With these symptoms differentials include

  1. Giant cell arteritis (GCA)
  2. Polymyalgia Rheumatica (PMR)

PMR similarly is an autoimmune disease that affects the elderly. Its hallmark symptoms include muscle pain and weakness affecting the large muscle groups especially in the hips and shoulders. Patients with PMR have trouble getting out of a chair and reaching for objects in cupboards. PMR symptoms also include low-grade fever, malaise, poor appetite, and weight loss. When symptoms affect the neck and higher, giant cell arteritis can be at work.

But with only these symptoms we can make a diagnosis of Temporal arteritis or Giant cell arteritis

Giant cell arteritis

Giant-cell arteritis (GCA) is a systemic autoimmune disease affecting primarily the elderly. Giant cell arteritis can cause sudden and potentially bilateral sequential vision loss in the elderly. Therefore, it is considered a medical emergency in ophthalmology and a significant cause of morbidity in an increasingly aging population. Although the temporal artery is most commonly involved, other arteries may certainly be affected. These include the aorta and the subclavian, iliac, ophthalmic, occipital, and vertebral arteries.Giant cell arteritis (GCA), also known as temporal or cranial or granulomatous arteritis, is a systemic autoimmune disease affecting primarily the elderly. It is characterized by granulomatous inflammation of the large and medium-sized arteries. GCA is most prevalent in the white population of European origin. There is an association with HLA-DR4 and HLA-DRB1 which suggests a genetic predisposition.Most patients affected are over the age of 60 years. The mean age is 70 years old. Women are affected more often.

Symptoms

The classic systemic symptoms of GCA include headache, scalp tenderness, and jaw claudication. Headache especially located at the temples is the most common symptom. Jaw claudication is the most specific symptom. It is important to remember that jaw claudication means pain with chewing. This symptom is not constant jaw pain. Patients develop a significant jaw ache while chewing, so they decrease their food intake and thereby lose weight and feel weak. A good way to ask about scalp tenderness is to ask whether combing or brushing the hair hurts the scalp. Infrequently, a patient may notice an inflamed artery on the scalp or temple and tell his or her doctor that it is tender leading to the diagnosis.

Visual symptoms

Sudden, severe, and sequential vision loss is the hallmark of giant cell arteritis. The vision loss is usually discovered upon awakening in the morning. Visual acuity is usually less than 20/200 in greater than 60% of patients who lose vision. The fellow eye usually gets involved within days to weeks of the initial eye. In addition to causing a sudden permanent vision loss, GCA can present weeks earlier with  a temporary loss of vision which is due to partial occlusion of the short posterior ciliary arteries or central retinal artery causing transient ischemia. GCA may initially also present with diplopia or eye pain.

Evaluation of patient

The American College of Rheumatology has developed a set of criteria for the diagnosis of temporal arteritis. Three of the five criteria must be present to make the diagnosis. These include:

  • Age greater than or equal to 50 at the onset of disease
  • New headache
  • Temporal artery abnormalities such as tenderness of the superficial artery or decreased pulsation
  • ESR greater than or equal to 50 mm/h
  • Abnormal artery biopsy including vasculitis, a predominance of mononuclear cell infiltration or granulomatous inflammation, or multinucleated giant cells.

Due to the patchy nature of the disease in the affected artery, a biopsy may yield a false negative if not taken of adequate length. The recommended length is at least 1 cm, with 1.5 cm to 3 cm showing a sensitivity of 85% to 90%, to achieve a successful biopsy. An elevated CRP, although not required for diagnosis, may also be helpful.

Lab Diagnosis

The two most important labs to order to help make the diagnosis of GCA are the Erythrocyte Sedimentation Rate (ESR) and the C – reactive protein (CRP). These two lab values, if elevated, indicate systemic inflammation. If either blood value is high, this may point you to a diagnosis of GCA, but one must remember that the ESR and/or CRP may be elevated from other causes of systemic inflammation like infection, malignancy, Diabetes, or other auto-immune diseases like Lupus or Rheumatoid arthritis. Top normal for ESR in men can be calculated by Age divided by 2, women (Age + 10) divided by 2. Thrombocytosis or increased platelets is also a sign of active inflammation in the body, so it is wise to order a complete blood count (CBC) at the same time as ESR and CRP to help cinch the diagnosis. Elevated platelet counts and CRP can be more sensitive inflammatory markers than ESR.

Treatment/Management

The management of a suspected GCA patient must be done quickly because there is a risk of permanent sequential vision loss (blindness) if treatment is delayed. This is why giant cell arteritis is the number one medico-legal entity in ophthalmology in the developed world. The physician must carefully review the three aspects of the patient’s clinical presentation: history, examination, and lab results. You suspect that the patient may have giant cell arteritis due to the history: he or she admits to headaches at the temples, scalp tenderness, neck pain, malaise, weight loss, low-grade fever, and/or jaw claudication. Your ophthalmic examination is consistent with GCA: Swollen or chalky white disk, CRAO, cotton wool spots in the retina, choroidal hypoperfusion on FA, and/or tender temporal artery. Lastly, stat ESR or CRP or both are elevated on the lab review.

A good rule of thumb is if 2 out of the 3 above parameters are positive, treatment and temporal artery biopsy must follow. The temporal artery biopsy is considered the gold standard in diagnosis. But do not wait for the results of the temporal artery biopsy before treating the patient. You must begin high-dose steroids immediately. Oral prednisone should be started at a dose of 1 milligram/kilogram per day. High-dose steroid therapy is usually effective in preventing further visual loss. A few eyes may demonstrate visual deterioration during the first 5 days of treatment, and, conversely, a few eyes may show a mild improvement in visual acuity with high-dose corticosteroids.

When the patient returns for the temporal artery biopsy, the physician should ask the patient whether the prednisone helped the GCA symptoms. If the classic GCA symptoms improved on prednisone, this would correlate well with the diagnosis of GCA. If the opposite is true, and the patient’s symptoms of headache, scalp tenderness, and jaw claudication did not improve with prednisone, this finding would go against the diagnosis of GCA, even before the biopsy was done. Then we go for biopsy.

Pathological findings

Histopathologically, two patterns are considered diagnostic of giant cell arteritis: those with inflammation of the vessel wall (active arteritis) and those with post-inflammatory alterations (healed arteritis). With active arteritis cellular infiltration of the artery wall is seen. The adventitia, media, and intima are thickened with a preponderance of lymphocytes, macrophages, and giant cells. It is important to remember that multi-nucleated giant cells which are a coalescence of macrophages do not have to be present in a positive temporal artery biopsy. The primary inciting cause of the inflammation is unknown but may be due to a bacterial or viral antigen. Healed arteritis lacks the active inflammation but will show fibrosis of the vessel wall with disruption of the internal elastic lamina. Elastin stains may be used to highlight a fragmented or disrupted internal elastic lamina. Positive biopsies, whether active or healed, are treated the same initially with high dose steroids.

 Conclusion

Giant cell arteritis is a systemic autoimmune disease of the elderly that has potentially devastating visual consequences. Early diagnosis and treatment are critical. Hope this article will help.