Lea Salamon

Background and Clinical Significance: Cocaine-induced vasculitis (CIV), especially when associated with PR3-ANCA positivity, can be very similar both clinically and serologically to idiopathic granulomatosis with polyangiitis (GPA). The distinction between these entities is crucial due to the different etiologies, treatment strategies, and prognoses. We present a unique case of CIV that manifested exclusively in a previously dissected neck area—an example of the locus minoris resistance phenomenon—and was initially misinterpreted as skin melanoma recurrence. Case presentation: A 59-year-old man with a history of skin melanoma (pT4b, left pectoral region) and a previous modified radical neck dissection presented in 2024 with new onset of painful subcutaneous nodules and ulcerative lesions at the surgical site. The imaging procedures (CT and PET-CT) raised the suspicion of locoregional malignant recurrence. However, histology revealed necrotizing granulomatous inflammation without tumor cells. Extensive infectious and autoimmune investigations ruled out alternative causes. Subsequently, the patient developed a perforation of the nasal septum and ulcers on the oral mucosa. PR3-ANCA was strongly positive (up to 49 U/mL). Urine toxicology revealed intranasal cocaine use. A diagnosis of cocaine-induced PR3-ANCA vasculitis was made. After immunosuppressive therapy (high-dose glucocorticoids and methotrexate) and substance withdrawal counseling, the patient showed significant clinical improvement. Conclusions: This case highlights the importance of including CIV in the differential diagnosis of granulomatous or ulcerative lesions, especially when they are localized to previous surgical sites. The presentation illustrates the concept of locus minoris resistentiae and highlights the role of toxicological testing in atypical ANCA-positive disease.

The purpose of the study was to examine whether rheumatoid arthritis (RA) patients have higher prevalence of metabolic syndrome (MetS) than osteoarthritis (OA) patients in association with a higher level of chronic systemic inflammation in rheumatoid arthritis. A total of 583 RA and 344 OA outpatients were analyzed in this multicentric study. Metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria. A 1.6-fold higher prevalence of MetS was found in patients with OA compared with the RA patients. Among the parameters of MetS, patients with OA had significantly higher levels of waist circumference, systolic blood pressure, fasting blood glucose and triglycerides, whereas HDL cholesterol and diastolic blood pressure values were similar in both groups of patients. Higher values of inflammatory markers [C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)] in MetS than in non-MetS patients and higher prevalence of MetS in patients with CRP level ≥5 mg/L in both RA and OA patients were found. In multivariate logistic regression analysis, significant predictors of MetS were type of arthritis (OA vs. RA; OR 2.5 [95 % CI 1.82–3.43]), age (OR 1.04 [95 % CI 1.03–1.06]) and ESR (OR 1.01; [95 % CI 1.00–1.01]). The significant association between OA and MetS was maintained in the regression model that controlled for body mass index (OR 1.87 [95 % CI 1.34–2.61]). The present analysis suggests that OA is associated with an increased risk of MetS, which may be due to a common underlying pathogenic mechanism.

Hereditary angioedema is a rare genetic disorder resulting from an inherited deficiency or dysfunction of the C1 inhibitor. It is characterized by recurrent, circumscribed, and self-limiting episodes of cutaneous and mucous membrane swelling involving different organs. Hereditary angioedema may present with diverse clinical pictures, even within families with the same mutation. We present a first reported case of type 1 hereditary angioedema in a young woman presenting as recurrent abdominal pain associated with ascites without any other clinical features of hereditary angioedema, with initial presentation in puerperium. The recognition or awareness of hereditary angioedema as a cause of acute and/or recurrent abdominal pain associated with ascites is important, and may avoid unnecessary invasive procedures and facilitate appropriate treatment.

Systemic lupus erythematosus, an autoimmune disorder which predominantly affects young women, is frequently complicated by renal involvement. Lupus nephritis (LN) is characterized by immune-complex mediated glomerular and tubulointerstitial inflammation Ieading to chronic renal insufficiency in up to 30% affected patients. In patients with suspected lupus nephritis, renal biopsy may be used to confirm the diagnosis and determine appropriate therapy. The ISN/RPS classification of LN represents a significant advance over the 1982 WHO scheme. The treatment of lupus nephritis often consists of a period of intensive immunosuppressive therapy (induction therapy) followed by a period of less intensive maintenance therapy. The established treatment of lupus nephritis with cyclophosphamide and steroids has improved the outcome of LN but is burdened with significant adverse effects. Results of clinical studies showed that mycophenolate mofetil is equally effective with fewer toxic complications than standard therapy, but its long-term efficacy is not yet known. New therapeutic agents (biologic drugs) targeted to the pathogenetic mechanism of the disease are promissing improved efficacy with less toxicity. Despite recent advances, treatment of lupus nephritis remains a challenging clinical problem.