People affected by the severest, often life-threatening, complications of cryoglobulinemic disease require urgent plasmapharesis and/or plasma exchange in order to rapidly reduce the circulating levels of their cryoglobulins. Complications commonly requiring this intervention include: hyperviscosity disease with severe symptoms of neurological (e.g. stroke, mental impairment, and myelitis) and/or cardiovascular (e.g., congestive heart failure, myocardial infarction) disturbances; vasculitis-driven intestinal ischemia, intestinal perforation, cholecystitis, or pancreatitis, causing acute abdominal pain, general malaise, fever, and/or bloody bowel movements; vasculitis-driven pulmonary disturbances (e.g. coughing up blood, acute respiratory failure, X-ray evidence of diffuse pulmonary infiltrates caused by diffuse alveolar hemorrhage); and severe kidney dysfunction due to intravascular deposition of immunoglobulins or vasculitis. Along with this urgent treatment, severely symptomatic patients are commonly started on therapy to treat any underlying disease; this treatment is often supplemented with anti-inflammatory drugs such as corticosteroids (e.g., dexamethasone) and/or immunosuppressive drugs. Cases where no underlying disease is known are also often treated with the latter corticosteroid and immunosuppressive medications.

Treatment of mixed cryoglobulinemic disease is, similar to type I disease, directed toward treating any underlying disorder. This includes malignant (particularly Waldenström's macroglobulinemia in type II disease), infectious, or autoimmune diseases in type II and III disease. Recently, evidence of hepatitis C infection has been reported in the majority of mixed disease cases with rates being 70-90% in areas with high incidences of hepatitis C. The most effective therapy for hepatitis C-associated cryoglobulinemic disease consists of a combination of anti-viral drugs, pegylated INFα and ribavirin; depletion of B cells using rituximab in combination with antiviral therapy or used alone in patients refractory to antiviral therapy has also proven successful in treating the hepatitis C-associated disease. Data on the treatment of infectious causes other than hepatitis C for the mixed disease are limited. A current recommendation treats the underlying disease with appropriate antiviral, anti-bacterial, or anti-fungal agents, if available; in cases refractory to an appropriate drug, the addition of immunosuppressive drugs to the therapeutic regimen may improve results. Mixed cryoglobulinemic disease associated with autoimmune disorders is treated with immunosuppressive drugs: combination of a corticosteroid with either cyclophosphamide, azathioprine, or mycophenolate or combination of a corticosteroid with rituximab have been used successfully to treated mixed disease associated with autoimmune disorders.

Studies on the treatment of cryofibrinoginemic disease have involved relatively few patients, are limited primarily to case reports, and differ based on whether the disease is primary or secondary. In all cases of cryofibrinogenemic disease, however, patients should avoid the exposure of afflicted body parts to cold weather or other environmental triggers of symptoms and avoid using cigarettes or other tobacco products. In severe cases, these individuals also risk developing serious thrombotic events which lead to tissue necrosis that may result in secondary bacterial infections and require intensive antimicrobial therapy and/or amputations. Careful treatment of these developments is required.

Treatment of secondary cryofibrinoginemic disease may use the same methods used for treating the primary disease wherever necessary but focus on treating the associated infectious, malignant, premalignant, vasculitis, or autoimmune disorder with the methods prescribed for the associated disorder. Case report studies suggest that: corticosteroids and immunosuppressive drug regimens, antimicrobial therapy, and anti-neoplastic regimens can be effective treatments for controlling the cryfibrinoginemic disease in cases associated respectively with autoimmune, infectious, and premalignant/malignant disorders.

Analgesics may be needed for the abdominal and joint pains. It is uncertain as to whether HSP needs treatment beyond controlling the symptoms. Most patients do not receive therapy because of the high spontaneous recovery rate. Steroids are generally avoided. However, if they are given early in the disease episode, the duration of symptoms may be shortened, and abdominal pain can improve significantly. Moreover, the chance of severe kidney problems may be reduced. A systematic review of randomized clinical trials did not find any evidence that steroid treatment (prednisone) is effective at decreasing the likelihood of developing long-term kidney disease.

Evidence of worsening kidney damage would normally prompt a kidney biopsy. Treatment may be indicated on the basis of the appearance of the biopsy sample; various treatments may be used, ranging from oral steroids to a combination of intravenous methylprednisolone (steroid), cyclophosphamide and dipyridamole followed by prednisone. Other regimens include steroids/azathioprine, and steroids/cyclophosphamide (with or without heparin and warfarin). Intravenous immunoglobulin (IVIG) is occasionally used.

