Comparison of cutaneous manifestations in systemic polyarteritis nodosa and microscopic polyangiitis

Annular vasculitic lesions

Vasculitic skin findings may present with annular morphologies. This group of conditions consists of capillaritis, such as pigmented purpuric dermatoses, and vasculitis, which is often classified by the affected vessel size. Annular vasculitic lesions may be the presenting sign of systemic disease, thus requiring thorough exploration to reach an accurate diagnosis and guide proper disease management. Herein we review the clinical presentation, histopathology, and treatments for cutaneous vasculitic disease that may present with annular lesions.

An unusual form of kidney injury without glomerulonephritis in microscopic polyangiitis: a case report

BACKGROUND

Microscopic polyangiitis (MPA), a kind of antineutrophil cytoplasmic autoantibody associated vasculitis (AAV), predominantly affects small-sized vessels. MPA is a significant cause of the pulmonary-renal syndrome. Pauci-immune necrotizing and crescentic glomerulonephritis is the typical renal histological feature of AAV. Tubulointerstitial lesions may occur and mostly form with inflammatory cell infiltration in the interstitium. However, a few cases reported only tubulointerstitial involvement without glomerular lesions in patients with MPA.

CASE PRESENTATION

We present an MPA case, a 70-year-old male patient diagnosed with acute kidney injury accompanying the dialysis requirement. Only acute tubulointerstitial nephritis was revealed in kidney biopsy without evidence of glomerular injury. Also, interstitial pulmonary fibrosis was determined on computerized tomography, and myeloperoxidase antineutrophil cytoplasmic autoantibody was positive. Consequently, we have considered the main diagnosis as MPA. We did not prefer a standard tubulointerstitial nephritis treatment regimen due to the presence of life-threatening systemic vasculitis. Treatment was established like crescentic glomerulonephritis. Induction therapy consisted of pulse steroid, cyclophosphamide, and plasmapheresis. Unfortunately, severe SARS-CoV-2 infection caused death during induction therapy in this case.

CONCLUSIONS

The lack of glomerular injury and solely interstitial inflammation is atypical regarding AAV involvement in the kidney. This diversity might be initially considered as only a simple histological elaboration. However, it is a significant entity for guiding the treatment of AAV.

Differentialdiagnose Vaskulitis und Vaskulopathie aus dermatologischer Sicht

Vaskulopathien und Vaskulitiden stellen diagnostisch und therapeutisch eine interdisziplinäre Herausforderung dar. Zugrunde liegen unterschiedliche pathophysiologische Mechanismen, die zu vielfältigen klinischen Krankheitsbildern führen können und therapeutisch unterschiedliche Ansätze erlauben. Sowohl Vaskulitiden als auch Vaskulopathien müssen nicht zwangsläufig mit einer Systembeteiligung einhergehen, sondern können auch als rein kutane Varianten auftreten. Aufgrund mangelnder pathognomonischer Laborparameter ist die Diagnose häufig klinisch zu stellen. Dieser Artikel soll den differentialdiagnostischen Blick, insbesondere auf die kutanen Manifestationsformen bei Vaskulopathien und Vaskulitiden, schärfen.

Antiphospholipid-negative Sneddon's syndrome: A comprehensive overview of a rare entity

The term Sneddon's syndrome (SS) has been used since 1965 to describe a vasculopathy characterized by a combination of cerebrovascular disease with livedo racemosa. SS may be classified as antiphospholipid+ (aPL+) or antiphospholipid- (aPL-). Little is known about aPL- SS; in this review we describe the epidemiology and pathogenesis of aPL- SS, as well as the clinical and histologic features. We discuss recent findings in terms of neurologic and cardiac involvement. Moreover, differential diagnoses of conditions that may present with both livedo racemosa and stroke are discussed. Finally, we discuss real-life practical issues such as the initial investigations to be performed, long-term follow-up, and therapeutic management of aPL- SS patients.

