PAN has mulitsystem involvement and progresses within few weeks to months [13]. It may affect a single organ or lead to visceral failure. Symptoms depend on the affected organs

• Musculoskeletal involvement – patients with musculoskeletal involvement present with common symptoms like fever, malaise, myalgia, arthralgia, anorexia, and weight loss
• Central nervous system involvement – when CNS is involved, temporary monocular blindness, cerebral ischemia, and subarachnoid hemorrhage may result. Lesions in CNS usually happen 2-3 years after the onset of PAN. Stroke, seizure, and focal deficits also present with CNS involvement. 
• Peripheral nervous system involvement – about 60% of the patients present peripheral neuropathy. Mononeuritis multiplex, distal polyneuropathy, and cutaneous neuropathy are also reported. 
• Skin involvement – this is one of the most common symptoms of PAN and is more common in legs. Rash, gangrene, cutaneous infarcts, nodules and livedo reticularis may be seen as manifestations of skin involvement. 
• Gastrointestinal involvement – most of the symptoms of GI involvement are nonspecific like abdominal pain, nausea and vomiting. In serious cases of PAN, pancreatic infarction, cholecystitis, and intestinal perforation may be noted. 
• Renal involvement – vasculitis of arteries in the kidney may result in renal failure and/or hypertension. Many patients complain of flank pain. 
• Other organ involvement – when other organs and organ systems like genitourinary system are affected, additional symptoms may be presented. Pain in testicular or ovarian area, chest pain, congestive heart failure, myocardial infarction, blurred vision, headache, psychosis and depression also may be seen depending on the organ affected. 

• Fever

  Interestingly, both had Mediterranean fever gene (MEFV) mutation, i.e. heterozygous E148Q. They also shared HLA-A24, -DR15 alleles. Simultaneous occurrence of MEFV mutation and HLA alleles with CPAN has never been reported in Japan. [ncbi.nlm.nih.gov]

  The first case of CPAN reported in the English-language literature may be that of a 7-year-old boy who, in 1870, died of "scarlet fever" at St. Bartholomew Hospital in London. [emedicine.com]

• Weight Loss

  Patients typically present with systemic symptoms such as fever, weight loss, and malaise. The kidneys, skin, joints, muscles, nerves, and gastrointestinal tract are commonly involved, usually in some combination. [ncbi.nlm.nih.gov]

• Weakness

  A 71-year-old man was hospitalized because of muscle weakness of the lower limbs that persisted for 1 month. On a physical examination, rapidly progressive lower proximal muscle weakness and bilateral drop foot were observed. [ncbi.nlm.nih.gov]

  Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness (peripheral neuropathy). [en.wikipedia.org]

  Symptoms include: Abdominal pain Decreased appetite Fatigue Fever Joint aches Muscle aches Unintentional weight loss Weakness If nerves are affected, you may have numbness, pain, burning, and weakness. [nlm.nih.gov]

  Myalgias, weakness or leg tenderness : diffuse myalgia (excluding shoulders and hip girdle) or weakness of muscles or tenderness of leg muscles. [rheumtutor.com]

• Fatigue

  Abdominal pain, fever, fatigue, and myalgia were the most frequent complaints. Doppler ultrasonography (US) was used in the diagnosis of seven patients and computed tomography (CT) angiography was done in four patients. [ncbi.nlm.nih.gov]

  Polyarteritis nodosa mnemonic It usually presents with vague symptoms like myalgias, arthralgias, abdominal pain, fatigue. Renal involvement manifests as hypertension, renal insufficiency. [medicowesome.com]

  Symptoms are fatigue, weakness, fever, abdominal pain, decreased appetite, unintentional weight loss and muscle and joint pain. [house.wikia.com]

  We ask about general symptoms (anxious mood, depressed mood, fatigue, pain, and stress) regardless of condition. Last updated: May 14, 2019 [patientslikeme.com]

  Fatigue, weight loss, and fever are common. Polyarteritis nodosa is often abbreviated PAN. What are causes and risk factors for polyarteritis nodosa? Polyarteritis nodosa is most common in middle-age people. [medicinenet.com]

• Malaise

  Patients typically present with systemic symptoms such as fever, weight loss, and malaise. The kidneys, skin, joints, muscles, nerves, and gastrointestinal tract are commonly involved, usually in some combination. [ncbi.nlm.nih.gov]

  His symptoms are associated with malaise, fever, and weight loss. He does not have a family history of malignancy and his last colonoscopy was unremarkable. His blood pressure is 155/98 mmHg (his blood pressure is usually 125/74 mmHg). [medbullets.com]

