Clinical spectrum and outcome of children with deficiency of adenosine deaminase 2 (DADA2): multicentric experience from India.

OBJECTIVES: Deficiency of adenosine deaminase-2 (DADA2) is a monogenic disorder closely resembling polyarteritis nodosa (PAN) and can present to physicians across various specialties. Through this case series, we aim to describe the clinical spectrum and outcome of Indian children with DADA2. We aimed to study the clinical spectrum and outcome of Indian children with DADA-2. METHODS: The deidentified data from all participating centres were entered in an excel sheet, and the coordinating centre (All India Institute of Medical Sciences, New Delhi) screened the data for accuracy and completeness. RESULTS: We enrolled 16 children (11 females) in the study; the mean (SD) age at the time of onset of symptoms for males and females was 46.2 (47) and 73.6 (50.4) months, respectively. The most common clinical feature in this cohort was fever and rash in 80% of patients. More than half of children n, (%) [8, (53%)] had a CNS stroke. The other clinical features were hypertension [5(33%)], anaemia [3 (20%)] and arthralgia/arthritis in 4 (26%). These children were managed with various immunomodulators: steroids [13, (86%)], anti-TNF agents [(12, (80%)], cyclophosphamide [2 (13%)] and mycophenolate mofetil [3 (20%)]. The median (IQR) duration of follow-up for this cohort was 17 (10, 29) months. Fourteen children achieved remission and none had recurrent strokes after the initiation of anti-TNF drugs. CONCLUSION: DADA-2 closely resembles PAN; early age of onset and CNS stroke are striking differentiating features from classic PAN. Most children respond well to anti-TNF agents without serious adverse events during short-term follow-up.

[Vasculitic involvement of the skeletal muscle and the peripheral nervous system: clinical and neuropathologic perspective]. / Vaskulitische Beteiligung der Skelettmuskulatur und des peripheren Nervensystems: Klinische und neuropathologische Perspektive.

The peripheral nervous system is a classic target organ in systemic vasculitis. In addition, the skeletal muscle can also be affected. Myalgia, muscle weakness and sensory deficits are typical signs, which can lead to severe functional limitations and impaired of quality of life. Vasculitic involvement of the skeletal muscle (vasculitic myopathy [VM]) and peripheral nerves (vasculitic neuropathy [VN]) occurs predominantly in polyarteritis nodosa and small-vessel vasculitis. VM presents with elevated markers of inflammation and is typically characterized by immobilizing myalgia with normal creatine kinase activity and diffuse or patchy areas of hyperintensity on T2-weighted MRI ("MRI myositis without myositis"). In VN, sensor motor deficits predominantly affect the lower extremity in the area supplied by several peripheral nerves (e.g., mononeuritis multiplex) with acute to subacute history. The histopathological examination of nerve and muscle biopsies is the gold standard for the diagnosis of vasculitic manifestations and has a significant impact on the therapeutic approach.

Early skeletal muscle manifestations in polyarteritis nodosa and ANCA-associated vasculitis.

Skeletal muscle involvement is common in patients with small- and medium-sized vasculitis, particularly polyarteritis nodosa (PAN) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Despite being not included in the standard classification criteria for PAN and AAV, skeletal muscle involvement is an important clinical indicator, particularly when vasculitic myopathy is the only pathological evidence in the absence of other organ involvement. Herein, we comprehensively reviewed and compared the clinical features of 71 and 135 patients with PAN and AAV, respectively, with skeletal muscle involvement at the time of disease onset. Most patients with PAN and AAV exhibited skeletal muscle involvement, often characterized by myalgia and occasional muscular weakness, predominantly in the lower extremities. Myalgia and weakness were observed more frequently in the distal lower extremities in patients with PAN than in those with AAV. In contrast, skeletal muscle involvement tended to exhibit a more dispersed distribution across all four extremities in those with AAV. Muscle magnetic resonance imaging T2-weighted and short-tau inversion recovery sequences can effectively identify hyperintense areas attributed to hypervascularity of affected muscle tissues and serve as a sensitive and useful modality for visually determining the suitable biopsy site. >90% of patients with PAN and AAV demonstrated perivascular inflammation in their affected muscle tissues, whereas fibrinoid necrosis of the vessel walls was reported in two-thirds of patients. Serum creatine kinase (CK) levels were within the normal range in approximately 80% of patients presenting with skeletal muscle involvement in PAN and AAV. Furthermore, muscle fiber damage was milder in patients with skeletal muscle involvement in PAN and AAV than those with idiopathic inflammatory myositis. Meanwhile, serum CK levels were elevated in 65-85% of patients with PAN and AAV who had myofiber necrosis and degeneration in the affected muscles. Most patients with PAN and AAV showed improvement in skeletal muscle involvement following glucocorticoids (GCs) administration; however, relapse was observed in some patients during the tapering of GCs. In summary, skeletal muscle involvement is a potential indicator for establishing PAN and AAV diagnoses during the early phases of the disease.

