoglobulin (IVIG) is the standard treatment for Kawasaki disease and is administered in high doses with marked improvement usually noted within 24 hours. If the fever does not respond, an additional dose may have to be considered. In rare cases, a third dose may be given to the child. IVIG by itself is most useful within the first seven days of onset of fever, in terms of preventing coronary artery aneurysm.

Salicylate therapy, particularly aspirin, remains an important part of the treatment (though questioned by some) but salicylates alone are not as effective as IVIG. Aspirin therapy is started at high doses until the fever subsides, and then is continued at a low dose when the patient returns home, usually for two months to prevent blood clots from forming. Except for Kawasaki disease and a few other indications, aspirin is otherwise normally not recommended for children due to its association with Reye's syndrome. Because children with Kawasaki disease will be taking aspirin for up to several months, vaccination against varicella and influenza is required, as these infections are most likely to cause Reye's syndrome.

High-dose aspirin is associated with anemia and does not confer benefit to disease outcomes.

Corticosteroids have also been used, especially when other treatments fail or symptoms recur, but in a randomized controlled trial, the addition of corticosteroid to immune globulin and aspirin did not improve outcome. Additionally, corticosteroid use in the setting of Kawasaki disease is associated with increased risk of coronary artery aneurysm, so its use is generally contraindicated in this setting. In cases of Kawasaki disease refractory to IVIG, cyclophosphamide and plasma exchange have been investigated as possible treatments, with variable outcomes.

Kikuchi disease or Kikuchi-Fujimoto disease was described in 1972 in Japan. It is also known as histiocytic necrotizing lymphadenitis, Kikuchi necrotizing lymphadenitis, phagocytic necrotizing lymphadenitis, subacute necrotizing lymphadenitis, and necrotizing lymphadenitis.

It was first described by Dr Masahiro Kikuchi (1935–2012) in 1972 and independently by Y. Fujimoto.

Treatment with chemotherapy has been used with some success, particularly using lomustine, prednisone, doxorubicin, and cyclophosphamide. Because of the rapid progression of this aggressive disease, the prognosis is very poor.

Surgical debridement (cutting away affected tissue) is the mainstay of treatment for necrotizing fasciitis. Early medical treatment is often presumptive; thus, antibiotics should be started as soon as this condition is suspected. Given the dangerous nature of the disease, a high index of suspicion is needed. Initial treatment often includes a combination of intravenous antibiotics including piperacillin/tazobactam, vancomycin, and clindamycin. Cultures are taken to determine appropriate antibiotic coverage, and antibiotics may be changed when culture results are obtained.

Treatment for necrotizing fasciitis may involve an interdisciplinary care team. For example, in the case of a necrotizing fasciitis involving the head and neck, the team could include otolaryngologists, speech pathologists, intensivists, infectious disease specialists, and plastic surgeons or oral and maxillofacial surgeons. Maintaining strict asepsis during any surgical procedure and regional anaesthesia techniques is vital in preventing the occurrence of the disease.

Excellent for single-focus disease. With multi-focal disease 60% have a chronic course, 30% achieve remission and mortality is up to 10%.

In very severe cases of necrotizing scleritis, eye surgery must be performed to repair damaged corneal tissue in the eye and preserve the patient's vision. For less severe cases, nonsteroidal anti-inflammatory drugs, such as ibuprofen, are prescribed for pain relief. Scleritis itself is treated with an oral medication containing corticosteroids and an eye solution. In some cases, antibiotics are prescribed. Simply using eye drops will not treat scleritis. In more aggressive cases of scleritis, chemotherapy (such as systemic immunosuppressive therapy with such drugs as cyclophosphamide or azathioprine) may be used to treat the disease. If not treated, scleritis can cause blindness.

Hyperbaric oxygen treatment is sometimes used to treat necrotizing soft tissue infection in combination with antibiotics and debridement, but there is a lack of compelling evidence regarding its efficacy for this purpose.

Pain medication such as NSAIDs and paracetamol (acetaminophen) helps in the management of pain associated with strep throat. Viscous lidocaine may also be useful. While steroids may help with the pain, they are not routinely recommended. Aspirin may be used in adults but is not recommended in children due to the risk of Reye syndrome.