  Neurological – mononeuropathy multiplex Renal – renovascular hypertension, vascular nephropathy Pediatrics Epidemiology Age – peak is 9-11 years Sex – M Clinical Presentation Tends to be a more limited disorder than in adults Constitutional – fever, malaise [arupconsult.com]

  Nonspecific systemic signs and symptoms are almost always present and include fever, malaise and weight loss. Localized symptoms relate to ischemia and infarction of affected tissues and organs. [erj.ersjournals.com]

• Abdominal Pain

  Symptoms on admission included a generalised rash, colicky abdominal pain, hypertension, proteinuria and fresh rectal bleeding. Abdominal pain and distension worsened and serial ultrasounds suggested bowel ischaemia. [ncbi.nlm.nih.gov]

  Polyarteritis nodosa mnemonic It usually presents with vague symptoms like myalgias, arthralgias, abdominal pain, fatigue. Renal involvement manifests as hypertension, renal insufficiency. [medicowesome.com]

• Nausea

  There maybe nausea, vomiting and abdominal pain due to GI involvement (Untreated patients may die of bowel infarcts, perforations) Peripheral neuropathy, rash, purpura, CHF, CVA, etc are other manifestations of the disease. [medicowesome.com]

  […] levels of protein in the urine Numbness, tingling or weakness of the hands and feet Pain in the joints, especially the large ones Skin rash with raised reddish-purple patches and knobs that can be felt along affected arteries Stomach pain sometimes with nausea [cedars-sinai.edu]

  Skin: Rashes Open sores Small bumps under the skin Bruises Death of skin tissue Nervous system: Tingling, burning, pain, or numbness in your feet, hands, legs, arms, and face Decreased alertness Inability to think clearly Gastrointestinal: Belly pain Nausea [cancercarewny.com]

  Gastrointestinal tract: may cause sysmptoms such as abdominal pain, nausea and vomiting, bleeding, bowel perforation. Skin: About 40% of patients develop a rash, bruising, nodules and Raynaud phenomenon. [myvmc.com]

  Kidney failure does not give rise to early symptoms but over time swelling and nausea may develop, and the quantity of urine diminishes. The gastrointestinal tract is usually affected causing abdominal pain, nausea and vomiting. [socialstyrelsen.se]

• Loss of Appetite

  They can include skin rashes and ulcers, muscle and joint aches, fever, fatigue, weakness, abdominal pain, and loss of appetite. Nerve pain and numbness also can be associated with PAN. [kidshealth.org]

  Patients who have PAN may feel generally ill and fatigued, have fevers, or have loss of appetite and weight. [my.clevelandclinic.org]

  Constitutional symptoms are seen in up to 90% of affected individuals and include fever, fatigue, weakness, loss of appetite, and unintentional weight loss. Muscle and joint aches are common. [en.wikipedia.org]

• Acute Abdomen

  Here we report a case of a young Chinese patient who presented with an acute abdomen requiring surgery and made good recovery post operatively. He remains free of symptoms while on steroid therapy. [ncbi.nlm.nih.gov]

  A localized type of PN in the gallbladder has been rarely reported with or without signs of autoimmune diseases or acute abdomen [ 8 - 12 ]. [alliedacademies.org]

  Perforation of the gallbladder with acute abdomen may occur. Vasculitis of medium-sized mesenteric arteries causes abdominal pain, nausea, vomiting (with or without bloody diarrhea), malabsorption, intestinal perforation, and acute abdomen. [msdmanuals.com]

  abdomen is associated with a 50 percent mortality rate. 1 Prompt treatment with corticosteroids and cyclophosphamide improves 5- year survival to 80 percent, 5 making early recognition paramount. [appliedradiology.com]

• Intestinal Perforation

  Vasculitis of medium-sized mesenteric arteries causes abdominal pain, nausea, vomiting (with or without bloody diarrhea), malabsorption, intestinal perforation, and acute abdomen. Aneurysms may develop in hepatic or celiac arteries. [msdmanuals.com]

  Mona Mlika, Heifa Azouz, Inès Chelly, Sofiène Ayadi, Wael Rbai, Nidhameddine Kchir, Slim Haouet and Mohamed Moncef Zitouna, About a rare cause of intestinal perforation, Open Journal of Internal Medicine, 01, 02, (14), (2011). [doi.org]

  There was no evidence of intestinal perforation from the stomach to the sigmoid colon. After removing the rectal hematoma and necrotic tissue, a huge lack of rectal wall spreading to the pelvirectal space was observed (Fig. 2b ). [surgicalcasereports.springeropen.com]