Exploratory classification of clinical phenotypes in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis using cluster analysis

A novel patient cluster in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) may be identified in Japan. We performed multiple correspondence and cluster analysis regarding 427 clinically diagnosed AAV patients excluding eosinophilic granulomatosis with polyangiitis. Model 1 included the ANCA phenotype, items of the Birmingham Vasculitis Activity Score, and interstitial lung disease; model 2 included serum creatinine (s-Cr) and C-reactive protein (CRP) levels with model 1 components. In seven clusters determined in model 1, the ANCA-negative (n = 8) and proteinase 3-ANCA-positive (n = 41) groups emerged as two distinct clusters. The other five myeloperoxidase-ANCA-positive clusters were characterized by ear, nose, and throat (ENT) (n = 47); cutaneous (n = 36); renal (n = 256), non-renal (n = 33); and both ENT and cutaneous symptoms (n = 6). Four clusters in model 2 were characterized by myeloperoxidase-ANCA negativity (n = 42), without s-Cr elevation (< 1.3 mg/dL) (n = 157), s-Cr elevation (≥ 1.3 mg/dL) with high CRP (> 10 mg/dL) (n = 71), or s-Cr elevation (≥ 1.3 mg/dL) without high CRP (≤ 10 mg/dL) (n = 157). Overall, renal, and relapse-free survival rates were significantly different across the four clusters in model 2. ENT, cutaneous, and renal symptoms may be useful in characterization of Japanese AAV patients with myeloperoxidase-ANCA. The combination of s-Cr and CRP levels may be predictive of prognosis.

Cutaneous Manifestations of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

Cutaneous manifestations of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA), are poorly characterized. This report describes the dermatologic features of AAV and their association with systemic manifestations of vasculitis.

METHODS

A cross-sectional study identifying and comparing the cutaneous manifestations of AAV was performed using data from a large, international, collaborative effort in order to collect comprehensive clinical data on patients with vasculitis.

RESULTS

Data from 1,184 patients with AAV from 130 centers worldwide were available. Cutaneous manifestations were common in all AAV subtypes: GPA (223 of 656, or 34%), MPA (85 of 302, or 28%), and EGPA (106 of 226, or 47%). The most frequent cutaneous manifestation in AAV (all types) was petechiae/purpura, which was observed in 181 patients (15%). Allergic and nonspecific manifestations, such as pruritus, urticaria, and maculopapular rash, were more common in EGPA than in other disease subtypes (all P < 0.01). Skin biopsy, while underutilized (performed in 22-44% of patients), was frequently found to be an effective test suitable for diagnosis of AAV (diagnostic in 68-94% of patients). Compared to patients without cutaneous manifestations, those with skin lesions more frequently had severe systemic manifestations of vasculitis (such as alveolar hemorrhage and glomerulonephritis), specifically patients with GPA or EGPA and cytoplasmic/anti-proteinase 3 (anti-PR3) ANCA-positive or ANCA-negative patients (hazard ratio >1.9 for all), but not those with MPA or perinuclear/antimyeloperoxidase ANCAs.

CONCLUSION

Cutaneous manifestations are common and varied in AAV and are associated with disease severity in patients with GPA, EGPA, cytoplasmic/anti-PR3 ANCA, or ANCA-negative disease. These findings underscore the potential diagnostic and prognostic importance of the cutaneous examination in the evaluation and management of AAV.

Сutaneous Vasculitis: Classification, Diagnosis and Differential Diagnosis (Part 2)

This article is a continuation of the literature review on skin vasculitis. In the first part, information was presented on the current nomenclature and prevalence of vasculitis, pathomorphological changes in the skin, as well as diagnostic algorithms for examining patients with this pathology are reflected. The second part of the article contains a detailed description of the elements of the skin rash with systemic and organ-specific vasculitis, presents the clinical manifestations observed with damage to other organs and systems, the development of possible complications. The data on modern treatment tactics are summarized, modern approaches using pathogenetic and symptomatic therapy of patients with various vasculitis are reflected.