There is no evidence from randomized clinical trials that treating children who have HSP with antiplatelet agent prevents persistent kidney disease. There is also no evidence from randomized clinical trials that treating children or adults with cyclophosphamide prevents severe kidney disease. Heparin treatment is not justified.

Treatment is targeted to the underlying cause. However, most vasculitis in general are treated with steroids (e.g. methylprednisolone) because the underlying cause of the vasculitis is due to hyperactive immunological damage. Immunosuppressants such as cyclophosphamide and azathioprine may also be given.

A systematic review of antineutrophil cytoplasmic antibody (ANCA) positive vasculitis identified best treatments depending on whether the goal is to induce remission or maintenance and depending on severity of the vasculitis.

Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to treat musculoskeletal symptoms. For individuals with severe complications, corticosteroids or immunosuppressive drugs may be prescribed, and sometimes IVIG (intravenous immunoglobulin). Also, disease-modifying antirheumatic drugs (DMARDs) such as methotrexate may be helpful. Hydroxychloroquine (Plaquenil) is another option and is generally considered safer than methotrexate. However, these prescribed drugs have a range of side effects such as nausea, loss of appetite, dizziness, hair loss, stomach aches/cramps, headache, liver toxicity, and increased risk of infections. Also, people who take drugs to suppress the immune system are more likely to develop cancer later.

For systemic symptoms, including fatigue, joint pain, myositis and neuropathy, biologic immunosuppressant drugs such as rituximab and belimumab that work via B-cell pathology are often used and have less toxic profiles than traditional immunosuppressive regimens.

Should treatment be started it should address both the paraprotein level and the lymphocytic B-cells.

In 2002, a panel at the International Workshop on Waldenström's Macroglobulinemia agreed on criteria for the initiation of therapy. They recommended starting therapy in patients with constitutional symptoms such as recurrent fever, night sweats, fatigue due to anemia, weight loss, progressive symptomatic lymphadenopathy or spleen enlargement, and anemia due to bone marrow infiltration. Complications such as hyperviscosity syndrome, symptomatic sensorimotor peripheral neuropathy, systemic amyloidosis, kidney failure, or symptomatic cryoglobulinemia were also suggested as indications for therapy.

Treatment includes the monoclonal antibody rituximab, sometimes in combination with chemotherapeutic drugs such as chlorambucil, cyclophosphamide, or vincristine or with thalidomide. Corticosteroids, such as prednisone, may also be used in combination. Plasmapheresis can be used to treat the hyperviscosity syndrome by removing the paraprotein from the blood, although it does not address the underlying disease. Ibrutinib is another agent that has been approved for use in this condition.

Recently, autologous bone marrow transplantation has been added to the available treatment options.

When primary or secondary resistance invariably develops, salvage therapy is considered. Allogeneic stem cell transplantation can induce durable remissions for heavily pre-treated patients.

The treatment of primary immunodeficiencies depends foremost on the nature of the abnormality. Somatic treatment of primarily genetic defects is in its infancy. Most treatment is therefore passive and palliative, and falls into two modalities: managing infections and boosting the immune system.

Reduction of exposure to pathogens may be recommended, and in many situations prophylactic antibiotics or antivirals may be advised.

In the case of humoral immune deficiency, immunoglobulin replacement therapy in the form of intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) may be available.

In cases of autoimmune disorders, immunosuppression therapies like corticosteroids may be prescribed.

First-line treatment for CIDP is currently intravenous immunoglobulin (IVIG) and other treatments include corticosteroids (e.g. prednisone), and plasmapheresis (plasma exchange) which may be prescribed alone or in combination with an immunosuppressant drug. Recent controlled studies show subcutaneous immunoglobin (SCIG) appears to be as effective for CIDP treatment as IVIG in most patients, and with fewer systemic side effects.

IVIG and plasmapheresis have proven benefit in randomized, double-blind, placebo-controlled trials. Despite less definitive published evidence of efficacy, corticosteroids are considered standard therapies because of their long history of use and cost effectiveness. IVIG is probably the first-line CIDP treatment, but is extremely expensive. For example, in the U.S., a single 65 g dose of Gamunex brand in 2010 might be billed at the rate of $8,000 just for the immunoglobulin—not including other charges such as nurse administration. Gamunex brand IVIG is the only U.S. FDA approved treatment for CIDP, as in 2008 Talecris, the maker of Gamunex, received orphan drug status for this drug for the treatment of CIDP.

Immunosuppressive drugs are often of the cytotoxic (chemotherapy) class, including rituximab (Rituxan) which targets B cells, and cyclophosphamide, a drug which reduces the function of the immune system. Ciclosporin has also been used in CIDP but with less frequency as it is a newer approach. Ciclosporin is thought to bind to immunocompetent lymphocytes, especially T-lymphocytes.

