运动性低血糖：定义、症状与管理

Overview

Polyarteritis nodosa (PAN) is a rare autoimmune condition that causes inflammation of the walls of medium-sized arteries, a type of damage called vasculitis. This inflammation narrows or blocks arteries, reducing blood flow to tissues and organs, which can cause permanent damage. PAN most often affects the skin, kidneys, peripheral nerves (nerves in the hands and feet), and gastrointestinal tract, but can impact almost any organ. It is not contagious, and affects about 1 to 2 people per 100,000 in the United States, with higher rates in people assigned male at birth. Most people are diagnosed between the ages of 40 and 60.

Signs & Symptoms

Symptoms of PAN vary widely depending on which organs are affected, and often develop gradually over weeks or months. Common signs include:

• Skin changes: painful red or purple rashes, nodules, or livedo reticularis (a net-like purple pattern on the skin, usually on the legs)
• Peripheral neuropathy: numbness, tingling, burning, or weakness in the hands and feet
• Muscle and joint pain
• Abdominal pain, nausea, vomiting, or diarrhea (often after eating)
• Unexplained high blood pressure
• Kidney symptoms: blood in the urine, swelling in the legs or ankles
• Fever, unintended weight loss, and persistent fatigue
• Chest pain or shortness of breath (if the heart or lungs are affected)

Causes & Risk Factors

The exact cause of PAN is not fully understood, but it occurs when the immune system mistakenly attacks the walls of medium-sized arteries, triggering inflammation. In about 30% of cases, PAN is linked to hepatitis B virus (HBV) infection, which triggers the abnormal immune response. Less common risk factors include other viral infections, certain medications (rarely), and a family history of autoimmune conditions. Most people with PAN have no identifiable trigger.

Diagnosis

Diagnosing PAN can be difficult because its symptoms overlap with many other conditions. Your healthcare provider will start with a physical exam and review of your medical history, then order tests to confirm the diagnosis and assess organ damage:

• Blood tests: to check for markers of inflammation, hepatitis B status, kidney function, and nerve damage
• Imaging tests: angiograms, CT scans, or MRIs to look for narrowed, blocked, or aneurysmal (bulging) arteries
• Nerve conduction studies: if you have symptoms of peripheral neuropathy
• Tissue biopsy: the most definitive test, where a small sample of skin, muscle, or nerve tissue is examined for inflammation of the artery walls

Treatment & Management

There is no cure for PAN, but early and consistent treatment can control inflammation, prevent organ damage, and induce long-term remission. Treatment is tailored to the severity of your condition and which organs are affected:

Living With It

Long-term management of PAN focuses on preventing flare-ups, monitoring for organ damage, and maintaining your quality of life. Regular follow-up appointments with a rheumatologist (a doctor specializing in autoimmune and inflammatory conditions) are essential, along with routine blood and imaging tests to track your disease activity.