Although the rate of acute severe adverse cutaneous reactions to medications is low, these reactions can affect anyone who takes medications and can result in death or disability1. Even a small number of cases associated with a particular drug may alter the recommendations for its use2–4. Prompt differentiation of severe adverse cutaneous reactions from less serious skin disorders may be difficult. Rapid recognition of severe reactions is essential. Prompt withdrawal of the offending drug is often the most important action to minimize morbidity. Adverse cutaneous reactions to drugs are frequent, affecting 2 to 3 percent of hospitalized . . .

Severe Adverse Cutaneous Reactions to Drugs

Vasculitis is inflammation of vessel walls. It has many causes, although they result in only a few histologic patterns of vascular inflammation. Vessels of any type in any organ can be affected, a fact that results in a wide variety of signs and symptoms. These protean clinical manifestations, combined with the etiologic nonspecificity of the histologic lesions, complicate the diagnosis of specific forms of vasculitis. This is problematic because different vasculitides with indistinguishable clinical presentations have very different prognoses and treatments. For example, a patient with purpura, nephritis, and abdominal pain caused by Henoch–Schonlein purpura usually has a good prognosis . . .

https://www.nejm.org/doi/pdf/10.1056/NEJM199711203372106?listPDF=true

Small-Vessel Vasculitis

Antineutrophil cytoplasmic antibody (ANCA) tests are used to diagnose and monitor inflammatory activity in the primary systemic small vessel vasculitides. ANCA is best demonstrated in these diseases by using a combination of indirect immunofluorescence (IIF) of normal peripheral blood neutrophils and enzyme-linked immunosorbent assays (ELISAs) that detect ANCA specific for proteinase 3 (PR3) or myeloperoxidase (MPO). For ANCA testing in "new" patients, IIF must be performed on all serum samples. Serum samples containing ANCA, any other cytoplasmic fluorescence, or an antinuclear antibody (ANA) that results in homogeneous or peripheral nuclear fluorescence then should be tested in ELISAs for PR3-ANCA and MPO-ANCA. Optimally, ELISAs for PR3-ANCA and MPO-ANCA should be performed on all serum samples. Inclusion of the most recent positive sample in the IIF or ELISA may help demonstrate a change in antibody level. Reports should use recommended terms. Any report of positive neutrophil fluorescence issued before the ELISA results are available should indicate that positive fluorescence alone is not specific for the diagnosis of Wegener granulomatosis or microscopic polyangiitis and that decisions about treatment should not be based solely on the ANCA results.

/pdf/international-consensus-statement-on-testing-and-reporting-bbeslikp11.pdf

International Consensus Statement on Testing and Reporting of Antineutrophil Cytoplasmic Antibodies (ANCA)

http://medical-mastermind-community.com/uploads/ANCA-disease.pdf

The antineutrophil cytoplasmic antibody-associated vasculitides

The authors aimed to identify predictors of relapse and resistance to treatment in 350 patients with antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis. Patients had Wegener granuloma...

Rob Gans

Papers

Vasculitis and antineutrophil cytoplasmic autoantibodies associated with propylthiouracil therapy

Antiproteinase 3- and antimyeloperoxidase-associated vasculitis

Different immunological specificities and disease associations of c-ANCA and p-ANCA