  In serious cases of PAN, pancreatic infarction, cholecystitis, and intestinal perforation may be noted. Renal involvement – vasculitis of arteries in the kidney may result in renal failure and/or hypertension. Many patients complain of flank pain. [symptoma.com]

• Hypertension

  Classifying hypertension as ‘primary’ or ‘secondary’ depends on the underlying mechanism. [ncbi.nlm.nih.gov]

• Vascular Disease

  disease w polyarteritis Polyneuropathy in collagen vascular disease with polyarteritis Polyneuropathy in polyarteritis nodosa Clinical Information Form of necrotizing vasculitis involving small- and medium-sized arteries; signs and symptoms result from [icd9data.com]

  Obstructive intestinal symptoms are described but usually resolve with treatment of the underlying vascular disease. [ncbi.nlm.nih.gov]

  A dictionary of medical eponyms Related people Adolf Kussmaul Rudolf Robert Maier A narcotising vascular disease involving the small and medium sized muscular arteries. [whonamedit.com]

  Abstract Periarteritis nodosa is an obliterative, inflammatory, vascular disease involving the small arteries and arterioles. [annals.org]

• Tachycardia

  She was in septic shock with tachycardia, tachypnea, and hypotension. [surgicalcasereports.springeropen.com]

  Protein in urine Gastrointestinal System: GI bleeding Abdominal pain Nausea/vomiting Constipation Melena Hematochezia Possible hemmorrhage or perforation (rare) Musculoskeletal System: Arthralgia Myalgia Arthritis (less common) Cardiac System: Chest pain Tachycardia [physio-pedia.com]

• Hypotension

  She was in septic shock with tachycardia, tachypnea, and hypotension. [surgicalcasereports.springeropen.com]

• Myalgia

  It is limited to the skin and has a recurrent and chronic course, possibly associated with fever, arthralgia, myalgia and neuropathy, but without visceral involvement. [ncbi.nlm.nih.gov]

• Arthralgia

  It is limited to the skin and has a recurrent and chronic course, possibly associated with fever, arthralgia, myalgia and neuropathy, but without visceral involvement. [ncbi.nlm.nih.gov]

• Purpura

  Small-vessel vasculitis includes Wegener granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis (microscopic polyarteritis), Henoch-Schönlein purpura, essential cryoglobulinemic purpura, and cutaneous leukocytoclastic angiitis. [emedicine.com]

  PANpable: Palpable purpura is seen in PAN. That's all! -IkaN [medicowesome.com]

  Abstract We describe the case of a previously healthy 12-year-old boy admitted to a tertiary paediatric centre with the clinical diagnosis of Henoch-Schonlein purpura (HSP). [ncbi.nlm.nih.gov]

• Palpable Purpura

  Feels like there is an outbreak of vasculitis recently at the SFVA with a few morning reports on palpable purpura and it’s characteristic finding on pathology: leukocytoclastic vasculitis (LCV)! [ucsfmed.wordpress.com]

  PANpable: Palpable purpura is seen in PAN. That's all! -IkaN [medicowesome.com]

  Livedo vascular pattern typical of cutaneous polyarteritis nodosa Expected results of diagnostic studies In the case of palpable purpura the cutaneous biopsy will show leukocytoclastic vasculitis. [dermatologyadvisor.com]

  Microscopic polyangiitis commonly manifests with palpable purpura, alveolar hemorrhage, symptomatic cardiac involvement but is less likely to have hypertension, neuropathy, or hepatitis B. [rheumaknowledgy.com]

  Skin manifestations of PAN include palpable purpura and livedo reticularis in some individuals. Abdominal pain may also be seen. Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness (peripheral neuropathy). [en.wikipedia.org]

• Skin Ulcer

  Other features include livedo reticularis, skin ulcers and tender indurated plaques. We report a 51-year old woman with a primarily livedo reticularis presentation of cutaneous polyarteritis nodosa without a nodular component. [ncbi.nlm.nih.gov]

  Cutaneous: Livedo reticularis, skin ulcers, tender erythematous nodules, bullous or vesicular eruptions, infarction and gangrene of fingers or toes, or a combination may occur. [msdmanuals.com]

  ulcers livedo reticularis purpura renal glomerulonephritis hematuria new onset hypertension pulmonary typically spares lungs, though may involve bronchial arteries gastrointestinal abdominal pain rectal bleeding Imaging Angiography indication considered [medbullets.com]