Untreated streptococcal pharyngitis usually resolves within a few days. Treatment with antibiotics shortens the duration of the acute illness by about 16 hours. The primary reason for treatment with antibiotics is to reduce the risk of complications such as rheumatic fever and retropharyngeal abscesses; antibiotics are effective if given within 9 days of the onset of symptoms.

There is no clearly defined cure for necrobiosis. NLD may be treated with PUVA therapy and improved therapeutic control.

Although there are some techniques that can be used to diminish the signs of necrobiosis such as low dose aspirin orally, a steroid cream or injection into the affected area, this process may be effective for only a small percentage of those treated.

It is not lethal in nature and is responsive to tetracycline or ciprofloxacin. Surgical treatment include rhinoplasty. However, if left untreated the disease can lead to sepsis, bleeding, or other chronic conditions that can be fatal.

Treatment involves antibiotics and may involve drainage of the buboes or abscesses by needle aspiration or incision. Further supportive measure may need to be taken: dilatation of the rectal stricture, repair of rectovaginal fistulae, or colostomy for rectal obstruction.

Common antibiotic treatments include: tetracycline (doxycycline) (all tetracyclines, including doxycycline, are contraindicated during pregnancy and in children due to effects on bone development and tooth discoloration), and erythromycin. Azithromycin is also a drug of choice in LGV.

People with AIDS are given macrolide antibiotics such as azithromycin for prophylactic treatment.

People with HIV infection and less than 50 CD4+ T-lymphocytes/uL should be administered prophylaxis against MAC. Prophylaxis should be continued for the patient's lifetime unless multiple drug therapy for MAC becomes necessary because of the development of MAC disease.

Clinicians must weigh the potential benefits of MAC prophylaxis against the potential for toxicities and drug interactions, the cost, the potential to produce resistance in a community with a high rate of tuberculosis, and the possibility that the addition of another drug to the medical regimen may adversely affect patients' compliance with treatment. Because of these concerns, therefore, in some situations rifabutin prophylaxis should not be administered.

Before prophylaxis is administered, patients should be assessed to ensure that they do not have active disease due to MAC, M. tuberculosis, or any other mycobacterial species. This assessment may include a chest radiograph and tuberculin skin test.

Rifabutin, by mouth daily, is recommended for the people's lifetime unless disseminated MAC develops, which would then require multiple drug therapy. Although other drugs, such as azithromycin and clarithromycin, have laboratory and clinical activity against MAC, none has been shown in a prospective, controlled trial to be effective and safe for prophylaxis. Thus, in the absence of data, no other regimen can be recommended at this time.The 300-mg dose of rifabutin has been well tolerated. Adverse effects included neutropenia, thrombocytopenia, rash, and gastrointestinal disturbances.

As with all STIs, sex partners of patients who have LGV should be examined and tested for urethral or cervical chlamydial infection. After a positive culture for chlamydia, clinical suspicion should be confirmed with testing to distinguish serotype. Antibiotic treatment should be started if they had sexual contact with the patient during the 30 days preceding onset of symptoms in the patient. Patients with a sexually transmitted disease should be tested for other STDs due to high rates of comorbid infections. Antibiotics are not without risks and prophylaxtic broad antibiotic coverage is not recommended.

Postinfection treatment involves a combination of antituberculosis antibiotics, including rifampicin, rifabutin, ciprofloxacin, amikacin, ethambutol, streptomycin, clarithromycin or azithromycin.

NTM infections are usually treated with a three-drug regimen of either clarithromycin or azithromycin, plus rifampicin and ethambutol. Treatment typically lasts at least 12 months.

Although studies have not yet identified an optimal regimen or confirmed that any therapeutic regimen produces sustained clinical benefit for patients with disseminated MAC, the Task Force concluded that the available information indicated the need for treatment of disseminated MAC. The Public Health Service therefore recommends that regimens be based on the following principles:

- Treatment regimens outside a clinical trial should include at least two agents.

- Every regimen should contain either azithromycin or clarithromycin; many experts prefer ethambutol as a second drug. Many clinicians have added one or more of the following as second, third, or fourth agents: clofazimine, rifabutin, rifampin, ciprofloxacin, and in some situations amikacin. Isoniazid and pyrazinamide are not effective for the therapy of MAC.

