Lymphocytic thrombophilic arteritis and cutaneous polyarteritis nodosa: Clinicopathologic comparison with blinded histologic assessment

Occlusive cutaneous vasculopathies as cause of chronic ulcers

The term occluding vasculopathies covers a large number of different conditions. These often manifest as skin ulcers. Occluding vasculopathies should be considered in the differential diagnosis of leg ulcers. The term "occlusive vasculopathies" encompasses pathophysiologically related entities that share structural or thrombotic obliteration of small cutaneous vessels. In this article, we will focus on livedoid vasculopathy with and without antiphospholipid syndrome and calciphylaxis with differentiation from hypertonic leg ulcer as the most relevant differential diagnoses of leg ulcer. The term also includes vascular occlusion, for example due to oxalate or cholesterol embolism, and septic vasculopathy. This often leads to acral ulceration and is therefore not a differential diagnosis with classic leg ulcers. It will not be discussed in this article. Occlusive vasculopathy may be suspected in the presence of the typical livedo racemosa or (non-inflammatory) retiform purpura as a sign of reduced cutaneous perfusion in the wound area. Inflammatory dermatoses, especially vasculitides, must be differentiated. This is achieved by histopathological evaluation of a tissue sample of sufficient size and depth taken at the appropriate time. In addition, specific laboratory parameters, particularly coagulation parameters, can support the diagnosis.

Okkludierende kutane Vaskulopathien als Ursachen chronischer Unterschenkelulzerationen

Unter den Begriff der okkludierenden Vaskulopathien fällt eine Reihe unterschiedlicher Krankheitsbilder. Diese manifestieren sich an der Haut häufig mit Ulzerationen. Gerade bei Ulzerationen der Unterschenkel sollten okkludierende Vaskulopathien in die differenzialdiagnostischen Überlegungen einbezogen werden. Der Begriff „okkludierende Vaskulopathien“ umfasst pathophysiologisch verwandte Entitäten, die eine strukturelle oder thrombotische Obliteration von kleinsten Hautgefäßen gemein haben. In diesem Artikel wird vor allem auf die Livedovaskulopathie mit und ohne Antiphospholipidsyndrom sowie die Calciphylaxie mit Abgrenzung zum Ulcus cruris hypertonicum als die relevantesten Differenzialdiagnosen von Unterschenkelulzerationen eingegangen. Der Begriff umfasst auch Gefäßverschlüsse, beispielsweise durch Oxalat oder Cholesterinembolie, sowie die septische Vaskulopathie. Diese führt häufig zu akralen Ulzerationen und stellt somit keine Differenzialdiagnose zum klassischen Ulcus cruris dar. Sie wird daher in diesem Artikel nicht behandelt.

Der Verdacht einer okkludierenden Vaskulopathie kann über die typische Livedo racemosa beziehungsweise die (nichtinflammatorische) retiforme Purpura als Zeichen der kutanen Minderdurchblutung in der Wundumgebung gestellt werden. Entzündliche Dermatosen, insbesondere Vaskulitiden, müssen differenzialdiagnostisch abgegrenzt werden. Dies geschieht zum Teil klinisch und durch die histopathologische Beurteilung einer Gewebeprobe, die in ausreichender Größe und Tiefe sowie zum richtigen Zeitpunkt entnommen werden muss. Ergänzend können spezifische Laborparameter, insbesondere die Gerinnungsdiagnostik, die Diagnosestellung unterstützen.

Lymphocytic vasculitis in livedoid vasculopathy: A report of 137 cases

BACKGROUND

Livedoid vasculopathy (LV) is characterized by fibrin deposition and thrombosis in the small vessels of the superficial dermis. It is widely recognized as an occlusive disease, which is primarily treated with anticoagulation therapy.

METHODS

We retrospectively analyzed the clinical and histopathological characteristics of patients diagnosed with LV at a tertiary dermatology department to explore the characteristics of lymphocytic vasculitis in LV. The frequency of vasculitis and the types of vessels involved were examined based on the diameters and elastic fiber distribution of the involved vessels. In addition, the immunophenotypes of infiltrating lymphocytes were analyzed.

RESULTS

In a large retrospective series including 358 LV cases, we identified 137 (38.3%) cases of lymphocytic vasculitis. Among them, 48 cases involved medium-sized vessels, including arterioles and venules, whereas 89 cases involved only small vessels. In addition, 12 cases displayed a segmental distribution of vasculitis. The infiltrating lymphocytes were mainly T cells, with dominant cells stained positive for CD4.