Management of cutaneous vasculitis

Cutaneous vasculitis encompasses cutaneous components of systemic vasculitides, skin-limited variants of systemic vasculitides, such as IgA vasculitis or cutaneous polyarteritis nodosa, and single-organ cutaneous vasculitis, as individualized in 2012 in the Chapel Hill Consensus Conference Nomenclature. In this article, we focus on the management of skin-limited and single-organ vasculitides, often referred to, in clinical practice, as isolated "cutaneous leukocyctoclastic vasculitis", terms which may correspond to histological findings or descriptions, but are imprecise and not specific. Since most cases of isolated cutaneous vasculitis are self-limited and resolve spontaneously over 3 to 4 weeks, most patients require no systemic treatment. For those with severe, intractable, or chronic and recurring vasculitis, systemic therapy can be indicated and should be tailored to the severity of the disease. High-quality literature is lacking to guide management. Oral glucocorticoids may be required for a short period of time for painful, ulcerative, or otherwise severe disease in order to speed resolution. Among drugs which are reasonable longer-term options are colchicine, dapsone, azathioprine or hydroxychloroquine. Additional studies, including an ongoing multicenter randomized trial, are needed to determine the most effective therapies for skin-limited vasculitis.

Update on vasculitis: overview and relevant dermatological aspects for the clinical and histopathological diagnosis - Part II

Vasculitis is a group of several clinical conditions in which the main histopathological finding is fibrinoid necrosis in the walls of blood vessels. This article assesses the main dermatological aspects relevant to the clinical and laboratory diagnosis of small- and medium-vessel cutaneous and systemic vasculitis syndromes. The most important aspects of treatment are also discussed.

Practical approach to vasculitides in adults: an overview of clinical conditions that can mimic vasculitides closely

Primary systemic vasculitides are rare diseases affecting blood vessel walls. The type and patterns of distribution of the organs affected usually reflect the size of the vessels predominantly involved, and the patterns of clinical manifestations are generally useful to reach a specific diagnosis. However, presenting symptoms may lack adequate specificity for a prompt diagnosis, leading to a diagnostic (and therapeutic) delay, often causing irreversible damage to the affected organs. Due to their rarity and variable clinical presentation, the diagnosis of primary vasculitides could be challenging for physicians. Vasculitis mimickers, i.e. the clinical conditions that could be likely mistaken for vasculitides, need to be carefully ruled out, especially before starting the immunosuppressive therapy. We present here a practical approach to the diagnosis of primary systemic vasculitides involving large, medium and small size vessels, and reviewed most of the conditions that could mimic primary systemic vasculitides.

The color of skin: purple diseases of the skin, nails, and mucosa

The color purple can be seen in several types of eruptions including inflammatory dermatoses like lichen planus, infectious dermatoses like ecthyma gangrenosum, neoplasms like Kaposi sarcoma, and vasculitis and vasculopathy. The current review focuses on the clinical appearance, pathophysiology, and treatment of several vasculitides and vasculopathies including capillaritis, cutaneous small-vessel vasculitis, immunoglobulin A (IgA) vasculitis, cryoglobulinemia, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis, polyarteritis nodosum, warfarin-induced skin necrosis, heparin-induced thrombocytopenia, purpura fulminans, antiphospholipid antibody syndrome, calciphylaxis, levamisole-induced vasculopathy, and thrombotic thrombocytopenic purpura. Dermatologists play a central role in treating patients with cutaneous vasculitis and vasculopathy and may have the opportunity to facilitate identification of systemic disease by diagnosing cutaneous vasculitis and vasculopathy.