- Therapy should continue for the lifetime of the patient if clinical and microbiologic improvement is observed.

Clinical manifestations of disseminated MAC—such as fever, weight loss, and night sweats—should be monitored several times during the initial weeks of therapy. Microbiologic response, as assessed by blood culture every 4 weeks during initial therapy, can also be helpful in interpreting the efficacy of a therapeutic regimen.Most patients who ultimately respond show substantial clinical improvement in the first 4–6 weeks of therapy. Elimination of the organisms from blood cultures may take somewhat longer, often requiring 4–12 weeks.

With early treatment, rapid recovery from the acute symptoms can be expected, and the risk of coronary artery aneurysms is greatly reduced. Untreated, the acute symptoms of Kawasaki disease are self-limited ("i.e." the patient will recover eventually), but the risk of coronary artery involvement is much greater. Overall, about 2% of patients die from complications of coronary vasculitis. Patients who have had Kawasaki disease should have an echocardiogram initially every few weeks, and then every one or two years to screen for progression of cardiac involvement.

Laboratory evidence of increased inflammation combined with demographic features (male sex, age less than six months or greater than eight years) and incomplete response to IVIG therapy create a profile of a high-risk patient with Kawasaki disease. The likelihood that an aneurysm will resolve appears to be determined in large measure by its initial size, in which the smaller aneurysms have a greater likelihood of regression. Other factors are positively associated with the regression of aneurysms, including being younger than a year old at the onset of Kawasaki disease, fusiform rather than saccular aneurysm morphology, and an aneurysm location in a distal coronary segment. The highest rate of progression to stenosis occurs among those who develop large aneurysms. The worst prognosis occurs in children with giant aneurysms. This severe outcome may require further treatment such as percutaneous transluminal angioplasty, coronary artery stenting, bypass grafting, and even cardiac transplantation.

A relapse of symptoms may occur soon after initial treatment with IVIG. This usually requires rehospitalization and retreatment. Treatment with IVIG can cause allergic and nonallergic acute reactions, aseptic meningitis, fluid overload and, rarely, other serious reactions. Overall, life-threatening complications resulting from therapy for Kawasaki disease are exceedingly rare, especially compared with the risk of nontreatment. Also, evidence indicates Kawasaki disease produces altered lipid metabolism that persists beyond the clinical resolution of the disease.

If a patient is resistant to either cladribine or pentostatin, then second-line therapy is pursued.

Monoclonal antibodies The most common treatment for cladribine-resistant disease is infusing monoclonal antibodies that destroy cancerous B cells. Rituximab is by far the most commonly used. Most patients receive one IV infusion over several hours each week for four to eight weeks. A 2003 publication found two partial and ten complete responses out of 15 patients with relapsed disease, for a total of 80% responding. The median patient (including non-responders) did not require further treatment for more than three years. This eight-dose study had a higher response rate than a four-dose study at Scripps, which achieved only 25% response rate. Rituximab has successfully induced a complete response in Hairy Cell-Variant.

Rituximab's major side effect is serum sickness, commonly described as an "allergic reaction", which can be severe, especially on the first infusion. Serum sickness is primarily caused by the antibodies clumping during infusion and triggering the complement cascade. Although most patients find that side effects are adequately controlled by anti-allergy drugs, some severe, and even fatal, reactions have occurred. Consequently, the first dose is always given in a hospital setting, although subsequent infusions may be given in a physician's office. Remissions are usually shorter than with the preferred first-line drugs, but hematologic remissions of several years' duration are not uncommon.

Other B cell-destroying monoclonal antibodies such as Alemtuzumab, Ibritumomab tiuxetan and I-131 Tositumomab may be considered for refractory cases.

Interferon-alpha Interferon-alpha is an immune system hormone that is very helpful to a relatively small number of patients, and somewhat helpful to most patients. In about 65% of patients, the drug helps stabilize the disease or produce a slow, minor improvement for a partial response.

The typical dosing schedule injects at least 3 million units of Interferon-alpha (not pegylated versions) three times a week, although the original protocol began with six months of daily injections.

