Rare Vasculitides: An Overview

Introduction

Vasculitides, a group of disorders characterized by inflammation of blood vessels, comprise a spectrum of diseases that can affect individuals of all ages. While some types of vasculitis are well-known and relatively common, there exists a subset of rare vasculitides that present unique challenges for both patients and healthcare providers. These uncommon conditions often demand heightened clinical awareness, thorough diagnostic evaluation, and specialized management approaches.

What Is Vasculitis?

Vasculitis is a condition causing inflammation and swelling in the blood vessels. These vessels, like highways in the body, include arteries (transporting blood away from the heart), veins (carrying blood back to the heart), and capillaries (small connectors between arteries and veins). When a person has vasculitis, the blood vessels become swollen and thicker, making it challenging for blood to flow correctly. This inflammation can, over time, harm the organs and lead to severe issues such as aneurysms. For many with vasculitis, symptom management is possible through medication. However, severe symptoms impacting blood flow to organs can be life-threatening.

What Are Some Rare Forms of Vasculitis?

• Polyarteritis: Macroscopic and Microscopic: Polyarteritis, encompassing macroscopic and microscopic forms, is a type of vasculitis, signifying inflammation in multiple arteries. Macroscopic polyarteritis involves visible inflammation in larger arteries, often impairing blood flow and organ damage. In contrast, microscopic polyarteritis affects smaller blood vessels, including capillaries. This form may manifest as microscopic polyangiitis (MPA) or polyarteritis nodosa (PAN). These conditions share common symptoms, such as fever, fatigue, and organ dysfunction. Distinguishing between macroscopic and microscopic polyarteritis is crucial for accurate diagnosis and tailored treatment. Early diagnosis is important to manage symptoms and prevent complications, underscoring the significance of prompt medical attention.

• Cutaneous Polyarteritis: This syndrome presents with painful skin nodules and a mottled, lace-like skin pattern known as livedo reticularis, often linked to a prior sore throat or ear infection. According to David et al., patients exhibit a reddish, nodular, and painful rash, primarily on the inner part of the foot, along with brief arthritis in the knees and ankles. Over half of the cases involve swollen muscles and puffiness around the eyes. Sometimes, systemic necrotizing vasculitis is risky, especially in recurring issues. Treatment typically includes Penicillin, NSAIDs, and steroids. For individuals with significant systemic involvement and compromised immune systems, additional therapy is necessary. Although most cases have a mild course, around 25 percent may experience relapses, particularly when associated with streptococcal infections. As a preventive measure, individuals should receive penicillin during childhood.

• Wegener’s Granulomatosis: Wegener’s granulomatosis is a rare inflammatory disease that affects the respiratory tract and sometimes the kidneys and small blood vessels. It can show up throughout the body or just in the respiratory system. Although uncommon, it has been seen in children. The symptoms are similar to another condition called polyarteritis nodosa and may include throat narrowing, sinus problems, and lung complications. Sometimes, it is confused with a condition called relapsing polychondritis. Kidney problems are not always present, and the diagnosis involves finding specific antibodies in the blood. Treatment, similar to another condition called polyarteritis, includes medications like steroids and antiplatelet drugs. Some people need ongoing treatment, and around 15 percent may face serious complications.

• Churg-Strauss Syndrome: Churg-Strauss syndrome, also known as allergic granulomatosis, is sporadic in children. It involves various inflammation-related issues in blood vessels connected with asthma and high levels of eosinophils (a type of white blood cell). Chest X-rays may reveal infiltrates, and biopsies may show features like tissue inflammation and granulomas. Specific antibodies can be found in the blood. Treatment typically involves steroids, and in some cases, medications like Cyclophosphamide may be added. It is crucial to address both the vasculitis and underlying conditions. While uncommon in kids, early diagnosis and appropriate therapy are essential for managing Churg-Strauss syndrome.

