Nodular Vasculitis: Retrospective Study of an Uncommon Disease in a Non-Tuberculosis Endemic Country with Focus on Treatment Modalities and Efficacy.

Introduction: Nodular vasculitis (NV) is a rare form of panniculitis primarily affecting middle-aged females, presenting as painful, sometimes ulcerated nodules on the dorsal lower legs. Erythema induratum of Bazin (EIB) is a form of NV and is considered a manifestation of cutaneous tuberculin hypersensitivity. This retrospective study aims to analyze demographics, clinicopathological findings, laboratory results, and treatment outcomes of NV in a non-TB endemic country.

Methods: Data of NV patients were extracted from the electronic hospital database of the University Hospital Zurich. Patients were included only if histopathologically confirmed diagnosis of NV and sufficient information on demographics, treatment, and follow-up were available.

Results: We conducted a 20-year retrospective study, including 62 patients with NV. The most common site of involvement was the lower extremities. Disease duration varied from several months to over 20 years. Histopathological examination revealed lobular panniculitis, with or without vasculitis, and granuloma formation. Tuberculosis association was assessed through the QuantiFERON test and mycobacteria PCR, showing positive results in 22 or 37 (59%) tested cases and in 2 out of 27 cases (7.4%), respectively. Comorbidities were found in over half of the patients. Treatment modalities included topical corticosteroids, antitubercular therapy, systemic steroids, and potassium iodide. Almost 50% of all patients experienced relapses despite treatment.

Conclusion: Topical steroids, antitubercular therapy, systemic steroids, and potassium iodide showed similar response rates. Tuberculostatic therapy upon detecting latent TB is recommended. Considering the high recurrence rate and potential side effects of systemic therapies, we recommend first-line treatment with potent topical steroids and compression stockings.