[Cutaneous alterations in vasculitides : Part 2: Special aspects of diseases of large, medium and small vessels]

Cutaneous vasculitides present with typical clinical signs depending on the size and distribution of the affected vessels. Since there are no large vessels in the skin, giant cell arteritis and Takayasu's arteritis only rarely lead to cutaneous symptoms. The classical systemic polyarteritis nodosa (PAN) is very rare. More frequent is cutaneous PAN presenting with a typical localized livedo racemosa and palpable subcutaneous nodules. The ANCA-associated vasculitides, which belong to the small vessel vasculitides, usually show systemic involvement and manifest on the skin with a diverse picture. Immune complex vasculitides are characterized by deposition of immunoglobulins on the walls of small vessels. The most common form is IgA vasculitis with the cardinal symptoms of palpable, round or oval and partially branched (retiform) purpura and a clear predilection for the legs. Serum disease is a príme example of systemic immune complex diseases due to large circulating immune complexes. Cryoglobulinemic vasculitis primarily involves small as well as medium sized vessels. Simultaneous involvement of vessels of different sizes is characteristic for vasculitis in systemic lupus erythematosus (SLE), Sjögren's syndrome, rheumatoid arthritis and sarcoidosis. Recurrent macular vasculitis in hypergammaglobulinemia is an episodic macular vasculitis of the small blood vessels. Bacteremic vasculitis of the small vessels (without direct microbial infection of the vessel wall) can typically also affect capillaries of dermal papillae and is usually accompanied by a disseminated intravascular coagulation (DIC). In some cases more than one distinct cutaneous vasculitis can occur in the same patient.

Cutaneous Polyarteritis Nodosa Presenting Atypically with Severe Pharyngeal Ulceration

Polyarteritis nodosa (PAN) is a multisystem, necrotising vasculitis of small- and medium-sized arteries with a predilection for the visceral vessels. Cutaneous PAN is a rare variant with symptomatic vasculitis limited to the skin, typically presenting as nodular lesions on the extremities with a propensity to ulcerate. We describe a rare case of histologically confirmed cutaneous PAN presenting in a 55-year-old Ghanaian woman with severe oropharyngeal ulceration. This was associated with dysphagia and significant weight loss. Oesophagoduodenoscopy showed that the ulceration extended throughout the oropharynx. Systemic polyarteritis nodosa was ruled out with magnetic resonance angiography. Our patient was treated successfully with corticosteroids and methotrexate. This case suggests that cutaneous PAN should be considered in the differential diagnosis of patients with oropharyngeal ulceration and that histological assessment is pivotal in establishing the diagnosis early in order to instigate appropriate therapy.

Cutaneous Manifestations of ANCA-Associated Small Vessels Vasculitis

Skin lesions are frequent manifestations of underlying systemic conditions, including systemic autoimmune vasculitis. In particular, anti-neutrophil cytoplasmic antibodies (ANCA) are associated with distinct forms of vasculitis characterized by inflammatory cell infiltration of the walls of small and medium-sized vessels leading to vascular destruction and tissue necrosis. ANCA-associated vasculitis is rare and systemic diseases, which can be classified based on different distribution of vascular inflammation and presence or absence of granulomatosis and asthma. Despite their diversities, ANCA-associated vasculitis, namely microscopic polyangiitis, granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis, can all display a broad variety of cutaneous manifestations, which can appear during the course of the disease or even as first sign at the time of onset. Different skin manifestations might coexist in the same patient and occur in different occasions during the course of the vasculitis. Thus, a deep knowledge of the spectrum of skin lesions as part of ANCA-associated vasculitis is mandatory for a correct diagnostic process, whenever cutaneous vasculitis is suspected. Due to this broad variety of manifestations, the diagnosis of skin involvement in ANCA-associated vasculitis is very challenging and it must be supported by a detailed medical history, accurate physical examination, specific histopathological analysis of skin biopsy and the presence of ANCA serology. In this review, we focus on the cutaneous manifestations that can develop in the context of ANCA-associated vasculitis, detailing the clinical features, the histopathological aspects as well as the direct immunofluorescence studies for each of the three conditions. Moreover, we acknowledged the differential diagnoses that must be ruled out in the diagnostic process and the main therapeutic approaches available for treatment of ANCA-associated vasculitis.

