Vascular Fibrinoid in Cutaneous “Allergic” Arteriolitis

Ceftriaxone-induced leukocytoclastic vasculitis: a case report and literature review of antibiotic-induced leukocytoclastic vasculitis

Leukocytoclastic vasculitis (hypersensitivity vasculitis) is defined as small blood vessel inflammation with skin or other systemic manifestations due to infections, drugs, or neoplastic disease. This clinical case report highlights an association between ceftriaxone and leukocytoclastic vasculitis in a 49-year-old female patient with a history of penicillin allergy, on mirtazapine for anxiety disorder. Articles concerning antibiotic-induced leukocytoclastic vasculitis are also reviewed. The patient reported a symptom of upper respiratory tract infection and fever 5 days previously for which she received ceftriaxone for 2 days before presenting to the emergency department with a pruritic skin rash in the upper and lower extremities and swollen lips for 1 day. The rash was erythematous, maculopapular, itchy, and non-tender, with no mucus membrane involvement. Laboratory investigations revealed leukocytosis (white blood cells, 22.3 × 10⁹/L) that was mainly eosinophilic (18.4%). The patient was administered prednisolone and antihistamine after stopping ceftriaxone empirically. A skin biopsy confirmed the diagnosis of leukocytoclastic vasculitis. Significant clinical improvement was observed after treatment initiation. Upon follow-up, the skin rash was resolved entirely with no scars; however, there was skin-peeling over the lower extremities. Recognition of antibiotic-induced leukocytoclastic vasculitis is crucial as many classes of antibiotics can contribute to this condition. Continuation of the offending drug may lead to life-threatening complications.

Live fibroblast harvest reveals surface marker shift in vitro

Current methods for the isolation of fibroblasts require extended ex vivo manipulation in cell culture. As a consequence, prior studies investigating fibroblast biology may fail to adequately represent cellular phenotypes in vivo. To overcome this problem, we describe a detailed protocol for the isolation of fibroblasts from the dorsal dermis of adult mice that bypasses the need for cell culture, thereby preserving the physiological, transcriptional, and proteomic profiles of each cell. Using the described protocol we characterized the transcriptional programs and the surface expression of 176 CD markers in cultured versus uncultured fibroblasts. The differential expression patterns we observed highlight the importance of a live harvest for investigations of fibroblast biology.

Vasculite cutânea de pequenos vasos: etiologia, patogênese, classificação e critérios diagnósticos - Parte I

Vasculite é a inflamação da parede dos vasos. Pode variar em gravidade desde doença autolimitada de um único órgão até doença grave com risco de morte por falência de múltiplos órgãos. Existem várias causas, embora só se apresente por poucos padrões histológicos de inflamação vascular. Vasos de qualquer tipo e em qualquer órgão podem ser afetados, resultando em ampla variedade de sinais e sintomas. Diferentes vasculites com apresentações clínicas indistinguíveis têm evolução e tratamento muito diferentes. Essa condição representa desafio para o médico, incluindo classificação, diagnóstico, exames laboratoriais pertinentes, tratamento e seguimento adequado. Neste artigo são revistos a classificação, a etiologia, a patogênese e os critérios diagnósticos das vasculites cutâneas.

Cutaneous Vasculitis Update: Diagnostic Criteria, Classification, Epidemiology, Etiology, Pathogenesis, Evaluation and Prognosis

Vasculitis, inflammation of the vessel wall, can result in mural destruction with hemorrhage, aneurysm formation, and infarction, or intimal-medial hyperplasia and subsequent stenosis leading to tissue ischemia. The skin, in part due to its large vascular bed, exposure to cold temperatures, and frequent presence of stasis, is involved in many distinct as well as un-named vasculitic syndromes that vary from localized and self-limited to generalized and life-threatening with multi-organ disease. To exclude mimics of vasculitis, diagnosis of cutaneous vasculitis requires biopsy confirmation where its acute signs (fibrinoid necrosis), chronic signs (endarteritis obliterans), or past signs (acellular scar of healed arteritis) must be recognized and presence of extravascular findings such as patterned fibrosis or collagenolytic granulomas noted. Although vasculitis can be classified by etiology, many cases have no identifiable cause, and a single etiologic agent can elicit several distinct clinicopathologic expressions of vasculitis. Therefore, the classification of cutaneous vasculitis is best approached morphologically by determining vessel size and principal inflammatory response. These histologic patterns roughly correlate with pathogenic mechanisms that, when coupled with direct immunofluorescent examination, anti-neutrophil cytoplasmic antibody (ANCA) status, and findings from work-up for systemic disease, allow for specific diagnosis, and ultimately, more effective therapy. Herein, we review cutaneous vasculitis focusing on diagnostic criteria, classification, epidemiology, etiology, pathogenesis, and evaluation of the cutaneous vasculitis patient.

Peripheral small vessel involvement in chronic nephritides

Small cutaneous vessels, obtained by ear lobe biopsies, were studied in 14 patients with various chronic nephritides and in 10 normal controls. The capillaries in the group of patients with nephritis were found to undergo two main changes: thickening of the adventitia reticularis and perivascular cellular infiltration in an inverse ratio. This infiltration was seen to be made up of mononuclear cells and an increased number of mast cells in various stages of degranulation. Changes in the basement membrane as seen by electron microscopy are not constant. All of the above changes were absent in the controls and are similar to what has been described in previous studies in both experimental and spontaneous pathologic conditions, such as experimental hypertension, diabetes mellitus, scleroderma, rheumatoid arthritis, etc. Small vessel involvement in chronic nephritides could be part of a process of diffuse microvascular damage that includes the kidneys or it may be related to hypertension or to the biochemical changes which follow uremic and pre-uremic states.