  Case 7-2007: a 59 year-old woman with diabetic renal disease and nonhealing skin ulcers. N Engl J Med. 2007; 356:1049–57 PubMed CrossRef Google Scholar Callen JP. Livedoid vasculopathy: what it is and how the patient should be evaluated and treated. [link.springer.com]

• Cutaneous Manifestation

  The most frequent cutaneous manifestations were ulcers, livedo racemosa, subcutaneous nodules, atrophie blanche lesions and purpuras; with lower limb involvement in all cases, however other areas were also involved. [ncbi.nlm.nih.gov]

  Francois Chasset and Camille Francès, Cutaneous Manifestations of Medium- and Large-Vessel Vasculitis, Clinical Reviews in Allergy & Immunology, 10.1007/s12016-017-8612-9, (2017). [doi.org]

  Although it is distinct from systemic polyarteritris nodosa in that it lacks significant internal organ involvement, extra-cutaneous manifestations may be evident. [bjmp.org]

  “Comparison of cutaneous manifestations in systemic polyarteritis nodosa and microscopic polyangiitis”. Br J Dermatol. vol. 159. 2008. pp. 615-620. [dermatologyadvisor.com]

• Skin Rash

  A 22 year old female presented with vasculitic skin rash. She was incidentally found to be hypertensive and had proteinuria. Skin biopsy showed leuco-cytoclastic vasculitis. [ncbi.nlm.nih.gov]

  Table: Common symptoms in children and adults with PAN according to frequency Symptoms Adults Children Most Frequent Nerve involvement Skin –rashes, nodules, ulcers Skin –rashes, nodules, ulcers, muscle aches, weight loss Fever, joint pains, muscle aches [vasculitis.org.uk]

  They can include skin rashes and ulcers, muscle and joint aches, fever, fatigue, weakness, abdominal pain, and loss of appetite. Nerve pain and numbness also can be associated with PAN. [kidshealth.org]

  The most common symptoms are: Blood in the urine Fever High blood pressure High levels of protein in the urine Numbness, tingling or weakness of the hands and feet Pain in the joints, especially the large ones Skin rash with raised reddish-purple patches [cedars-sinai.edu]

• Kidney Failure

  Two thirds of patients die of kidney failure and many succumb to bowel problems and additional complicating infection. [netdoctor.co.uk]

  Serious complications can include strokes, seizures, and kidney failure. Keep in Mind While polyarteritis nodosa can be serious, many people with the condition do very well. [kidshealth.org]

  Nervous system:Decreased alertness Peripheral neuropathy Muscle pain, numbness or tingling Tingling, numbness and pain in feet, legs, hands and arms Seizures Slurred speech Kidneys: Fluid retention Hypertension Kidney failure Skin: Hives Nodules Rashes [foundationforpn.org]

  Possible Complications Heart attack Intestinal necrosis and perforation Kidney failure Stroke When to Contact a Medical Professional Call your health care provider if you develop symptoms of this disorder. [nicklauschildrens.org]

• Hematuria

  Herein, we describe a patient who was initially diagnosed with lupus nephritis based on her clinical presentation, proteinuria, hematuria, positive anti-nuclear antibody, and a kidney biopsy. [ncbi.nlm.nih.gov]

  Unexplained systemic illness with multiple system involvement (renal, neurologic, dermatologic) Laboratory Testing Nonspecific testing – helpful in excluding other diagnoses or identifying organ dysfunction CBC – rule out infection Urinalysis (UA) – hematuria [arupconsult.com]

  […] adult males Spares the arterioles, capillaries, venules and glomeruli Associated with hepatitis B antigenemia Signs and symptoms Abdominal pain Systemic hypertension Anorexia and weight loss Abdominal distention Hematemesis, melena Jaundice Painless hematuria [learningradiology.com]

  Leukocytosis up to 20,000 to 40,000/microL (20 to 40 10 9 /L), proteinuria, and microscopic hematuria are the most common abnormalities. [msdmanuals.com]

• Oliguria

  Renal: If small- and medium-sized arteries in the kidneys are affected, patients may have hypertension, oliguria, uremia, and a nonspecific urinary sediment with hematuria, proteinuria, and no cellular casts. Hypertension may worsen rapidly. [msdmanuals.com]

• Stroke

  This report shows that ischemic strokes may occur as a result of minocycline-induced vasculitis. [ncbi.nlm.nih.gov]

  Death is often a consequence of kidney failure, myocardial infarction, or stroke. PAN may affect nearly every organ system and thus it can present with a broad array of signs and symptoms. [en.wikipedia.org]