Some patients tolerate IFN-alpha very well after the first couple of weeks, while others find that its characteristic flu-like symptoms persist. About 10% of patients develop a level of depression. It is possible that, by maintaining a steadier level of the hormone in the body, that daily injections might cause fewer side effects in selected patients. Drinking at least two liters of water each day, while avoiding caffeine and alcohol, can reduce many of the side effects.

A drop in blood counts is usually seen during the first one to two months of treatment. Most patients find that their blood counts get worse for a few weeks immediately after starting treatment, although some patients find their blood counts begin to improve within just two weeks.

It typically takes six months to figure out whether this therapy is useful. Common criteria for treatment success include:

- normalization of hemoglobin levels (above 12.0 g/dL),

- a normal or somewhat low platelet count (above 100 K/µL), and

- a normal or somewhat low absolute neutrophil count (above 1.5 K/µL).

If it is well tolerated, patients usually take the hormone for 12 to 18 months. An attempt may be made then to end the treatment, but most patients discover that they need to continue taking the drug for it to be successful. These patients often continue taking this drug indefinitely, until either the disease becomes resistant to this hormone, or the body produces an immune system response that limits the drug's ability to function. A few patients are able to achieve a sustained clinical remission after taking this drug for six months to one year. This may be more likely when IFN-alpha has been initiated shortly after another therapy. Interferon-alpha is considered the drug of choice for pregnant women with active HCL, although it carries some risks, such as the potential for decreased blood flow to the placenta.

Interferon-alpha works by sensitizing the hairy cells to the killing effect of the immune system hormone TNF-alpha, whose production it promotes. IFN-alpha works best on classic hairy cells that are not protectively adhered to vitronectin or fibronectin, which suggests that patients who encounter less fibrous tissue in their bone marrow biopsies may be more likely to respond to Interferon-alpha therapy. It also explains why non-adhered hairy cells, such as those in the bloodstream, disappear during IFN-alpha treatment well before reductions are seen in adhered hairy cells, such as those in the bone marrow and spleen.

Splenectomy can produce long-term remissions in patients whose spleens seem to be heavily involved, but its success rate is noticeably lower than cladribine or pentostatin. Splenectomies are also performed for patients whose persistently enlarged spleens cause significant discomfort or in patients whose persistently low platelet counts suggest Idiopathic thrombocytopenic purpura.

Bone marrow transplants are usually shunned in this highly treatable disease because of the inherent risks in the procedure. They may be considered for refractory cases in younger, otherwise healthy individuals. "Mini-transplants" are possible.

People with anemia or thrombocytopenia may also receive red blood cells and platelets through blood transfusions. Blood transfusions are always irradiated to remove white blood cells and thereby reduce the risk of graft-versus-host disease. Patients may also receive a hormone to stimulate production of red blood cells. These treatments may be medically necessary, but do not kill the hairy cells.

People with low neutrophil counts may be given filgrastim or a similar hormone to stimulate production of white blood cells. However, a 1999 study indicates that routine administration of this expensive injected drug has no practical value for HCL patients after cladribine administration. In this study, patients who received filgrastim were just as likely to experience a high fever and to be admitted to the hospital as those who did not, even though the drug artificially inflated their white blood cell counts. This study leaves open the possibility that filgrastim may still be appropriate for patients who have symptoms of infection, or at times other than shortly after cladribine treatment.

Although hairy cells are technically long-lived, instead of rapidly dividing, some late-stage patients are treated with broad-spectrum chemotherapy agents such as methotrexate that are effective at killing rapidly dividing cells. This is not typically attempted unless all other options have been exhausted and it is typically unsuccessful.

Most histiocytomas will regress within two or three months. Surgical removal may be necessary if the tumor does not regress or if it is growing rapidly to a large size. Histiocytomas should never be treated with an intralesional injection of a corticosteroid, as remission relies on recognition of the tumour by the body's immune system which is suppressed by steroids.

Sweet's syndrome (SS), or acute febrile neutrophilic dermatosis is a skin disease characterized by the sudden onset of fever, an elevated white blood cell count, and tender, red, well-demarcated papules and plaques that show dense infiltrates by neutrophil granulocytes on histologic examination.

The syndrome was first described in 1964 by Robert Douglas Sweet. It was also known as Gomm-Button disease in honour of the first two patients Sweet diagnosed with the condition.