Possible usefulness of fluorodeoxyglucose positron emission tomography in diagnosing polyarteritis nodosa: A case report and literature review.

Polyarteritis nodosa (PAN) is a systemic rheumatic disease that affects medium-sized arteries. PAN is typically not associated with anti-neutrophil cytoplasmic antibodies and has no serological surrogate markers. Therefore, its diagnosis requires pathological findings. However, the positive rate of biopsy in diagnosing PAN is not high, and the biopsy area is often limited. Several investigators have reported the usefulness of imaging findings in diagnosing PAN, independent of pathological findings. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET)/CT has recently been approved for the diagnosis of large-vessel vasculitis in Japan. Several studies have also demonstrated the usefulness of FDG-PET/CT in diagnosing medium-vessel vasculitis. However, no studies have evaluated the usefulness of FDG-PET/CT for diagnosing PAN compared to other modalities, and it is not clear whether FDG-PET/CT is superior to other modalities for diagnosing PAN. Herein, we report a case of PAN and compare the usefulness of FDG-PET/CT with other modalities in diagnosing PAN.

Adalimumab-induced leukocytoclastic vasculitis in a patient with ankylosing spondylitis: A case report.

Clinical Key Message: In patients receiving anti-TNF-α drugs for ankylosing spondylitis, monitoring purpuric and ischemic skin lesions is crucial. This case underscores the significance of identifying and addressing drug-induced vasculitis while stressing the necessity for prompt evaluation and exploration of alternative treatment options to safeguard patient well-being. Abstract: The case discusses a 38-year-old female with a history of ankylosing spondylitis (AS) who presented with skin lesions, including purpuric skin lesions and ischemia of her right foot digits, after initiating treatment with adalimumab. After excluding other potential causes, such as infections and malignancies, the patient received a diagnosis of moderate-sized vascular vasculitis associated with adalimumab use. Discontinuation of adalimumab and treatment with high dose glucocorticoids and intravenous pulse of cyclophosphamide resulted in the resolution of her ischemic lesions. This case underscores the importance of considering drug-related side effects in patients with new skin lesions, particularly in the context of rheumatic diseases such as AS.

Genetics of vasculitis.

Systemic vasculitis encompasses a wide range of conditions characterized by varying degrees of inflammation in blood vessels. Although the etiology of vasculitis remains unclear, accumulated data suggest that it is triggered in genetically predisposed individuals by the concurrence of certain environmental factors. The importance of the genetic component has been consistently supported by evidence of familial aggregation, differential prevalence by ethnicity, and multiple genetic associations with disease susceptibility and severity reported in recent years. The strongest association signals in most vasculitides correspond to genetic variants within the HLA region, suggesting an important role of the immune system in its pathophysiology. However, each type of vasculitis has distinct defining HLA association markers, likely due to disease-specific differences in antigenic drivers. Furthermore, other genetic polymorphisms located outside the HLA region play an important role in susceptibility to different vasculitides. More recent research has assessed the shared genetic susceptibility evident across different vasculitides. Future studies should focus on the identification of genetic markers that can serve as reliable biomarkers for early diagnosis, prognosis, and treatment response in systemic vasculitis.