• Seizure

  CASE PRESENTATION: A 26-year-old South-Asian female presented with left sided focal seizures with secondary generalization and visual disturbance for 2 days duration. [ncbi.nlm.nih.gov]

  Damage to the nervous system may cause strokes or seizures. No specific lab tests are available to diagnose polyarteritis nodosa. There are a number of disorders that have features similar to polyarthritis nodosa. These are known as "mimics." [nlm.nih.gov]

  Serious complications can include strokes, seizures, and kidney failure. Keep in Mind While polyarteritis nodosa can be serious, many people with the condition do very well. [kidshealth.org]

  Nervous system:Decreased alertness Peripheral neuropathy Muscle pain, numbness or tingling Tingling, numbness and pain in feet, legs, hands and arms Seizures Slurred speech Kidneys: Fluid retention Hypertension Kidney failure Skin: Hives Nodules Rashes [foundationforpn.org]

• Peripheral Neuropathy

  There maybe nausea, vomiting and abdominal pain due to GI involvement (Untreated patients may die of bowel infarcts, perforations) Peripheral neuropathy, rash, purpura, CHF, CVA, etc are other manifestations of the disease. [medicowesome.com]

  neuropathy Tender subcutaneous nodules Gangrene of fingers and toes Kidney (most frequently affected): 85% Multiple intrarenal aneurysms Multiple aneurysms of renal vessels in Polyarteritis Aneurysms may thrombose and disappear Appear in new locations [learningradiology.com]

  The patient should also be monitored for: Headache Dementia Psychosis Encephalopathy Cerebrovascular events Peripheral neuropathy Prognosis Almost half will die within three months of diagnosis if untreated, usually secondary to chronic kidney disease [patient.info]

  Nervous system:Decreased alertness Peripheral neuropathy Muscle pain, numbness or tingling Tingling, numbness and pain in feet, legs, hands and arms Seizures Slurred speech Kidneys: Fluid retention Hypertension Kidney failure Skin: Hives Nodules Rashes [foundationforpn.org]

  Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness (peripheral neuropathy). [en.wikipedia.org]

• Tingling

  Nervous system:Decreased alertness Peripheral neuropathy Muscle pain, numbness or tingling Tingling, numbness and pain in feet, legs, hands and arms Seizures Slurred speech Kidneys: Fluid retention Hypertension Kidney failure Skin: Hives Nodules Rashes [foundationforpn.org]

  The most common symptoms are: Blood in the urine Fever High blood pressure High levels of protein in the urine Numbness, tingling or weakness of the hands and feet Pain in the joints, especially the large ones Skin rash with raised reddish-purple patches [cedars-sinai.edu]

  Common problems include: General: Fever Weight loss Joint and muscle pain Skin: Rashes Open sores Small bumps under the skin Bruises Death of skin tissue Nervous system: Tingling, burning, pain, or numbness in your feet, hands, legs, arms, and face Decreased [cancercarewny.com]

  If the peripheral nerves are affected, patients may notice muscle weakness, tingling sensations or burning- or electric shock-type pains in the hands and/or feet. [therapeutique-dermatologique.org]

  Symptoms include persistent numbness, tingling or pain in the feet and/or hands, often combined with reduced muscle strength. The nerve controlling the muscles which lift the foot may be damaged (the peroneus nerve) resulting in foot drop. [socialstyrelsen.se]

• Headache

  Seven years later the left unruptured aneurysm enlarged, causing a sudden severe headache and a cavernous sinus syndrome. [ncbi.nlm.nih.gov]

  Some authors state that the incidence is falling, others that it is rising but this may be due to increased recognition. [ 8 ] Presentation Diagnosis is not easy, as PAN often presents in a vague manner with symptoms including fever, weight loss, headache [patient.info]

  Neurologic manifestations resolved with treatment including corticosteroids and cyclophosphamide; however, persistent fevers, rash, and headaches interfered with attempts at a corticosteroid taper. [pediatrics.aappublications.org]

  The commonest symptoms can be fever, weight loss, abdominal pain, high blood pressure ( hypertension ), heart trouble, nerve pain (neuralgia) and numbness in the limbs, inflamed joints, muscle pain, headaches, kidney failure and even bleeding from the [netdoctor.co.uk]

