Visualization of intradermal blood vessel structures by dual-wavelength photoacoustic microscopy and characterization of three-dimensional construction of livedo-racemosa in cutaneous polyarteritis nodosa.

BACKGROUND: Photoacoustic microscopy is expected to have clinical applications as a noninvasive and three-dimensional (3D) method of observing intradermal structures. OBJECTIVE: Investigate the applicability of a photoacoustic microscope equipped with two types of pulsed lasers that can simultaneously recognize hemoglobin and melanin. METHODS: 16 skin lesions including erythema, pigmented lesions, vitiligo and purpura, were analyzed to visualize 3D structure of melanin granule distribution and dermal blood vessels. 13 cases of livedo racemosa in cutaneous polyarteritis nodosa (cPN) were further analyzed to visualize the 3D structure of dermal blood vessels in detail. Vascular structure was also analyzed in the biopsy specimens obtained from tender indurated erythema of cPN by CD34 immunostaining. RESULTS: Hemoglobin-recognition signal clearly visualized the 3D structure of dermal blood vessels and melanin-recognition signal was consistently reduced in vitiligo. In livedo racemosa, the hemoglobin-recognition signal revealed a relatively thick and large reticular structure in the deeper layers that became denser and finer toward the upper layers. The numerical analysis revealed that the number of dermal blood vessels was 1.29-fold higher (p<0.05) in the deeper region of the lesion than that of normal skin. The CD34 immunohistochemical analysis in tender indurated erythema revealed an increased number of dermal vessels compared with normal skin in 88.9% (8/9) of the cases, suggesting that vascular network remodeling had occurred in cPN. CONCLUSION: The photoacoustic system has an advantage in noninvasively detecting dermal blood vessel structures that are difficult to recognize by two-dimensional histopathology specimen examination and is worth evaluating in various skin diseases.

Sudden unexpected death of a young adult due to subarachnoid hemorrhage associated with polyarteritis nodosa: Clinicopathological appearance and literature review.

A 28-year-old male was found dead in his bedroom. There were no anomalies in his birth and medical history, and there was no family history of sudden unexpected death (SUD). Autopsy showed subarachnoid hemorrhage (SAH) with basilar top inflammatory pseudoaneurysm rupture accompanied by fibrinoid necrosis in the aneurysm wall. Active and healed arteritides in small- to medium-sized arteries were identified in the brain, heart, and systemic connective tissue, which was consistent with polyarteritis nodosa (PAN). Furthermore, pneumatosis cystoides intestinalis was observed in the ascending colon. Hepatitis B virus infection and antineutrophil nuclear antibodies were negative. Genetic investigation using whole-exome sequencing showed no mutations among autoinflammatory-related genes, including UBA1, MEFV, and ADA2. SAH due to rupture of a pseudoaneurysm formed by PAN was considered as the cause of death in the present case. Although myocardial ischemia linked to coronary arteritis is a recognized trigger for SUD in PAN, our study showed that rupture of inflammatory pseudoaneurysm in the cerebral artery can also cause SUD in younger subjects with PAN, even if prodromal symptoms are not evident before death.

Cutaneous arteritis with intimal fibrin ring and immature myeloid cell infiltrate: lymphocytic thrombophilic arteritis or histiocytoid polyarteritis nodosa?

The ongoing debate on whether lymphocytic thrombophilic arteritis (LTA) is a separate disease or a type of polyarteritis nodosa (PAN) has yet to be settled. In this study, we analyzed the nature of infiltrating cells in LTA to resolve this controversy. Skin biopsies from five female patients (mean age 29.4 years, age range 16-45 years) diagnosed with LTA were immunostained for CD3, CD20, CD68, lysozyme, myeloid cell nuclear differentiation antigen, myeloperoxidase, and PU.1. Immunohistochemistry revealed that the majority of mononuclear cells in all five cases were not lymphocytes but myelomonocytic cells. Given that the infiltrating cells are of the myelomonocyte lineage including immature myeloid cells, PAN was deemed the more appropriate diagnosis for the five cases rather than LTA. Whether PAN with immature myeloid cells (histiocytoid PAN) is the same disease as conventional PAN with mature neutrophils requires further investigation.

