Giant Cell Arteritis (GCA) is a rare condition that usually occurs in people above 50 years old. It is a type of blood vessel inflammation (vasculitis) that affects the medium and large arteries in the body. This inflammation can lead to narrowing, or blockage of the affected arteries, leading to reduced blood flow to the affected organs. GCA commonly affects the arteries in the head and neck leading to symptoms such as headaches and jaw pain while chewing on food. In severe cases, it may cause visual loss which may become permanent if treatment is not started promptly. Hence, GCA is considered a medical emergency.
What causes Giant Cell Arteritis?
The exact cause is not fully understood, but it is thought to result from an autoimmune response, where the body’s immune system mistakenly attacks its own blood vessels. This can be contributed by several factors.
•Genetic predisposition: it is more common in North European and Scandinavian countries, suggesting a possible genetic link. •Environmental triggers: infections or other environmental exposures may trigger or worsen disease in those who are genetically predisposed.
What are the symptoms of Giant Cell Arteritis?
Some common symptoms of GCA may include: •Fatigue •Persistent fever •Loss of appetite and/or weight •Headache, often around the temples •Scalp tenderness (e.g. pain when brushing hair) •Jaw pain while chewing (jaw claudication) •Sudden vision changes (e.g. blurred or double vision) or vision loss
Aches and stiffness around the shoulder and hip region may occur if patients have Polymyalgia Rheumatica , another inflammatory condition that is closely associated with GCA.
Not everyone will experience all of these symptoms as they vary depending on which arteries are affected and the severity of involvement. Signs and symptoms often develop gradually but may come on suddenly. Vision changes, in particular require urgent treatment to avoid permanent vision loss.
How is Giant Cell Arteritis diagnosed?
The diagnosis of GCA usually involves a combination of:
•Detailed medical history and physical examination, including assessment of the pulses and blood pressure •Blood tests including blood counts and inflammatory markers, such as the Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). •Ultrasound scan of the arteries located at the temples of the head and/or armpits (axilla) to look for inflammation •Imaging such as MRI, CT or PET scans, to look for inflammation of the large arteries like the aorta and its major branches •Taking a small sample (biopsy) of the artery located at the temple of the head (known as the superficial temporal artery) – the diagnosis of GCA is confirmed if the artery shows features of inflammation when viewed under a microscope.
What is the treatment for Giant Cell Arteritis?
GCA is a chronic condition that can be managed effectively with medications. The goal of treatment is to reduce inflammation, prevent damage to blood vessels, and preserve blood flow to vital organs. Treatment should be started immediately with high dose steroids if GCA is suspected to prevent serious complications such as vision loss.
Steroids are immune suppression medications that work quickly to reduce inflammation, often started at high doses and reduced over time. They are often given as high dose intravenous (injection through the veins) injections if there is concern of visual loss due to GCA, and then switched to oral steroids.
Treatment with other immune suppression medications is often required to reduce the long-term need for steroids and to further control the disease. Examples include: •Methotrexate (a weekly medication given as oral tablets of subcutaneous injections in the thighs or abdomen), azathioprine and leflunomide (both of which are daily oral medications) •Tocilizumab is a targeted biologic medication which is given as injections either intravenously (infusions given through the veins) on a monthly basis or subcutaneously (given as injections under the skin in the thighs or abdomen) on a weekly basis
Blood tests monitoring are usually required while on these medications.
Blood thinning medications (such as aspirin) and cholesterol lowering medications (such as statins) may be added to reduce the risk of stroke or vision loss, especially in patients with other medical conditions that increase the risk of these complications.
Your care will be managed holistically. As several organ systems may be affected in the same patient, patients with GCA are often managed by a team of medical professionals from different specialties, led by the rheumatologist. Your treatment plan will be coordinated and tailored to your symptoms and preferences. To prevent infections when on high doses of immune suppression medications, prophylactic antibiotics and certain vaccinations are encouraged (e.g. influenza, pneumococcal, COVID-19, respiratory syncytial virus and shingles). Other co-existing medical conditions such as osteoporosis, high cholesterol, diabetes mellitus and high blood pressure will also be addressed.
What should I do if I have Giant Cell Arteritis?
Patients with GCA are able to live active lives with the right treatment and support. Some recommended lifestyle changes include: •Eat a balanced diet. Avoid raw and partially cooked food to reduce risks of infections, especially if you are on medications that suppress the immune system (e.g. steroids). •Avoid smoking. •Stay active and exercise in moderation. Ensure sufficient rest and sleep well. •Attend regular medical check-ups to monitor your health. Participate actively in your care and ask questions during your clinic consultations. •Take your medications as prescribed, even when you feel well, to avoid disease flares. •Seek immediate medical attention if you develop changes in your vision, as this could suggest inflammation of the blood vessels in your eyes, which can lead to permanent vision loss if not addressed in a timely manner.
What should I do if I suspect I have Giant Cell Arteritis?
Seek a doctor's advice early. You will be referred to a specialist (rheumatologist) who can confirm the diagnosis and start you on the appropriate treatment. Once diagnosed, it is important to start treatment early and follow your rheumatologist’s advice. This condition is managed by the Division of Rheumatology and Allergy.