Non-cytotoxic immunosuppressive treatments usually include the anti-rejection transplant drugs azathioprine (Imuran/Azoran) and mycophenolate mofetil (Cellcept). In the U.S., these drugs are used as "off-label" treatments for CIDP, meaning that their use here is accepted by the FDA, but that CIDP treatment is not explicitly indicated or approved in the drug literature. Before azathioprine is used, the patient should first have a blood test that ensures that azathioprine can safely be used.

Anti-thymocyte globulin (ATG), an immunosuppressive agent that selectively destroys T lymphocytes is being studied for use in CIDP. Anti-thymocyte globulin is the gamma globulin fraction of antiserum from animals that have been immunized against human thymocytes. It is a polyclonal antibody.

Although chemotherapeutic and immunosuppressive agents have shown to be effective in treating CIDP, significant evidence is lacking, mostly due to the heterogeneous nature of the disease in the patient population in addition to the lack of controlled trials.

A review of several treatments found that azathioprine, interferon alpha and methotrexate were not effective. Cyclophosphamide and rituximab seem to have some response. Mycophenolate mofetil may be of use in milder cases. Immunoglobulin and steroids are the first line choices for treatment. Rarely bone marrow transplantation has been performed.

Physical therapy and occupational therapy may improve muscle strength, activities of daily living, mobility, and minimize the shrinkage of muscles and tendons and distortions of the joints.

In terms of management for complement deficiency, immunosuppressive therapy should be used depending on the disease presented. A C1-INH concentrate can be used for angio-oedema (C1-INH deficiency).

Pneumococcus and haemophilus infections prevention can be taken via immunization for those with complement deficiency. Epsilon-aminocaproic acid could be used to treat hereditary C1-INH deficiency, though the possible side effect of intravascular thrombosis should be weighed.

Antihistamines are not effective in treating the hives in this condition. It may respond to immunosuppressant drugs such as corticosteroids, cyclooxygenase inhibitors, interferon alpha, interleukin 1 receptor antagonists (Anakinra), perfloxacin, colchicine, cyclosporine or thalidomide. The hives may respond to treatment with PUVA, and the bone pain may respond to bisphosphonates.

Because Schnitzler's syndrome is so rare, the efficacy of different treatments cannot be compared using statistics. Nevertheless, case studies provide evidence that anakinra (otherwise known as kineret) is much more effective for Schnitzler's syndrome than any other drug, and that the improvement in symptoms associated with this treatment is dramatic. For example, Beseda and Nossent (2010) reviewed the literature concerning IL1-RA treatment (i.e. anakinra) for Schnitzler's syndrome. They concluded that, “Twenty-four patients with Schnitzler's syndrome... have been successfully treated with anakinra.” They add that “seven out of seven patients [with Schnitzler’s syndrome], that either interrupted or used anakinra every other day, had relapse of their symptoms within 24-48 h; anakinra was restarted in all patients with the same clinical efficiency.” Kluger et al. (2008) investigated the effectiveness of anakinra for a range of conditions. They searched MEDLINE for English-language trials of anakinra and abstracts from rheumatologial scientific meetings. They conclude that, “Over the last few years it has become increasingly evident that anakinra is highly effective and safe in patients with ... Schnitzler’s syndrome”. The year before, De Koning et al. (2007) reviewed the disease characteristics of Schnitzler syndrome and collected follow-up information to gain insight into long-term prognosis and treatment efficacy. They used data from 94 patients, and their conclusions about treatment for the condition are that, “There have been promising developments in therapeutic options, especially antiinterleukin-1 treatment, which induced complete remission in all 8 patients treated so far.”

Reports of individual patients treated with anakinra illustrate its effectiveness. Beseda and Nossent (ibid.) report treating a longstanding multidrug resistant Schnitzler’s syndrome patient with anakinra: “Within 24 h after the first injection, both the urticaria and the fever disappeared and have not recurred. For the past 6 months, the patient has been in clinical and biochemical remission.” Other authors report “a complete resolution of symptoms” (Dybowski et al., 2008). Crouch et al. (2007) report the effective treatment of a 52-year-old man who had been diagnosed with Schnitzler’s syndrome 8 years earlier: “On review, one week later, the patient’s systemic symptoms had resolved, and his previously elevated white cell count and inflammatory markers had normalised. The use of anakinra in our patient resulted in resolution of symptoms and has enabled cessation of oral prednisolone. Our patient remains symptom free on anakinra after 14 months of follow-up”. Similar stories are reported by Frischmeyer-Guerrerio et al. (2008), Wastiaux et al. (2007), and Eiling et al. (2007), Schneider et al. (2007). De Koning et al. (2006) treated three patients with Schnitzler’s syndrome with thalidomide and anakinra. Thalidomide was only effective for one of the three patients and was discontinued because of polyneuropathy. In contrast, for all three patients, anakinra “led to disappearance of fever and skin lesions within 24 hours. After a follow-up of 16-18 months, all patients are free of symptoms”. The authors concluded that anakinra as a treatment for Schnitzler’s syndrome “is preferable to thalidomide... as it has fewer side effects”.

