|
|
|
Giant Cell Arteritis is known by other names – Temporal Arteritis, Horton’s Disease, cranial arteritis and granulomatous arteritis. It is manifested by the presence of giant cells in the lining of the wall of a large or medium sized artery and is one of many vasculitic diseases. Giant Cell Arteritis (GCA) affects mainly people aged 50 or older, women more than men, and almost exclusively Caucasians. There are reports of giant cells being found in younger people – like a 17 year old boy and others in their 40s - but these appear to be very infrequent occurrences. Diagnosis is difficult in these rare situations because age greater than 50 years is one of the basic criteria used. People of Northern European extraction appear to be most susceptible – Scottish Irish, Scandinavians, Italians, Spanish, etc.
It can infiltrate large arteries anywhere in the body but is found most often in the cranium – the temporal artery and optic nerve artery – or in the aorta. The major concerns with GCA are permanent loss of vision or aneurysms in the aorta. Cases of inflammation occurring in leg or arm arteries are not uncommon – ovary artery involvement has been reported as well as arteries leading to the major organs and the spine.
The disease has been reported in medical journals since 1943 or earlier. Over 17 million abstracts of all types of medical articles are available on the Entrez PubMed website – www.pubmed.gov. The abstracts usually contain enough information that often there is not a need by the patient to obtain the full article.
Symptoms of GCA are not always present. Permanent blindness or sudden death is the initial and sole symptom for some unfortunate people. Most patients present with one or more symptoms which can include severe headache, vision disturbances, scalp tenderness, jaw claudication (difficulty chewing), ear or neck pain, sinus involvement, impaired circulation in any limb, chest discomfort, unexplained weight loss, aortic aneurysm, low grade fever or night sweats. Blood serum tests may show elevated C-reactive Protein (CrP), Erythrocyte Sedimentation Rate (sed rate), white blood cell count, alkaline phosphatase, or platelet count; or depressed red blood cell count, hemoglobin or hematocrit. The symptoms disappear within several days upon adequate administration of prednisone. If vision is lost in one eye prednisone therapy is urgently needed to protect the other eye – very few instances of regaining even partial vision have been reported once vision is lost. The cause of vision loss generally is constriction and interruption of blood flow in the artery supplying the optic nerve
The cause of GCA is not known – speculation includes genetic, viral or environmental factors as contributors. Cases of familial involvement – mother/daughter, three female siblings - have been reported but such occurrences are rare. Some studies have found a cyclic pattern of new GCA cases coincident with viral epidemics in some localized geographical areas. Mold in the patient’s environment has been suspected by some patients but I haven’t found evidence of mold being a factor in medical journals. Pearl had mold exposure in our home.
GCA may remain active for an indefinite period. Some cases resolve within a year, others never achieve remission. Published data generally describes it as a one to three years illness for most patients. Daily prednisone is the only effective medication for management of GCA. It is essential that prednisone be administered at once when a strong suspicion exists for GCA. A starting oral dose of 60 mg/day is commonly given to protect vision. 120 mg/day or IV dosing may be administered if vision is involved. Tapering is fairly rapid to a maintenance dose sufficient to keep arterial inflammation under control.
A temporal artery biopsy is needed to confirm the diagnosis of GCA. It is done on one side and, if giant cells are not found, it is repeated with surgical removal and biopsy of the other temporal artery. Biopsy confirmation is desirable to avoid long term high dose prednisone therapy if GCA isn’t present. GCA is managed by monthly blood tests of C-rP, sed rate, Complete Blood Count (CBC) and Comprehensive Metabolic Panel (CMP), in addition to watching for symptoms of flares of the disease.
Patients with GCA often have a companion disease - polymyalgia rheumatica (PMR). Some think GCA and PMR are the same disease, just at opposite ends of the full spectrum of symptoms for this form of vasculitis. PMR, like GCA, primarily affects older adults. It causes pain and inflammation of the large joints - shoulders, hips and knees. Signs and symptoms include pain and stiffness in the muscles of the hips, thighs, shoulders, upper arms and neck, elevated C-rP and sed rate, and duration of morning stiffness greater than 45 minutes. Confirmation of PMR is speculative. If it can’t be shown to be another illness and it responds to prednisone treatment of 20 mg/day it likely is PMR. Response is immediate – pain disappears within several days of prednisone administration.
Both GCA and PMR are usually managed by a rheumatologist, ophthalmologist or neurologist but are sometimes managed by other medical professionals who’ve had experience with GCA patients. The prednisone requirements to manage GCA exceed that needed for PMR, so PMR becomes a secondary issue when both are present in a patient. Years later, should GCA run its course, PMR may become the primary focus of inflammation management. PMR, like GCA, has an indefinite time to remission. It can remain active from a few months to five years or longer. It also is managed with the aid of periodic blood tests.