An autopsy case of hyperimmunoglobulin E syndrome with coronary fibrinoid necrotizing arteritis and an aneurysm.

We report a case of hyperimmunoglobulin (Ig) E syndrome (HIES) with a coronary artery aneurysm (CAA) in a 25-year-old Japanese man. He died suddenly due to chronic heart failure associated with HIES. We noted a CAA at the trunk of the left coronary artery and granulomatous and fibrinoid necrotizing arteritis of the middle portion of the left anterior descending during the autopsy. We speculate herein on the relationship between the aneurysm and arteritis. These findings facilitate a better understanding of the pathogenesis underlying HIES.

Regulatory T Cells in Autoimmune Vasculitis.

Blood vessels are indispensable for host survival and are protected from inappropriate inflammation by immune privilege. This protection is lost in patients with autoimmune vasculitides, a heterogeneous group of diseases causing damage to arteries, arterioles, and capillaries. Vasculitis leads to vascular wall destruction and/or luminal occlusion, resulting in hemorrhage and tissue ischemia. Failure in the quantity and quality of immunosuppressive regulatory T cells (Treg) has been implicated in the breakdown of the vascular immune privilege. Emerging data suggest that Treg deficiencies are disease-specific, affecting distinct pathways in distinct vasculitides. Mechanistic studies have identified faulty CD8+ Tregs in Giant Cell Arteritis (GCA), a vasculitis of the aorta and the large aortic branch vessels. Specifically, aberrant signaling through the NOTCH4 receptor expressed on CD8+ Treg cells leads to rerouting of intracellular vesicle trafficking and failure in the release of immunosuppressive exosomes, ultimately boosting inflammatory attack to medium and large arteries. In Kawasaki's disease, a medium vessel vasculitis targeting the coronary arteries, aberrant expression of miR-155 and dysregulated STAT5 signaling have been implicated in undermining CD4+ Treg function. Explorations of mechanisms leading to insufficient immunosuppression and uncontrolled vascular inflammation hold the promise to discover novel therapeutic interventions that could potentially restore the immune privilege of blood vessels and pave the way for urgently needed innovations in vasculitis management.

A case of IgA vasculitis with necrotizing arteritis in a 13-year-old girl.

IgA vasculitis (IgAV) is the most frequent form of vasculitis in childhood which classically presents with purpura of the lower extremities, joint pain or swelling and abdominal pain. Though it is a self-limiting disease, and its prognosis is generally good, glomerulonephritis is one of the most important complications. IgAV is classified as a small vessel vasculitis, and though glomerulonephritis develops in IgAV, necrotizing arteritis is rarely seen. Here, we present a case of a 13-year-old girl with IgAV, glomerulonephritis, and necrotizing arteritis in the small renal arteries. There have been only a few reports of adult cases of IgAV with necrotizing arteritis in the kidneys, but there have been no pediatric cases. Some previous reports showed a high mortality rate and implied the possibility of overlap with other vasculitides. In the current report, a rare case of IgAV is described which exhibited necrotizing arteritis rather than overlap with another vasculitis, with a relatively typical clinical course for IgAV and laboratory tests.

Clinical presentations and long term prognosis of childhood onset polyarteritis nodosa in single centre of Korea.

Childhood-onset polyarteritis nodosa (PAN) is a rare and systemic necrotising vasculitis in children affecting small- to medium-sized arteries. To date, there have been only a few reports because of its rarity. Thus, we aimed to investigate the clinical manifestations, laboratory findings, treatment, and long-term outcomes in patients with childhood-onset PAN and to evaluate the usefulness of the paediatric vasculitis activity score (PVAS). We retrospectively analysed the data of nine patients with childhood-onset PAN from March 2003 to February 2020. The median ages at symptom onset, diagnosis, and follow-up duration were 7.6 (3-17.5), 7.7 (3.5-17.6), and 7.0 (1.6-16.3) years, respectively. All patients had constitutional symptoms and skin manifestations, while five exhibited Raynaud's phenomenon. Organ involvement was observed in one patient. The median PVAS at diagnosis was 7 (range: 2-32). Prednisolone was initially used for induction in all patients, and other drugs were added in cases refractory to prednisolone. All patients survived, but three patients with high PVAS at diagnosis experienced irreversible sequelae, including intracranial haemorrhage and digital amputation. In conclusion, early diagnosis and treatment may minimise sequelae in patients with childhood-onset PAN. This study suggests that high PVAS score at diagnosis may be associated with poor prognosis.

