In countries with a high prevalence of tuberculosis, the presence of autoantibodies in a patient with vasculitis, fever, and pulmonary cavitation requires investigation of infectious causes. illness is pulmonary; however, more than 10% of instances have an extrapulmonary demonstration.1, 2 While the incidence of tuberculosis (TB) has been increasing worldwide, this affects the event of atypical forms. Pores and skin lesions Colec10 associated with TB are highly polymorphic, and may occur by direct action of bacilli, by inoculation, hematogenous propagation, deposition of immune complexes within Sodium sulfadiazine the walls of small vessels (hypersensitivity vasculitis), or by the formation of antibodies against antigens in the sponsor.3, 4, 5 Small vessel vasculitis secondary to TB is uncommon, with less than 20 instances reported in the literature. propagation, deposition of immune complexes within the walls of small vessels (hypersensitivity vasculitis), or by the formation of antibodies against antigens in the sponsor.3, 4, 5 Small vessel vasculitis secondary to TB is uncommon, with less than 20 instances reported in the literature. Three forms have been explained: Henoch-Sch?nlein purpura, vasculitis secondary to rifampicin, and cutaneous leukocytoclastic vasculitis.1, 3, 6 TB can occur associated with additional autoimmune diseases, such as WG, posting related clinical findings and histopathology.2, 7 Necrotic lung lesions in WG are radiologically much like those observed in TB. It is well worth mentioning the literature presents two case reports in which these two diseases coexisted.8 Although ANCAs are considered Sodium sulfadiazine to be markers of systemic vasculitis and are associated with WG and other autoimmune disorders, ANCA positivity has been demonstrated in infectious diseases such as TB, especially the c-ANCA pattern, increasing the possibility of diagnostic confusion with WG.2, 7, 9, 10 can stimulate the release of oxygen metabolites from activated neutrophils, which would launch lysosomal enzymes in the early stages of illness, with the potential to induce autoantibodies against these parts.7 In this case, the patient met diagnostic criteria for WG, and experienced high levels of c-ANCA, generating diagnostic doubt about the possibility of concomitant diseases. The absence of earlier sinusopathy, asymmetry of pulmonary involvement, and lack of involvement of medium size vessels (livedo, ulcers, or Sodium sulfadiazine necrosis of extremities), Sodium sulfadiazine indicated an atypical form of TB. The patient was submitted to an antituberculous routine (RIPE) and corticosteroid therapy 1?mg/kg/day time, with remission of the condition after one month of treatment, and normalization of c-ANCA after six months. In countries with a high prevalence of TB, the presence of autoantibodies in a patient with vasculitis, fever, and pulmonary cavitation requires the investigation of infectious causes, especially tuberculosis, before admitting the analysis of WG.2, 7 Financial support None declared. Authors contribution Luana Moraes Campos: Authorization of the Sodium sulfadiazine manuscript; drafting of the manuscript; effective participation in study orientation; effective participation in propaedeutics; literature review; critical review of the manuscript. Mariana Righetto de R: Authorization of the manuscript; drafting of the manuscript; effective participation in study orientation; effective participation in propaedeutics; literature review; critical review of the manuscript. Priscila Neri Lacerda: Authorization of the manuscript; drafting of the manuscript; effective participation in study orientation; effective participation in propaedeutics; literature review; critical review of the manuscript. Hlio Amante Miot: Authorization of the manuscript; drafting of the manuscript; effective participation in study orientation; effective participation in propaedeutics; literature review; critical review of the manuscript. Conflicts of Interest None declared. Footnotes How to cite this short article: Campos LM, de R MR, Lacerda PN, Miot HA. Case for analysis. Cutaneous small vessel vasculitis (anti-proteinase 3 positive), fever, hemoptysis, and lung cavitation in an adult. An Bras Dermatol. 2021;96:240C2. Study carried out in the Division of Dermatology and Radiotherapy, School of Medicine, Universidade Estadual Paulista, Botucatu, SP, Brazil..