As well as being more effective, anakinra is safer than the other treatments available for Schnitzler's syndrome. The Cochrane review entitled, ‘Anakinra for rheumatoid arthritis’ (Mertens and Singh, 2009 ) evaluates the (clinical effectiveness and) safety of anakinra in adult patients with rheumatoid arthritis, using data from 2876 patients, from five trials which constituted 781 randomized to placebo and 2065 to anakinra. The authors conclude, “There were no statistically significant differences noted in most safety outcomes with treatment with anakinra versus placebo - including number of withdrawals, deaths, adverse events (total and serious), and infections (total and serious). Injection site reactions were significantly increased, occurring in 1235/1729 (71%) versus 204/729 (28%) of patients treated with anakinra versus placebo, respectively”. These injection site reactions last for no more than four months, and are trivial compared to the very debilitating symptoms of Schnitzler's syndrome.

Bone marrow transplant may be possible for Severe Combined Immune Deficiency and other severe immunodeficiences.

Virus-specific T-Lymphocytes (VST) therapy is used for patients who have received hematopoietic stem cell transplantation that has proven to be unsuccessful. It is a treatment that has been effective in preventing and treating viral infections after HSCT. VST therapy uses active donor T-cells that are isolated from alloreactive T-cells which have proven immunity against one or more viruses. Such donor T-cells often cause acute graft-versus-host disease (GVHD), a subject of ongoing investigation. VSTs have been produced primarily by ex-vivo cultures and by the expansion of T-lymphocytes after stimulation with viral antigens. This is carried out by using donor-derived antigen-presenting cells. These new methods have reduced culture time to 10–12 days by using specific cytokines from adult donors or virus-naive cord blood. This treatment is far quicker and with a substantially higher success rate than the 3–6 months it takes to carry out HSCT on a patient diagnosed with a primary immunodeficiency. T-lymphocyte therapies are still in the experimental stage; few are even in clinical trials, none have been FDA approved, and availability in clinical practice may be years or even a decade or more away.

Medications can be helpful for moderate or severe RP.

- Vasodilators – calcium channel blockers, such as the dihydropyridines nifedipine or amlodipine, preferably slow release preparations – are often first line treatment. They have the common side effects of headache, flushing, and ankle edema; but these are not typically of sufficient severity to require cessation of treatment. The limited evidence available shows that calcium channel blockers are only slightly effective in reducing how often the attacks happen. Peoples whose RP is secondary to erythromelalgia often cannot use vasodilators for therapy as they trigger 'flares' causing the extremities to become burning red due to there being too much blood.

- People with severe RP prone to ulceration or large artery thrombotic events may be prescribed aspirin.

- Sympatholytic agents, such as the alpha-adrenergic blocker prazosin, may provide temporary relief.

- Losartan can, and topical nitrates may, reduce the severity and frequency of attacks, and the phosphodiesterase inhibitors sildenafil and tadalafil may reduce their severity.

- Angiotensin receptor blockers or ACE inhibitors may aid blood flow to the fingers, and there is some evidence that angiotensin receptor blockers (often losartan) reduce frequency and severity of attacks, and possibly better than nifedipine.

- The prostaglandin iloprost is used to manage critical ischemia and pulmonary hypertension in RP, and the endothelin receptor antagonist bosentan is used to manage severe pulmonary hypertension and prevent finger ulcers in scleroderma.

- Statins have a protective effect on blood vessels, and SSRIs such as fluoxetine may help RP symptoms but the data is weak.

Evidence does not support the use of alternative medicine, including acupuncture and laser therapy.

Overall prognosis is good in most patients, with one study showing recovery occurring in 94% and 89% of children and adults, respectively (some having needed treatment). In children under ten, the condition recurs in about a third of all cases and usually within the first four months after the initial attack. Recurrence is more common in older children and adults.

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.