Case report of streptococcal infection as a potential precipitating factor in cutaneous polyarteritis nodosa in pediatric patients.

Key Clinical Message: This pediatric case report underscores the importance of maintaining a high clinical suspicion for polyarteritis nodosa (PAN) in patients presenting with atypical features, such as migratory arthritis and subcutaneous nodules. Importantly, it highlights the focus on the potential relationship between streptococcal infection and cutaneous PAN. Early recognition and prompt, aggressive treatment is critical, as PAN can be a life-threatening condition if left unmanaged. This case emphasizes the need for a multidisciplinary approach to effectively identify and manage this rare vasculitis disorder in the pediatric population. Abstract: Polyarteritis nodosa (PAN) is a rare and life-threatening vasculitis with diverse clinical presentations, posing a diagnostic challenge. Early recognition and prompt intervention are crucial to prevent organ damage. We present the case of an 8-year-old boy who exhibited atypical symptoms including migratory arthritis, myalgia, digital discoloration and ischemic changes, and subcutaneous nodules. Initial concerns for septic arthritis were ruled out. A comprehensive evaluation revealed elevated inflammatory markers and a confirmatory skin biopsy demonstrating active leukocytoclastic vasculitis, are highly suggestive of a diagnosis of PAN. Notably, elevated ASO titers suggested a possible concurrent streptococcal infection. The aggressive treatment approach with high-dose aspirin, steroids, methotrexate, and tocilizumab is justified given the severity of the patient's symptoms and the nature of the disease process. This case underscores the importance of considering PAN in the differential diagnosis for children presenting with atypical features. Early diagnosis and prompt intervention, including addressing potential infectious triggers, are crucial for optimal outcomes in pediatric PAN.

Rapidly Progressive, Symmetrical, Acute Cutaneous Necrosis of Bilateral Lower Limbs: A Rare Presentation of Polyarteritis Nodosa.

Acute cutaneous necrosis is a rare presentation of polyarteritis nodosa (PAN). In this study, we report a presentation with symmetrical cutaneous necrosis of the lower limbs, which ascended upward at a rapid rate. A 47-year-old man presented with a fever of one day and pain in the feet for six days. He had no history of claudication. Upon examination, he was febrile, and subtle bluish discoloration was observed on the sole of his foot. There was a bilateral stocking-type paresthesia up to the ankle joint. His blood pressure on admission was 210/120 mmHg. Eight hours later, the pain subsided, but a left-sided foot drop was noted along with the paresthesia extending up both feet to approximately 10 cm above the medial malleolus. The feet turned black, and dark discoloration spread rapidly upward over the next 16 hours, and the skin became necrosed. A clinical diagnosis of vasculitis was established, and the patient received IV methylprednisolone at a daily dosage of 1 g for three days, effectively stopping the advancement of necrosis. This was followed by treatment with IV cyclophosphamide. A conclusive diagnosis of PAN was made, and the patient underwent wound debridement. After three months of physiotherapy, a successful skin graft was performed. Prompt identification of the underlying etiology is crucial to prevent the advancement of necrosis and save the limbs. When vasculitis is suspected, ruling out infectious causes is essential before starting early immunosuppressive treatment.

Anti-LAMP-2 Antibody Seropositivity in Children with Primary Systemic Vasculitis Affecting Medium- and Large-Sized Vessels.