• Primary Angiitis of the Central Nervous System: Systemic vasculitis and secondary vasculitides linked to infection, drugs, and certain disorders can affect the central nervous system (CNS). Another form, known as primary angiitis of the CNS or primary granulomatous angiitis of the CNS, is typically found in adults but can also occur in childhood. This condition is increasingly recognized as a cause of unexplained cerebral ischemic episodes in young individuals. Symptoms include headaches, confusion, intellectual decline, and various neurological issues without the usual systemic features of vasculitis. Diagnostic tests often show abnormalities in small or medium-sized arteries. While the cause is unknown, treatment with steroids and Cyclophosphamide is recommended, although the prognosis remains challenging.

• Hypocomplementemic Urticarial Vasculitis: It is a type of vasculitis with noticeable symptoms like recurrent hives, swelling (angioedema), joint pain, arthritis, vomiting, and abdominal pain. It is associated with activating the classic complement pathway, leading to reduced levels of C3, C4, and Clq in the blood. In some cases, severe complications can arise, such as rapidly progressing kidney inflammation and lung bleeding. Treatment options include medications like Prednisolone and Hydroxychloroquine, but more potent immunosuppressive drugs may be necessary for aggressive forms of the disease. This condition requires careful management to address skin-related symptoms and potential systemic complications.

• Takayasu's Disease: It is a rare type of giant-cell arteritis that affects large muscular arteries, especially the aorta and its major branches, causing narrowing and sometimes bulging (aneurysms). While it is the third most common childhood vasculitis globally, it is relatively rare in Europe and North America. The exact cause is unclear, but there is a suggestion that tuberculosis may be involved. Early signs include fever, night sweats, loss of appetite, weight loss, and arthritis. As the disease progresses, high blood pressure, heart failure, and pulse deficits may occur. Diagnostic tests include Doppler ultrasound, magnetic resonance imaging, and angiography. Treatments vary, including steroids, Cyclophosphamide, Methotrexate, and sometimes anti-tuberculosis therapy. Managing blood pressure, angioplasty, and reconstructive vascular surgery are considered in the chronic phase. Significant health challenges can exist while long-term survival is high (around 90 percent).

• Miscellaneous Vasculitides: Several disorders have a vasculitic component, and three noteworthy ones are Behçet's syndrome, familial Mediterranean fever, and Cogan's syndrome.

1. Behçet's Syndrome: Although rare, Behçet's syndrome, marked by a significant vasculitic component, can affect children. Treatment involves steroids and cytotoxic drugs like Azathioprine or Cyclophosphamide. Colchicine, Levamisole, Cyclosporin A, and Thalidomide are additional options. Prognosis varies, with vascular involvement indicating a less favorable outcome.

2. Familial Mediterranean Fever: Linked to polyarteritis nodosa and Henoch-Schonlein purpura, familial Mediterranean fever may necessitate additional therapy, such as steroids for Henoch-Schonlein purpura or a combination of steroids and Cyclophosphamide for polyarteritis nodosa.

3. Cogan's Syndrome: A rare condition primarily affecting young adults, Cogan's syndrome can also occur in children. It involves non-syphilitic interstitial keratitis and vestibulo-auditory dysfunction associated with a vasculitic disease. Treatment often includes corticosteroids.

These disorders highlight the varied presentations of vasculitic conditions, requiring tailored therapeutic approaches based on the specific characteristics and complications involved.

Conclusion

Just like in adults, there's a broad range of vasculitic diseases that affect children. Common ones like Henoch-Schonlein purpura and Kawasaki disease are usually easily identifiable. However, the less common forms of vasculitis can present with less clear symptoms, making distinguishing from infections or other disorders challenging. Awareness of a vasculitic condition and current diagnostic tools can aid in reaching a diagnosis, even when shared features exist among different states. Early and appropriate treatment is crucial because without it, there's a high risk of mortality, and even with current therapies, there's still a significant impact on health. Therefore, clinicians need to consider vasculitis as a potential diagnosis, given its ability to mimic various other medical conditions in children.