CONCLUSIONS

Lymphocytic vasculitis forms part of the histological spectrum of LV, affecting both medium-sized and small vessels. It is possible that the occlusion of small vessels may represent a phenomenon secondary to lymphocytic vasculitis.

The simultaneous occurrence of livedoid vasculopathy and lymphocytic thrombophilic arteritis in six cases

Lymphocytic thrombophilic arteritis and livedoid vasculopathy may both present with livedo racemosa and ulceration. We present 6 cases with features of both conditions, raising the possibility that they are either closely linked or are part of a spectrum of the same condition.

Cutaneous vasculitis and vasculopathy in the era of COVID-19 pandemic

Cutaneous vasculitides encompass a heterogeneous group of clinicopathological entities, which may occur as single-organ vasculitis of the skin or present as skin-limited variant of systemic vasculitis (i.e., skin-limited ANCA-associated vasculitis), and are triggered by various factors, including infections, drugs and vaccines. The COVID-19 pandemic has challenged us with a variety of both disease- and vaccine-associated skin manifestations, including vasculitis. Among the latter, cutaneous small-vessel vasculitis, previously known as leukocytoclastic vasculitis, seems to be the most reported in either scenario, i.e., natural infection and vaccination. Vasculopathy without true vasculitic changes on histology develops in but a minority of cases, mostly severe/critical COVID-19 patients, and appears to be the result of endothelial injury due to pauci-immune thromboembolic mechanisms. Herein, we provide an overview of the available literature on COVID-19-associated and anti-SARS-CoV-2-vaccine-associated cutaneous vasculitis. Although evidence is mostly limited to isolated reports, with a proportion of cases lacking histopathological confirmation, ample overlap with pre-pandemic forms is shown.

Atypical pediatric presentation of lymphocytic thrombophilic arteritis: Diagnostic difficulties and recent nosological clarification

A 4-year-old girl presented with a 2-month history of round, hypopigmented, slightly scaly patches measuring 1-6 cm and encircled by an erythematous halo, first appearing on the lower limbs then spreading to the whole body. Three biopsies were taken as the condition progressed, each showing a lymphocytic infiltrate affecting a medium-sized artery at the dermal-subcutaneous junction, with a concentric fibrin ring. These findings are characteristic of lymphocytic thrombophilic arteritis (LTA). The young age of our patient and the type of skin lesions she developed make this an atypical presentation of LTA, which usually manifests as hyperpigmented macules on the lower extremities, predominantly in dark-skinned women.

Three cases of Sneddon syndrome: A comparison with lymphocytic thrombophilic arteritis

Lymphocytic thrombophilic arteritis and Sneddon syndrome can have very similar clinical presentations with chronic persistent widespread blanchable livedo racemosa. Lymphocytic thrombophilic arteritis has only recently been described and generally is associated with a benign prognosis. Sneddon syndrome is associated with the development of multiple cerebrovascular accidents and progressive neurological impairment. We present three cases of Sneddon syndrome and compare them with lymphocytic thrombophilic arteritis to identify patients at risk of neurological events.

[Cutaneous vasculitis and vasculopathy : Differential diagnosis in biopsies of the lower extremities]

The skin is one of the most frequently involved organs in primary systemic and secondary vasculitis; moreover, a vasculitis can occur as single organ vasculitis, limited to the skin. For most types of vasculitis, the lower extremities constitute common sites with clinical symptoms of palpable purpura, nodules, and ulcers. In histopathology of cutaneous vasculitis, it is of utmost importance to correctly identify the vessel types involved and to discriminate between vasculitic vessel damage, unspecific reactive vessel changes, vascular occlusive diseases, noninflammatory purpura, or perivascular infiltrates due to other inflammatory skin diseases. Small-vessel vasculitis is the most frequent type of cutaneous vasculitis; during florid phases, a dermal leukocytoclastic vasculitis is found regardless of etiology. Additional extravascular changes may give etiological clues, however, a correlation with the clinical picture, radiology, and serology is essential. The biopsy type and technique need to be adjusted to the suspected diagnosis and site of the vessels involved. Polyarteritis nodosa and nodular vasculitis can be diagnosed only in biopsies with sufficient subcutaneous tissue. Especially in cutaneous ulcers, a lateral rim of vital skin and subcutaneous tissue is indispensable for a correct diagnosis. Large-vessel vasculitis is not found in skin biopsies of the lower extremities.