PAN is an uncommon disease with many clinical manifestations that make diagnosis difficult. Many diseases that affect the vascular integrity or result in vascular occlusion may present PAN-like symptoms. Certain drugs are also known to cause manifestations similar to that of vasculitis. Thus, it is important to distinguish the different causes for better treatment and prognosis.
Among the different imaging techniques for diagnosis, angiography is suggested when the affected tissue is inaccessible. This is preferred for aneurysms and stenosis in medium-sized blood vessels. It is also useful in case of gastrointestinal involvement, particularly when liver and kidney functions are affected. Microaneurysms in small arteries can be revealed using arteriograms. CT scan and MRI are other imaging methods that are used to check varied manifestations of PAN. These imaging techniques may be used in case of nonspecific presentations like thickening in the wall of intestine, obstruction in bowel movement, and thickening of mucosal folds. MRI is also suggested in CNS involvement where intracranial hemorrhage is suspected. Electromyography facilitates the detection of peripheral neuropathy, one of the most common complication associated with PAN.
When the affected tissue is accessible, biopsy is recommended. This includes skin, skeletal muscle and testes. Biopsy of muscles and arteries enables identification of inflammation. Histology of the affected tissue will show the presence of cellular infiltration within the wall of the vessel. In nerve cells, axonal degeneration is seen with loss of fibrous tissue. Laboratory studies are helpful in finding the systemic nature of PAN. Some of the common finding include elevated ESR, hepatitis B surface antigen, leukocytosis, proteinuria, elevated levels of liver enzymes and hypergammaglobulinemia. HBV-related PAN have increased levels of cryoglobulins.
Thus for a definitive diagnosis of the condition there should be one of the following findings: 1) histological proof of vasculitis, 2) positive serology of anti-neutrophil cytoplasmic antibodies (ANCA), 3) angiography or biopsy findings suggestive of vasculitis, and 4) elevated ESR [14].

• Pericardial Effusion

  effusion Pleural effusion Discoid atelectasis Nodules which may cavitate Patchy consolidation Liver: affected 66% of cases Treatment Corticosteroids 50% 5 year survival Bockus, Henry L. [learningradiology.com]

• Thrombocytosis

  Diagnostic Testing: Nonspecific inflammatory markers include elevated ESR or CRP, leukocytosis, anemia of chronic disease, and thrombocytosis. [rheumaknowledgy.com]

  Patients may have thrombocytosis, markedly elevated ESR, anemia caused by blood loss or renal failure, hypoalbuminemia, and elevated serum immunoglobulins. AST and ALT are often mildly elevated. Testing for hepatitis B and C should be done. [msdmanuals.com]

  Patients may have thrombocytosis, markedly elevated erythrocyte sedimentation rate, anemia caused by blood loss or renal failure, hypoalbuminemia, and elevated serum immunoglobulins. [merckmanuals.com]

• Eosinophils Increased

  Eosinophils increased focally in some parts of the arteries. Among the infiltrating lymphocytes, CD8 were more predominant than CD4, and they had infiltrated all the arterial walls ( Fig. 4D ). [alliedacademies.org]

• Leukocytes Increased

  Despite ongoing methotrexate treatment, the number of leukocytes increased after 18 months and was accompanied by worsening of the clinical picture ( Figure 2 ). [doi.org]

The main component of treatment for PAN is corticosteroids. If any of the major organs are involved or if the patient is steroid refractory, cyclophosphamide is also added to the treatment. The normal course suggested is high-dose of oral prednisone at 1mg/kg/day. Once the symptoms improve and ESR normalize, prednisone dose can be lowered gradually over a period of time. Those who are receiving steroid treatment for a long-term should be given calcium and vitamin D supplementation to overcome the risk of osteoporosis.
For those with HBV-related PAN, corticosteroids are recommended with antivirals and plasmapheresis. Antiviral medication is started after steroid withdrawal. Along with antivirals, plasma exchange is recommended 3 times a week for 3 weeks. This is gradually reduced and can be stopped once seroconversion occurs. The same treatment modality is being followed for PAN related to HCV infection. For cutaneous involvement in PAN, agents like NSAIDs, colchicine, and dapone are used. In severe cases of skin involvement, steroids and additional cyclophosphamide are recommended. Those with PAN induced by streptococcal infection, penicillin is recommended. These patients may need long-tern prophylaxis and this is particularly true of children. Further consultations depend on the organ affected.
Patients with PAN should be monitored carefully to look out for relapse or symptoms of a new organ being affected. Dosage of cyclophosphamide should be adjusted based on immunosuppression.