Histopathology of Cutaneous Inflammatory Disorders in Children

Inflammatory dermatoses encompass a variety of histologic patterns that affect different portions of the skin. In spongiotic, psoriasiform, lichenoid, pityriasiform, and blistering disorders, there are predominately epidermal and junctional activities with variable superficial dermal inflammation. Hypersensitivity reactions can show either epidermal or mostly dermal changes depending on whether the exposure of the exogenous allergen occurs through an external or internal route, respectively. Exceptions include erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis, where the etiology is often due to infection or ingested medications, but the histologic features are almost exclusively confined to the epidermis and dermoepidermal junction. Autoimmune disorders are unique in that lesions typically incorporate a mixture of epidermal and dermal inflammatory patterns with periadnexal inflammation, while the vast majority of vasculitis/vasculopathy and alopecia have changes limited to only the vessels and hair follicles, respectively. It is critical to recognize that a relatively limited number of histologic patterns are seen in a large array of clinical entities. Therefore, clinicopathologic correlation and careful examination of histologic details are of the utmost importance when evaluating skin biopsies for inflammatory disorders.

Nomenclature of Cutaneous Vasculitis: Dermatologic Addendum to the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides

OBJECTIVE

To prepare a dermatologic addendum to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides (CHCC2012) to address vasculitides affecting the skin (D-CHCC). The goal was to standardize the names and definitions for cutaneous vasculitis.

METHODS

A nominal group technique with a facilitator was used to reach consensus on the D-CHCC nomenclature, using multiple face-to-face meetings, e-mail discussions, and teleconferences.

RESULTS

Standardized names, definitions, and descriptions were adopted for cutaneous components of systemic vasculitides (e.g., cutaneous IgA vasculitis as a component of systemic IgA vasculitis), skin-limited variants of systemic vasculitides (e.g., skin-limited IgA vasculitis, drug-induced skin-limited antineutrophil cytoplasmic antibody-associated vasculitis), and cutaneous single-organ vasculitides that have no systemic counterparts (e.g., nodular vasculitis). Cutaneous vasculitides that were not included in the CHCC2012 nomenclature were introduced.

CONCLUSION

Standardized names and definitions are a prerequisite for developing validated classification and diagnostic criteria for cutaneous vasculitis. Accurate identification of specifically defined variants of systemic and skin-limited vasculitides requires knowledgeable integration of data from clinical, laboratory, and pathologic studies. This proposed nomenclature of vasculitides affecting the skin, the D-CHCC, provides a standard framework both for clinicians and for investigators.

Autoimmune comorbidity in chronic spontaneous urticaria: A systematic review

BACKGROUND AND OBJECTIVE

Numerous autoimmune diseases (AIDs) have been linked to chronic spontaneous urticaria (CSU). Here, we provide the first extensive and comprehensive evaluation of the prevalence of AIDs in patients with CSU and vice versa.

METHODS

A Pubmed and Google Scholar search was performed to identify studies reporting the prevalence of various AIDs in CSU and vice versa published before April 2017.

RESULTS

The prevalence of individual AIDs in CSU is increased (≥1% in most studies vs ≤1% in the general population). AIDs with relatively high prevalence in the general population are also quite common in CSU patients, whereas those with low prevalence remain a rare finding in CSU. The rates of comorbidity in most studies were ≥1% for insulin-dependent diabetes mellitus, rheumatoid arthritis (RA), psoriasis and celiac disease (CD), ≥2% for Graves' disease, ≥3% for vitiligo, and ≥5% for pernicious anemia and Hashimoto's thyroiditis. Organ-specific AIDs are more prevalent in CSU than systemic (multiorgan or non organ-specific) AIDs. >2% of CSU patients have autoimmune polyglandular syndromes encompassing autoimmune thyroid disease (ATD) and vitiligo or pernicious anemia. Antithyroid and antinuclear antibodies are the most prevalent AID-associated autoantibodies in CSU. >15% of CSU patients have a positive family history for AIDs. The prevalence of urticarial rash in AID patients is >1% in most studies. This rash is more prevalent in eosinophilic granulomatosis with polyangiitis, ATD, systemic lupus erythematosus, RA and CD.