Fluctuating facial edema as a rare manifestation of cutaneous polyarteritis nodosa: Case report and review of the literature.

Polyarteritis nodosa (PAN) is a necrotizing vasculitis. The clinical manifestations are determined by the location of the compromised arteries. Cutaneous PAN can present as nodular lesions similar to erythema nodosum, palpable purpura, livedo reticularis, and ulceration. It often affects the lower limbs but other anatomical sites can also be involved. However, concomitant facial edema is an extremely rare manifestation. It has been more than 20 years since the last case report describing this unusual presentation of PAN. Furthermore, our patient is the first case presenting with hemifacial edema fluctuating every second or third day due to PAN confirmed by skin biopsy.

The ratio of CD163-positive macrophages to Iba1-positive macrophages is low in the intima in the early stage of cutaneous arteritis.

The etiology of polyarteritis nodosa (PAN) and localized PAN, including cutaneous arteritis (CA), remains unknown; however, initial endothelial damage has been implicated. The intima of the vasculitis lesions is predominantly infiltrated by innate-like bystander-activated CD8 T cells, in addition to the macrophages. Macrophages are among the major inflammatory cells involved in innate immunity and are classified into M1 and M2 subtypes. M1-type macrophages kill pathogens and cause inflammation, while M2-type macrophages promote the repair of tissues. Macrophage subtypes infiltrating in PAN and localized PAN vasculitis lesions have not yet been investigated. Innate immune response to a triggering factor on the endothelial cell surface may initiate CA pathogenesis. Thus, many M1-type macrophages may infiltrate in the intima during early CA. We assessed this hypothesis by immunohistochemical observation of macrophage phenotypes and polarization. Twenty-seven skin biopsy specimens from patients with CA were retrieved. Based on histology, we classified CA into four phases. The phenotypes of infiltrating macrophages in CA were evaluated by immunohistochemistry using antibodies against Iba-1, a pan-macrophage marker, and CD163, an M2-type macrophage marker. Our results showed that the ratio of CD163-positive M2-type macrophages to Iba1-positive macrophages was lower in the intima in the early stage of CA than in the later stage. In the media to adventitia, there was no significant difference in the ratios between these stages. These findings indicate that innate immunity is involved in the intima in the early stage of CA, suggesting that a trigger for CA might exist in endothelial cells.

Survey of Japanese dermatological vasculitis specialists on cases of cutaneous arteritis (cutaneous polyarteritis nodosa).

We developed a questionnaire to examine the findings of cutaneous arteritis among dermatological specialists experienced in vasculitis as certified by the Committee for guidelines for the management of vasculitis and vascular disorders of the Japanese Dermatological Association. We sent a questionnaire to 12 dermatological facilities identified through the revised Committee for guidelines for the management of vasculitis and vascular disorders of the Japanese Dermatological Association. Retrospective data obtained from 84 patients at the 12 dermatological facilities between 2012 January 2016 December were evaluated. The 84 patients were categorized into two groups, a systemic steroid treatment group (group 1, n = 52) and a no systemic steroid treatment group (group 2, n = 32). C-reactive protein in group 1 patients was significantly higher than that in group 2 patients. Frequency of fever, arthritis, myalgia- and peripheral neuropathy in group 1 was significantly higher than that in group 2. We propose that these symptoms could serve as early markers for the transfer from cutaneous arteritis to systemic polyarteritis nodosa. We further suggest that patients who are subsequently associated with cerebral hemorrhage and infarction, who are originally diagnosed as having cutaneous arteritis, could progress to systemic polyarteritis nodosa. The study demonstrated that it is important for dermatologists to detect these findings early in order to establish an accurate diagnosis and a timely treatment.