Prognosis of PAN is related to the amount of damage to the organs. The chances of mortality increases with factors including renal insufficiency, proteinuria, gastrointestinal complications, cardiomyopathy, and involvement of central nervous system [11]. A prospective study on 342 patients showed that when none of the factors are present, the mortality rate is 11.9% in five years. If left untreated, the survival rate in 5 years is 13%. But treatment with corticosteroids may improve the survival rate which might go up to 50-60%. In general, relapse of PAN is rare. Worst prognosis is seen in the case of central nervous system involvement [12]. Those who have abdominal syndromes tend to have poor prognosis. If there is no systemic involvement, the outcome is better. It is uncommon for patients to have permanent morbidity. Death occurs with untreated and serious vasculitis, as a result of complications that arise from immunosuppression, myocardial infarction and stroke.

The actual cause of PAN is still elusive. There are some cases in which infections, particularly viral, are involved in the development of this condition. There is a strong relationship between hepatitis B infection and development of PAN. It was one of the most common causes of this condition. Vasculitis may occur at any stage but is usually seen within 6 months of HBV infection, irrespective of its course [4]. PAN linked to hepatitis infection is induced by immune complex. As the use of hepatitis vaccines increased, the incidence of HBV-related PAN decreased considerably.
Although it is not a very important etiological factor, hepatitis C infection is also found to be related to PAN in some cases. Other viral infections including HIV, herpes zoster, and herpesvirus 68 are possibly involved in the development of this vasculitis. PAN is also known to be associated with some cancers, rheumatic diseases and blood diseases. There is an increased association of PAN with rheumatoid arthritis. Group A streptococcal infections are known to cause a flare-up of this disease, particularly in children. Many other infectious organisms cause PAN-like diseases which include the species of Klebsiella, Pseudomonas, and Yersinia [5]. Exposure to Isotretinoin is reported to be related to the occurrence of vasculitis [6]. PAN is also found to occur at an increased frequency with ulcerative colitis which is probably due to exposure to immune complexes or altered permeability of the gut. A study reports increased incidence of this vasculitis with familial Mediterranean fever [7].

Reports of incidence of this disease varies in different countries. It is relatively uncommon, with about 1.6 cases in a million in Sweden. In England the estimated incidence rate is 4.6 cases in one million, while in U.S it is 3-4.5 cases in comparable populations. Among adults, about 30.7 cases in a million are reported in Paris [8]. It occurs in all age groups, from children to adults. The incidence of PAN is more among 10 year old children, while among adults the most commonly affected age group is 40 to 65 years [9]. All ethnic groups are affected by this condition but is more prevalent in regions where hepatitis B infection is endemic. Studies report that PAN is found to be more prevalent among men when compared to women.

Vascular lesions characteristic of PAN are more commonly found in the bifurcation point and branching regions of arteries. Inflammation affects the entire wall with the laminae often destroyed and replaced with a fibrin-like, amorphous eosinophilic material. Inflammation of the vessel wall is characterized by necrosis of media with cellular infiltration, particularly by neutrophils, lymphocytes and eosinophils. Aneurysms and thrombi may occur at the site of lesion as walls are weak. Aneurysms may lead to hemorrhage. With the progression of lesions on vessels, intimal may proliferate into the lesion leading to ischemia or infarction [10]. Necrotizing vasculitis may co-exist with a healed lesion in different tissues. This co-existence may also be noted in different parts of the same tissue. Lesions are found in medium-sized arteries and are rare in large and small blood vessels.

A definitive method to prevent PAN is not known yet. Prompt treatment and close monitoring are the best ways to avoid complications and help remission.

Polyarteritis nodosa or PAN, is a rare form of vasculitis that affects small and medium-sized arteries. Inflammation of the blood vessels may affect skin and many other organs including kidney, gut and nerves [1]. This condition, first described by Kussumaul and Maier, may develop in any age group. It is found to occur in association with infections like hepatitis B and streptococcal infections [2]. If the condition affects internal organs significantly, it may be life threatening and immunosuppression may be needed. Cases where inflammation is restricted to skin are mild and need only minimal therapy. Based on the size of the blood vessel affected, PAN is subdivided into two groups: 1) Classical PAN, when it affects medium-sized blood vessels and 2) Microscopic polyangiitis, when inflammation affects the small-sized vessels [3]. PAN is a progressive disease and may be sub-acute, acute or chronic.