CONCLUSIONS

CSU patients have an increased risk of AIDs, especially adult female patients and those with a positive family history and a genetic predisposition for AIDs, who should be screened for signs and symptoms of AIDs.

[Cutaneous symptoms of various vasculitides]

The skin is one of the organs most frequently involved in vasculitides. Cutaneous vasculitis may present (1) part of a systemic vasculitis (e.g., IgA vasculitis), (2) a skin-restricted or skin-dominant variant of the corresponding systemic vasculitis without clinically apparent visceral involvement (e.g., cutaneous IgA vasculitis), or (3) a vasculitis occurring exclusively in the skin (e.g., erythema elevatun diutinum). The clinical symptoms of vasculitides are markedly determined by the size of the predominantly affected blood vessels. Systemic polyarteritis nodosa is regarded as a medium vessel vasculitis and is associated with multiple skin symptoms: (1) vasculitis of digital arteries with ensuing digital infarction, (2) livedo racemosa and subcutaneous nodules, and (3) in some patients even purpura and hemorrhagic macules due to additional small vessel vasculitis. In contrast, in its skin-restricted entity (i.e., cutaneous polyarteritis nodosa), the predominant symptoms are subcutaneous nodules surrounded by livedo racemosa, often on the lower legs. Among small-vessel vasculitides palpable purpura with predilection for the legs is a nearly pathognomonic feature of immune complex vasculitis. Variations in clinical symptoms indicate additional pathophysiological mechanisms or different vascultides: (1) ANCA-associated vasculitides often also entail nodules or sometimes livedo, (2) cryoglobulinemic vasculitis additionally may present with necrosis at cold exposed areas and involvement of vessels of various size, (3) small vessel vasculitis associated with systemic lupus erythematosus or rheumatoid arthritis shows predilection for additional sites (e.g., nailfolds) and also involvement of vessels beyond postcapillary venules, (4) recurrent macular vasculitis in hypergammaglobulinemia also occurs on dependent parts, but shows numerous small hemorrhagic macules instead of palpable purpura, (5) erythema elevatum diutinum begins with brightly red to violaceous plaques at extensor sites, followed by fibrotic nodules. Consequently, cutaneous symptoms provide pivotal clues for further diagnosis and ensuing management of vasculitides.

Microscopic polyangiitis: Advances in diagnostic and therapeutic approaches

Microscopic polyangiitis (MPA) is an idiopathic autoimmune disease characterized by systemic vasculitis. The disease predominantly affects small-calibre blood vessels and is associated with the presence of antineutrophil cytoplasmic autoantibodies (ANCA). Microscopic polyangiitis was considered to be a disease entity by Savage et al. in 1985. Microscopic polyangiitis has a reported low incidence and a slight male predominance. The aetiology of MPA remains unknown. There is, however, increased evidence that MPA is an autoimmune disease in which ANCAs, particularly those reacting with MPO, are pathogenic. MPA belongs to the systemic vasculitides, indicating that multiple organs can be affected. The major organs involved in MPA are the kidneys and the lungs. As expected for an illness that affects multiple organ systems, patients with MPA can present with a myriad of different symptoms. Ear, nose and throat (ENT) manifestations are not considered to be clinical symptoms of MPA, but in the majority of populations described, ENT involvement was found in surprisingly high percentages. MPA is part of the ANCA-associated vasculitides, which are characterized by necrotizing vasculitis of small vessels. Diagnosis is mainly established by clinical manifestations, computed tomography (TC), ANCA antibody detection and renal and pulmonary biopsy. The introduction of aggressive immunosuppressive treatment has substantially improved the prognosis. The standardized therapeutic regimen is based on cyclophosphamide and corticosteroids. Using this regimen, remission can be achieved in most of the patients. Rituximab may represent an important alternative to cyclophosphamide for patients who may not respond adequately to antimetabolite therapies.