Chronic primary systemic vasculitis (PSV) comprises a group of heterogeneous diseases that are broadly classified by affected blood vessel size, clinical traits and the presence (or absence) of anti-neutrophil cytoplasmic antibodies (ANCA) against proteinase 3 (PR3) and myeloperoxidase (MPO). In small vessel vasculitis (SVV), ANCA are not present in all patients, and they are rarely detected in patients with vasculitis involving medium (MVV) and large (LVV) blood vessels. Some studies have demonstrated that lysosome-associated membrane protein-2 (LAMP-2/CD107b) is a target of ANCA in SVV, but its presence and prognostic value in childhood MVV and LVV is not known. This study utilized retrospective sera and clinical data obtained from 90 children and adolescents with chronic PSV affecting small (SVV, n = 53), medium (MVV, n = 16), and large (LVV, n = 21) blood vessels. LAMP-2-ANCA were measured in time-of-diagnosis sera using a custom electrochemiluminescence assay. The threshold for seropositivity was established in a comparator cohort of patients with systemic autoinflammatory disease. The proportion of LAMP-2-ANCA-seropositive individuals and sera concentrations of LAMP-2-ANCA were assessed for associations with overall and organ-specific disease activity at diagnosis and one-year follow up. This study demonstrated a greater time-of-diagnosis prevalence and sera concentration of LAMP-2-ANCA in MVV (52.9% seropositive) and LVV (76.2%) compared to SVV (45.3%). Further, LAMP-2-ANCA-seropositive individuals had significantly lower overall, but not organ-specific, disease activity at diagnosis. This did not, however, result in a greater reduction in disease activity or the likelihood of achieving inactive disease one-year after diagnosis. The results of this study demonstrate particularly high prevalence and concentration of LAMP-2-ANCA in chronic PSV that affects large blood vessels and is seronegative for traditional ANCA. Our findings invite reconsideration of roles for autoantigens other than MPO and PR3 in pediatric vasculitis, particularly in medium- and large-sized blood vessels.

Multi-Modality Imaging in Vasculitis.

Systemic vasculitides are a rare and complex group of diseases that can affect multiple organ systems. Clinically, presentation may be vague and non-specific and as such, diagnosis and subsequent management are challenging. These entities are typically classified by the size of vessel involved, including large-vessel vasculitis (giant cell arteritis, Takayasu's arteritis, and clinically isolated aortitis), medium-vessel vasculitis (including polyarteritis nodosa and Kawasaki disease), and small-vessel vasculitis (granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis). There are also other systemic vasculitides that do not fit in to these categories, such as Behcet's disease, Cogan syndrome, and IgG4-related disease. Advances in medical imaging modalities have revolutionized the approach to diagnosis of these diseases. Specifically, color Doppler ultrasound, computed tomography and angiography, magnetic resonance imaging, positron emission tomography, or invasive catheterization as indicated have become fundamental in the work up of any patient with suspected systemic or localized vasculitis. This review presents the key diagnostic imaging modalities and their clinical utility in the evaluation of systemic vasculitis.

Shifting perspectives in coronary involvement of polyarteritis nodosa: case of 3-vessel occlusion treated with 4-vessel CABG and review of literature.

BACKGROUND: Polyarteritis Nodosa (PAN) is a systemic vasculitis (SV) historically thought to spare the coronary arteries. Coronary angiography and contemporary imaging reveal coronary stenosis and dilation, which are associated with significant morbidity and mortality. Coronary arteries in PAN are burdened with accelerated atherosclerosis from generalized inflammation adding to an inherent arteritic process. Traditional atherosclerotic risk factors fail to approximate risk. Few reports document coronary pathology and optimal therapy has been guarded. METHODS: Database publication query of English literature from 1990-2022. RESULTS: Severity of coronary involvement eludes laboratory monitoring, but coronary disease associates with several clinical symptoms. Framingham risk factors inadequately approximate disease burden. Separating atherosclerosis from arteritis requires advanced angiographic methods. Therapy includes anticoagulation, immunosuppression and revascularization. PCI has been the mainstay, though stenting is confounded by vagarious alteration in luminal diameter and reports of neointimization soon after placement. CONCLUSIONS: When graft selection avoids the vascular territory of SV's, CABG offers definitive therapy. We have contributed report of a novel CABG configuration in addition to reviewing, updating and discussing the literature. Accumulating evidence suggests discrete clinical symptoms warrant suspicion for coronary involvement.

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.

Post COVID-19 vaccination medium vessel vasculitis: a systematic review of case reports.