Autoimmune polyendocrine syndrome type 1 treatment is based on the symptoms that are presented by the affected individual, additionally there is:

- Hormone replacement

- Systemic antifungal treatment

- Immunosuppressive treatment

Paraproteinemias may be categorized according to the type of monoclonal protein found in blood:

- Light chains only (or Bence Jones protein). This may be associated with multiple myeloma or AL amyloidosis.

- Heavy chains only (also known as "heavy chain disease");

- Whole immunoglobulins. In this case, the paraprotein goes under the name of "M-protein" ("M" for monoclonal). If immunoglobulins tend to precipitate within blood vessels with cold, that phenomenon takes the name of cryoglobulinaemia.

The three types of paraproteins may occur alone or in combination in a given individual. Note that while most heavy chains or whole immunoglobulins remain within blood vessels, light chains frequently escape and are excreted by the kidneys into urine, where they take the name of Bence Jones protein.

It is also possible for paraproteins (usually whole immunoglobulins) to form polymers by aggregating with each other; this takes the name of macroglobulinemia and may lead to further complications. For example, certain macroglobulins tend to precipitate within blood vessel with cold, a phenomenon known as cryoglobulinemia. Others may make blood too viscous to flow smoothly (usually with IgM pentamer macroglobulins), a phenomenon known as Waldenström macroglobulinemia.

Treatment with antiviral medication is recommended in all people with proven chronic hepatitis C who are not at high risk of dying from other causes. People with the highest complication risk should be treated first, with the risk of complications based on the degree of liver scarring. The initial recommended treatment depends on the type of hepatitis C virus and whether or not a person has cirrhosis.

- HCV genotype 1a (no cirrhosis): 12 weeks of elbasvir/grazoprevir, ledipasvir/sofosbuvir, or sofosbuvir/velpatasvir. Sofosbuvir with either daclatasvir or simeprevir may also be used.

- HCV genotype 1a (with cirrhosis): 12 weeks of elbasvir/grazoprevir, ledipasvir/sofosbuvir, or sofosbuvir/velpatasvir.

- HCV genotype 1b (no cirrhosis): 12 weeks of elbasvir/grazoprevir, ledipasvir/sofosbuvir, or sofosbuvir/velpatasvir. Sofosbuvir with either daclatasvir or simeprevir may also be used.

- HCV genotype 1b (with cirrhosis): 12 weeks of elbasvir/grazoprevir, ledipasvir/sofosbuvir, or sofosbuvir/velpatasvir.

- HCV genotype 2 (with or without cirrhosis): 12 weeks of sofosbuvir/velpatasvir.

- HCV genotype 3 (no cirrhosis): 12 weeks of sofosbuvir/velpatasvir or daclatasvir and sofosbuvir.

- HCV genotype 3 (with cirrhosis): 12 weeks of sofosbuvir/velpatasvir or 24 weeks of daclatasvir and sofosbuvir.

- HCV genotype 4 (with and without cirrhosis): 12 weeks of elbasvir/grazoprevir, ledipasvir/sofosbuvir, or sofosbuvir/velpatasvir.

- HCV genotype 5 or 6: 12 weeks of sofosbuvir/velpatasvir or ledipasvir/sofosbuvir.

Chronic infection can be cured about 95% of the time with recommended treatment in 2017. Getting access to these treatments however can be expensive. The combination of sofosbuvir, velpatasvir, and voxilaprevir may be used in those who have previously been treated with sofosbuvir or other drugs that inhibit NS5A and were not cured.

Prior to 2011, treatments consisted of a combination of pegylated interferon alpha and ribavirin for a period of 24 or 48 weeks, depending on HCV genotype. This produces cure rates of between 70 and 80% for genotype 2 and 3, respectively, and 45 to 70% for genotypes 1 and 4. Adverse effects with these treatments were common, with half of people getting flu like symptoms and a third experiencing emotional problems. Treatment during the first six months is more effective than once has become chronic.

Paraproteinemia, also known as monoclonal gammopathy, is the presence of excessive amounts of paraprotein or single monoclonal gammaglobulin in the blood. It is usually due to an underlying immunoproliferative disorder or hematologic neoplasms, especially multiple myeloma. It is sometimes considered equivalent to plasma cell dyscrasia.

Several alternative therapies are claimed by their proponents to be helpful for including milk thistle, ginseng, and colloidal silver. However, no alternative therapy has been shown to improve outcomes in , and no evidence exists that alternative therapies have any effect on the virus at all.

Vasculitis secondary to connective tissue disorders. Usually secondary to systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), relapsing polychondritis, Behçet's disease, and other connective tissue disorders.

Vasculitis secondary to viral infection. Usually due to hepatitis B and C, HIV, cytomegalovirus, Epstein-Barr virus, and Parvo B19 virus.