Nonarteriosclerotic vascular disease

Thromboangiitis obliterans, or Buerger disease, is a chronic nonatherosclerotic endarteritis manifesting as inflammation and thrombosis of distal extremity small and medium-sized arteries resulting in relapsing episodes of distal extremity ischemia. Takayasu arteritis is a rare syndrome characterized by inflammation of the aortic arch, pulmonary, coronary, and cerebral vessels, presenting with cerebrovascular symptoms, myocardial ischemia, or upper extremity claudication in young, often female, patients. Kawasaki disease is a small- and medium-vessel acute systemic vasculitis of young children, with morbidity and mortality stemming from coronary artery aneurysms. Microscopic polyangiitis, Churg-Strauss syndrome, and Wegener granulomatosis are systemic small-vessel vasculitides, affecting arterioles, capillary beds and venules, and each presenting with variable effects on the pulmonary, renal and gastrointestinal systems.

[Skin manifestations of different forms of vasculitis]

The skin not only represents the organ which often reveals the first signs of systemic vasculitis, but also the organ which is most frequently involved in vasculitis. These diseases encompass systemic vasculitides and those which appear to involve the skin only. Among those vasculitides restricted to the skin, some are yet typically associated with other systemic diseases, such as nodular vasculitis, which often occurs during infections by M. tuberculosis, or erythema elevatum diutinum in patients with gammopathy. The type and localization of skin lesions give valuable indications as to the type of vasculitis. Subcutaneous nodules which ulcerate and are surrounded by livedo racemosa are suggestive of polyarteritis nodosa, a palpable purpura with predilection for the lower legs is almost pathognomonic for immune complex vasculitis (e.g. IgA vasculitis or cutaneous leukocytoclastic vasculitis), hemorrhagic papules and necrotic plaques which occur in acral areas after cooling indicate cryoglobulinemic vasculitis, hemorrhagic papules and macules which develop in patients who start to feel worse and develop fever should arouse suspicion of septic vasulitis, while the simultaneous presence of ulcerating nodules and hemorrhagic papules without predilection for the lower legs will suggest ANCA-associated vasculitis. The different morphology of the cutaneous signs of the various vasculitides depends to a large extent on the size of the vessels primarily involved. In this review the cutaneous signs of vasculitides will be presented with reference to the revised nomenclature of the Chapel Hill Consensus Conference from 2012.

Coexistence of polyarteritis nodosa and psoriatic arthritis in a child: an unreported association: Polyarteritis nodosa and Psoriatic arthitritis

Polyarteritis nodosa (PAN) is a non-frequent vasculitis of small- and medium-sized vessels. Psoriatic arthritis (PA) is described as a "unique inflammatory arthritis associated with psoriasis" with an inexact prevalence rate due to the lack of widely accepted classification criteria. We describe the case of an 11-year-old boy that presented with fever of unknown origin plus clinical signs of sacroiliitis, bilateral enthesitis of the plantar fascia, and skin psoriasis. He acutely developed erythematous and tender nodular lesions in the lower limbs that lasted around 3 weeks and spontaneously disappeared at the same time as the fever. He was diagnosed as having PAN and PA according to clinical and histological criteria. This is the first report of the coexistence of PAN and PA in a child indicating a possible relation (maybe cross-reactivity of an infectious agent) between PAN and spondiloarthritis.