PURPOSE: Vaccinations are essential in minimizing the effects of global health crises including COVID-19 pandemic. This study investigates the potential association between COVID-19 vaccination and the occurrence of medium vessel vasculitis. METHODS: Several databases were utilized to conduct a comprehensive literature review. The studies were carefully evaluated to ensure their quality and eliminate any potential bias. RESULTS: After reviewing 935 search results and removing duplicates, we selected 10 case reports. We discovered that medium vessel vasculitis may occur after COVID-19 vaccination, typically appearing around 16.2 days after vaccination. The patients in the study had a median age of 43.5 years and were predominantly males (80%). Additionally, half of the cases were reported after the second dose of vaccination. CONCLUSIONS: Vaccination-associated vasculitis is a rare yet possible complication of COVID-19 vaccination and lacks a clear treatment protocol.

Comparison of characteristics of muscle magnetic resonance imaging findings in patients with antineutrophilic cytoplasmic antibody-associated vasculitis and polyarteritis nodosa.

AIM: This study aimed to analyze the muscle magnetic resonance imaging (MRI) findings of patients with antineutrophilic cytoplasmic antibody-associated vasculitis (AAV) and polyarteritis nodosa (PAN) presenting with clinical symptoms in the extremities. METHODS: Retrospective analysis was conducted on short tau inversion recovery MRI findings, with a focus on intramuscular vessels displaying abnormal perivascular signals, in 22 and eight patients with AAV and PAN, respectively. The number per unit area (4 cm2) and diameter of abnormal vessels on muscle MRI were compared between patients with AAV and those with PAN. Cut-off values, clinical sensitivity, and specificity for these indices were calculated from the receiver operating characteristic curves to distinguish between AAV and PAN, and the relationship between the indices and clinical findings in AAV was analyzed. RESULTS: The number of abnormal vessels per unit area was significantly higher in AAV compared to PAN (p < .05). Additionally, the diameter of the abnormal vessels was significantly higher in PAN than in AAV (p < .05). The presence of >6.44 abnormal vessels per unit area or ≤3.61 mm diameter of abnormal vessels was able to predict AAV (sensitivity, 0.955; specificity, 0.625). AAV patients with peripheral neuropathy exhibited a significantly higher number of abnormal vessels per unit area than those without peripheral neuropathy (p < .05). CONCLUSIONS: Muscle MRI can detect small- to medium-vessel vasculitis and be a valuable tool for distinguishing between patients with AAV and PAN experiencing clinical symptoms in the extremities.

Ruptured Saccular Aneurysm Caused by Necrotizing Arteritis of the Polyarteritis Nodosa Type in Primary Angiitis of Central Nervous System.

Primary angiitis of central nervous system (PACNS) is a rare idiopathic vasculitis that typically involves small arteries. An 18-year-old woman was operated on for resection of a ruptured aneurysm in a cerebral artery. Multiple aneurysms of cerebral arteries had been detected by neuroimaging examinations since the age of 12, and she had been administered drugs following a diagnosis of PACNS since the age of 15. The resected aneurysm was a ruptured saccular aneurysm occurring in a medium-sized artery. Histologically, necrotizing arteritis of the polyarteritis nodosa (PAN) type was noted in the aneurysmal wall. It consisted of an admixture of acute and healing stages. In the acute stage, fibrinoid necrosis in the intima and media and intense inflammatory cell infiltrate in the entire wall were present. The inflammatory cells mainly consisted of lymphocytes, including plasma cells, neutrophils, and macrophages. In the healing stage, disappearance of fibrinoid necrosis, fibrosis in the intima and media, and scarce inflammatory cells were noted. The acute stage was mainly present near the ruptured site. From these findings, the aneurysm was considered to have been caused by necrotizing arteritis of the PAN type. Although saccular aneurysmal formation in a medium-sized artery is rare in PACNS, an understanding of aneurysms produced by necrotizing arteritis of the PAN type offers useful information for the diagnosis and treatment of PACNS.