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

BACKGROUND: Lymphocytic thrombophilic arteritis (LTA), or macular lymphocytic arteritis, is defined by a primary lymphocytic vasculitis. However, the nosology of LTA has been controversial, with speculation that it may represent an indolent non-nodule-forming variant of cutaneous polyarteritis nodosa (cPAN). OBJECTIVE: This study compares the clinicopathologic features of patients with LTA or cPAN to assess if these conditions should be considered distinct entities. METHODS: This is a cross-sectional study of all LTA and cPAN cases at a single tertiary center using prospectively collected clinical data and blinded histologic assessment. RESULTS: The study included 17 patients with LTA and 13 patients with cPAN. Clinically, cases of LTA were distinguished by a more widespread pattern of livedo racemosa, which was noninfiltrated and asymptomatic. In contrast, cPAN was associated with localized starburst livedo, purpura, and episodic features including nodules, pain, and large inflammatory ulcers. When patients were separated according to the presence (>5%) or paucity (≤5%) of neutrophils on blinded histology review, they had distinct clinical features and differences in disease course. LIMITATIONS: This was a single-center study. CONCLUSION: Our data support the classification of LTA and cPAN as separate entities rather than a spectrum of the same disorder and highlight the importance of clinicopathologic correlation in distinguishing these conditions.

Is macular lymphocytic arteritis limited to the skin? Long-term follow-up of seven patients

Abstract Background: Macular lymphocytic arteritis most commonly presents as hyperpigmented macules on the lower limbs. The pathogenesis of this disease is still unclear and there is an ongoing debate regarding whether it represents a new form of cutaneous vasculitis or an indolent form of cutaneous polyarteritis nodosa. Objective: To describe clinical, histopathological, and laboratory findings of patients with the diagnosis of macular lymphocytic arteritis. Methods: A retrospective search was conducted by reviewing cases followed at the Vasculitis Clinic of the Dermatology Department, School of Medicine, University of São Paulo, between 2005 and 2017. Seven patients were included. Results: All cases were female, aged 9-46 years, and had hyperpigmented macules mainly on the legs. Three patients reported symptoms. Skin biopsies evidencing a predominantly lymphocytic infiltrate affecting arterioles at the dermal subcutaneous junction were found, as well as a typical luminal fibrin ring. None of the patients developed necrotic ulcers, neurological damage, or systemic manifestations. The follow-up ranged from 18 to 151 months, with a mean duration of 79 months. Study limitations: This study is subject to a number of limitations: small sample of patients, besides having a retrospective and uncontrolled study design. Conclusions: To the best of the authors' knowledge, this series presents the longest duration of follow-up reported to date. During this period, none of the patients showed resolution of the lesions despite treatment, nor did any progress to systemic vasculitis. Similarities between clinical and skin biopsy findings support the hypothesis that macular lymphocytic arteritis is a benign, incomplete, and less aggressive form of cutaneous polyarteritis nodosa.

Is macular lymphocytic arteritis limited to the skin? Long-term follow-up of seven patients.

BACKGROUND: Macular lymphocytic arteritis most commonly presents as hyperpigmented macules on the lower limbs. The pathogenesis of this disease is still unclear and there is an ongoing debate regarding whether it represents a new form of cutaneous vasculitis or an indolent form of cutaneous polyarteritis nodosa. OBJECTIVE: To describe clinical, histopathological, and laboratory findings of patients with the diagnosis of macular lymphocytic arteritis. METHODS: A retrospective search was conducted by reviewing cases followed at the Vasculitis Clinic of the Dermatology Department, School of Medicine, University of São Paulo, between 2005 and 2017. Seven patients were included. RESULTS: All cases were female, aged 9-46 years, and had hyperpigmented macules mainly on the legs. Three patients reported symptoms. Skin biopsies evidencing a predominantly lymphocytic infiltrate affecting arterioles at the dermal subcutaneous junction were found, as well as a typical luminal fibrin ring. None of the patients developed necrotic ulcers, neurological damage, or systemic manifestations. The follow-up ranged from 18 to 151 months, with a mean duration of 79 months. STUDY LIMITATIONS: This study is subject to a number of limitations: small sample of patients, besides having a retrospective and uncontrolled study design. CONCLUSIONS: To the best of the authors' knowledge, this series presents the longest duration of follow-up reported to date. During this period, none of the patients showed resolution of the lesions despite treatment, nor did any progress to systemic vasculitis. Similarities between clinical and skin biopsy findings support the hypothesis that macular lymphocytic arteritis is a benign, incomplete, and less aggressive form of cutaneous polyarteritis nodosa.