Diagnostic approach to ANCA-associated vasculitides

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) include Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. Given their rarity, protean clinical manifestations, imperfect diagnostic tests, and wide differential diagnosis, they pose a diagnostic challenge even to experienced clinicians. This article describes diagnostic approaches for patients suspected of having one of the ANCA-associated vasculitides. The clinical findings at presentation, the role of laboratory and imaging tests, and the importance of tissue diagnosis are presented. In each section, issues relevant to the differential diagnosis of AAV are discussed.

Microscopic polyangiitis: Clinical presentation

Microscopic polyangiitis (MPA) is a member of the family of ANCA-associated vasculitides. Its characteristic histology shows a necrotizing small vessel vasculitis with little or absent immune deposits (pauci-immune vasculitis). In Western countries MPA shows a lower prevalence than Wegener's disease, it affects more men than women and commences at the age of > or = 50 years. The two organs most typically involved and often defining prognosis are the kidneys and the lungs. MPA may concomitantly or sequentially involve other organs such as the nervous system, the skin, the musculoskeletal system, but also the heart, the eye and the intestines. Treatment decisions should be based on severity and pattern of organ involvement and respect the five factor score (FFS). Life- or organ- threatening disease is treated with glucocorticoids and (pulse) cyclophosphamide. Plasmapheresis and i.v.immunoglobulins have been shown to be beneficial as additional measure in severe cases. If renal function is preserved, Methotrexate may be considered to induce remission, and if the FFS equals 0, remission may be induced with glucocorticoid monotherapy. Maintenance therapy is recommended with Azathioprin, mycophenolate mofetil may be used as a second line drug. Biologic agents such as monoclonal antibodies to tumor necrosis factor a and B cell depleting rituximab have been shown to bear remission-inducing quality.

Microscopic polyangiitis

In 1923, Friedrich Wohlwill described two patients with a "microscopic form of periarteritis nodosa," which was distinct from the classical form. This disease, now known as microscopic polyangiitis (MPA), is a primary systemic vasculitis characterized by inflammation of the small-caliber blood vessels and the presence of circulating antineutrophil cytoplasmic antibodies. Typically, microscopic polyangiitis presents with glomerulonephritis and pulmonary capillaritis, although involvement of the skin, nerves, and gastrointestinal tract is not uncommon. Treatment of MPA generally requires use of a cytotoxic agent (such as cyclophosphamide) in addition to high-dose glucocorticoids. Recent research has focused on identifying alternate treatment strategies that minimize or eliminate exposure to cytotoxic agents. This article reviews the history, pathogenesis, clinical manifestations, and treatment of MPA.

Urticarial lesions: if not urticaria, what else? The differential diagnosis of urticaria: part II. Systemic diseases

There are a number of systemic disorders that can manifest with urticarial skin lesions, including urticarial vasculitis, connective tissue diseases, hematologic diseases, and autoinflammatory syndromes. All of these conditions may enter into the differential diagnosis of ordinary urticaria. In contrast to urticaria, urticarial syndromes may manifest with skin lesions other than wheals, such as papules, necrosis, vesicles, and hemorrhages. Lesions may have a bilateral and symmetrical distribution; individual lesions have a long duration, and their resolution frequently leaves marks, such as hyperpigmentation or bruising. Moreover, systemic symptoms, such as fever, asthenia, and arthralgia, may be present. The most important differential diagnosis in this group is urticarial vasculitis, which is a small-vessel vasculitis with predominant cutaneous involvement. Systemic involvement in urticarial vasculitis affects multiple organs (mainly joints, the lungs, and the kidneys) and is more frequent and more severe in patients with hypocomplementemia. Clinicopathologic correlation is essential to establishing a correct diagnosis.

LEARNING OBJECTIVES

After completing the learning activity, participants should be able to distinguish urticarial lesions suggesting diagnoses other than common urticaria; assess patients with urticarial lesions, and suspect systemic diseases presenting with urticarial skin lesions.