Nationwide epidemiological survey of polyarteritis nodosa in Japan in 2020.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that predominantly affects medium-sized arteries. With advances in our understanding of the pathogenesis and classification of vasculitis, PAN and microscopic polyangiitis (MPA), a disease of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), were separated from the group of diseases previously diagnosed as periarteritis nodosa (PN) at the Chapel Hill Consensus Conference (CHCC) in 1994 (1).

Cutaneous nodular polyarteritis presenting as refractory ulcers on both lower extremities: A case report.

BACKGROUND: Cutaneous polyarteritis nodosa (cPAN) is a systemic disease that is limited to the skin. cPAN usually presents with cutaneous reticular cyanotic, erythematous and palpable nodules, and cutaneous ulcers.Research has indicated that the use of hormones and immunosuppressive drugs can delay ulcer healing and associated neuropathy, and also elevate the risk of disease recurrence upon their reduction or withdrawal. Therefore, it is a necessary to find a safe and effective approach that minimize hormone side effects in ulcer treatment. CASE PRESENTATION: The patient, a 48-year-old female of Han Chinese ethnicity, has suffered from recurrent erythema nodosum on both lower limbs for 8 years. The condition was aggravated by skin breakdown over the last 3 months. Despite multiple treatments, the patient's condition did not improve significantly, leading to the exploration of a combined approach of traditional Chinese and Western medicine. Following six months of combined traditional Chinese and Western medicine treatment, t the patient's newborn erythema and ulcers on both lower limbs did not reappear, and the ulcers gradually decreased in size and the erythema disappeared. The patient took the TCM regularly until April 15, 2023, when the ulcers were completely healed. Three months after the patient stopped taking TCM, the ulcers had completely healed with no recurrence, as observed during the follow-up visit on July 14th, 2023. CONCLUSION: Traditional Chinese Medicine Combined with Low-Dose Hormones May Effectively Treat Bilateral Lower Extremity Skin Ulcers Caused by Cutaneous Polyarteritis Nodosa.

[Mononeuropathy multiplex caused by cutaneous arteritis diagnosed by skin biopsies for emerging atypical erythema on upper limbs following neurological symptoms: a case report].

A 33-year-old female was admitted to our department complaining of multifocal paresthesia and weakness of the upper and lower extremities that had developed over the previous three months. She had also been undergoing treatment for atopic dermatitis with dupilumab, an anti-interleukin 4/13 receptor antibody. A nerve conduction study revealed multifocal axonal sensorimotor neuropathy of bilateral limbs. On admission, a small erythema appeared on her right forearm, but it was atypical for vasculitic skin lesions due to its location and time course. Nonetheless, a biopsy revealed medium-sized vessel vasculitis. The patient was therefore diagnosed with vasculitic neuropathy caused by cutaneous arteritis. Methylprednisolone pulse therapy with prednisolone and azathioprine markedly improved her symptoms. A skin biopsy is useful when mononeuropathy multiplex is suspected, even if the skin findings are atypical for vasculitic rash.

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.

Polyarteritis Nodosa: Old Disease, New Etiologies.

Polyarteritis nodosa (PAN), also known as panarteritis nodosa, represents a form of necrotizing vasculitis that predominantly affects medium-sized vessels, although it is not restricted to them and can also involve smaller vessels. The clinical presentation is heterogeneous and characterized by a significant number of patients exhibiting general symptoms, including asthenia, fever, and unintended weight loss. Although PAN can involve virtually any organ, it preferentially affects the skin, nervous system, and the gastrointestinal tract. Orchitis is a rare but specific manifestation of PAN. The absence of granulomas, glomerulonephritis, and anti-neutrophil cytoplasmic antibodies serves to distinguish PAN from other types of vasculitis. Major complications consist of hemorrhagic and thrombotic events occurring in mesenteric, cardiac, cerebral, and renal systems. Historically, PAN was frequently linked to hepatitis B virus (HBV) infection, but this association has dramatically changed in recent years due to declining HBV prevalence. Current epidemiological research often identifies a connection between PAN and genetic syndromes as well as neoplasia. This article provides a comprehensive review of PAN, specifically focusing on the progression of its clinical manifestations over time.