Aberrant Mesenteric Migration of Spirocerca lupi Larvae Causing Necrotizing Eosinophilic Arteritis, Thrombosis, and Intestinal Infarction in Dogs.

This report presents a novel canine condition in 32 dogs in which aberrant migration of Spirocerca lupi larvae through mesenteric arteries, instead of gastric arteries, led to small or large intestinal infarction. This form of spirocercosis was first recognized in Israel in 2013 and is currently ongoing. Typical clinical signs were anorexia and weakness of 3 to 4 days and, less frequently, vomiting and diarrhea, followed by collapse, bloody diarrhea, and severe vomiting. Exploratory laparotomy showed 1 or more infarcted and often perforated intestinal segments in all cases. Microscopically, there was intestinal mucosal to transmural coagulative necrosis and mesenteric multifocal necrotizing eosinophilic arteritis, thrombosis, hemorrhage, and early fibroplasia. Third-stage S. lupi larvae were identified by morphologic features in 9 of 32 (28%) cases, and the species was confirmed by polymerase chain reaction in 4 cases. Nearly 50% of the dogs had been receiving prophylactic therapy, which did not prevent this form of spirocercosis.

Skin Picking Disorder in a Woman with Polyarteritis Nodosa. Case Report. / Trastorno de excoriación en una mujer con panarteritis nudosa. Reporte de caso.

INTRODUCTION: Excoriation (skin picking) disorder is included in the DSM-5 in the obsessive compulsive and related disorders category. It is defined as the recurrent urge to touch, scratch, scrape, scrub, rub, squeeze, bite or dig in the skin, leading to skin lesions. It is a rare disorder (1.4-5.4% of the population) and occurs mainly in women. CASE REPORT: this article reports the case of a 31-year-old female patient, initially assessed by dermatology and orthopaedics for the presence of infected ulcerated lesions on her lower limbs, with other superficial lesions from scratching on her chest, arms, forearms, back and head. The patient also reported symptoms of anxiety, so was assessed by consultation-liaison psychiatry. DISCUSSION: skin picking, normal behaviour in mammals, becomes pathological from a psychiatric point of view when it is repetitive and persistent, as in the case of excoriation disorder. In view of the reported relationship with the obsessive-compulsive spectrum, use of selective serotonin reuptake inhibitors and cognitive behavioural therapy are recommended.

Polyarteritis nodosa isolated to the testis and urinary bladder in the setting of cryptorchidism: a case report and literature review.

BACKGROUND: Polyarteritis nodosa is a small vessel to medium vessel vasculitis that frequently presents with multi-organ involvement, but can sometimes be limited to single organs such as the testes. Patients often require treatment with glucocorticoids, plus or minus additional immunosuppressive therapy depending on the severity of the disease. We describe a rare case of polyarteritis nodosa involving the right testis and urinary bladder without other systemic features of vasculitis. CASE PRESENTATION: A previously healthy 54-year-old First Nations Canadian man presented with intermittent gross hematuria. He underwent surgical excision of his right testis for cryptorchidism and a transurethral resection of a bladder mass. Histology showed an active medium vessel vasculitis in both organs. On extensive clinical, laboratory, and radiographic review, he had no systemic features of vasculitis. On 2-year follow-up, he has not required any systemic therapy and has not developed further symptoms. CONCLUSION: Single organ polyarteritis nodosa can sometimes be managed with surgical excision of the involved organ alone. Although our patient had two organs involved, we extrapolated the results of our literature search to guide his care. This case highlights the potential for surgical excision to cure polyarteritis nodosa despite the involvement of two organs in the absence of symptoms and signs of systemic vasculitis.