Polyarteritis nodosa or PAN is a rare form of autoimmune disease characterized by inflammation of small and medium-sized arteries. Inflammation of the blood vessels may affect different organs including intestine, heart, kidney and nerves, and may be life threatening in certain cases. It is found to occur in all age groups but it is more common among men than in women. The actual cause of PAN is not yet known. It may occur as a part of many viral and bacterial infections, malignancies and other diseases. It is more commonly seen in people with hepatitis B infection.
Since many organs are affected by the condition, a variety of symptoms may be presented in PAN. Some of the common nonspecific symptoms include fever, muscle pain, tiredness, and loss of appetite. Symptom depend on the organ affected. Skin sores, ulcers, and nodules are seen when skin is affected. When the condition affects gastrointestinal tract, abdominal pain and blood in stools are common symptoms. Shortness of breath and chest pain is common when inflammation affects heart. Inflammation of arteries in kidneys may cause high blood pressure. When nerves are affected, it may result in stroke, seizure, and loss of strength.
A variety of sources are used for definitive diagnosis of PAN. A complete medical history helps in checking for presence of symptoms of PAN. Physical examination helps to identify the organ affected by the disease, and also to rule out the possibility of other diseases that mimic symptoms of PAN. Blood tests are also used to identify the affected organ or site of inflammation. Imaging techniques like CT scan and MRI are useful in identifying the site of vasculitis. A definitive diagnosis can be done with angiogram and biopsy of affected tissue sample.
The cornerstone for the treatment of PAN is corticosteroids and medications that suppress immune system. This helps to improve the symptoms caused by inflammation of the blood vessel. Once the symptoms improve, dosage of corticosteroids can be reduced gradually and then stopped completely. The treatment duration and dose varies with the severity of the condition. PAN related to hepatitis and other infections are treated similarly but with an addition of antiviral medications. Outcome of this condition depends on the severity and the organ involved. But studies show that over 80% of the people survive the effects of PAN with early treatment. Prompt treatment and close monitoring help in remission.

1. Pettigrew HD, Teuber SS, Gershwin ME. Polyarteritis nodosa. Compr Ther. 2007; 33(3): 144-9.
2. Duffy J, Lidsky MD, Sharp JT, et al. Polyarthritis, polyarteritis and hepatitis B. Medicine. 1976; 55: 19-37.
3. Jennette JC, Falk RJ, Andrassy K, et al. Nomenclature of systemic vasculitides. Proposal of an international consensus. Arthritis Rheum. 1994; 37(2): 187-92.
4. Trepo C, Guillevin L. Polyarteritis nodosa and extrahepatic manifestations of HBV infection: the case against autoimmune intervention in pathogenesis. J Autoimmun. 2001; 16(3): 269-74.
5. Somer T, Finegold SM. Vasculitides associated with infections, immunization, and antimicrobial drugs. Clin Infect Dis. 1995; 20(4): 1010-36.
6. Chochrad D, Langhendries JP, Stolear JC, Godin J. Isotretinoin-induced vasculitis imitating polyarteritis nodosa, with perinuclear antineutrophil cytoplasmic antibody in titres correlated with clinical symptoms. Revue Du Rhumatisme. 1997; 64: 129-31. 
7. Ozen S, Saatci U, Balkanci F, Besbas N, Bakkaloglu A, Tacal T. Familial Mediterranean fever and polyarterits nodosa. Scandinavian J Rheu. 1992; 21: 312-13. 
8. Mahr A, Guillevin L, Poissonnet M, Aymé S. Prevalences of polyarteritis nodosa, microscopic polyangiitis, Wegener's granulomatosis, and Churg-Strauss syndrome in a French urban multiethnic population in 2000: a capture-recapture estimate. Arthritis Rheum. 2004; 51(1): 92-9.
9. Ozen S. Juvenile polyarteritis: is it a different disease? J Rheumatol. 2004 ;31(4): 831-2.
10. Colmegna I, Maldonado-Cocco JA. Polyarteritis nodosa revisited. Curr Rheumatol Rep. 2005; 7(4): 288-96. 
11. Guillevin L, Lhote F, Gayraud M, Cohen P, Jarrousse B, Lortholary O. Prognostic factors in polyarteritis nodosa and Churg-Strauss syndrome. A prospective study in 342 patients. Medicine (Baltimore). 1996; 75(1): 17-28.
12. Hughes LB, Bridges SL Jr. Polyarteritis nodosa and microscopic polyangiitis: etiologic and diagnostic considerations. Curr Rheumatol Rep. 2002; 4(1): 75-82.
13. Stone JH. Polyarteritis nodosa. JAMA. Oct 2 2002;288(13):1632-9.
14. Kallenberg CG. The last classification of vasculitis. Clin Rev Allergy Immunol. 2008; 35(1-2): 5-10.