Ординатура / Офтальмология / Английские материалы / Clinical Medicine in Optometric Practice_Muchnick_2007

FIGURE 13-8 ■ Bullous vulgaris. (From Marx J, Hockberger R, Walls R: Rosen’s emergency medicine: concepts and clinical practice, ed 6, St Louis, 2006, Mosby.)

FIGURE 13-9 ■ Pemphigus vulgaris. (From Kumar V, Abbas AK, Fausto N, eds: Robbins and Cotran: pathologic basis of disease, ed 7, Philadelphia, 2005, Saunders.)

conjunctival blisters occurs within 1 week. Most patients demonstrate autoantibodies on serum testing. Although pemphigus vulgaris is a life-threatening condition, glucocorticoid therapy has reduced mortality rates to approximately 5%.

Cicatricial Pemphigoid

Cicatricial pemphigoid is a rare, blistering skin condition that can cause scarring of the mucosal membranes and epidermis. It commonly involves the mouth and eyes, and is a chronic and progressive disorder. As the conjunctivae become eroded, symblepharon may

FIGURE 13-10 ■ Bullous dermatosis in cicatricial pemphigoid. (From Bietta G: Eye involvement in skin diseases. In Mausolf FA, ed: The eye and systemic disease, St Louis, 1975, MosbyYear Book.)

FIGURE 13-11 ■ Cicatricial pemphigoid. Lower and upper lids to the cornea in cicatricial pemphigoid. (From Yanoff M: Ophthalmology, ed 2, St Louis, 2004, Mosby.)

FIGURE 13-12 ■ Mooren’s ulcer: Peripheral corneal melting syndrome

Type III Hypersensitivity:

Clinicopathologic Correlates

Erythema Multiforme

Also known as Stevens-Johnson Syndrome (SJS), erythema multiforme has many causes, including reactions to infection and medications. Most common in men younger than 30 years, the disease’s onset is heralded by fever, malaise, anorexia, headache, and nausea. This prodrome is followed by skin eruptions, most commonly on the soles of the feet and palms of the hand (Figure 13-13). The lesion is typically a “bulls-eye” lesion with a red center surrounded by a ring of normal tissue. Around this lesion is often another erythematous ring. The most common sites affected are the mucosal membranes of the nose, mouth, and eyes (Figure 13-14). The conjunctivitis is characterized by a pseudomembrane formation that forms rapidly. The conjunctiva forms blisters that break and scar, causing symblepharon, entropion, trichiasis, corneal scarring, and blind-

FIGURE 13-13 ■ Erythema multiforme. Note the red “bulls-eye” lesions with a surrounding pale white ring, typically found on the palms and soles. (From Goldman L, Ausiello D: Cecil textbook of medicine, ed 22, Philadelphia, 2004, Saunders.)

A

B

FIGURE 13-14 ■ Erythema multiforme: Acute phase of Stevens-Johnson syndrome. This child has the typical target shaped macular skin lesions. A, The head, with an associated blepharoconjunctivitis. B, The trunk. (From Yanoff M: Ophthalmology, ed 2, St Louis, 2004, Mosby.)

ness. Treatment includes identification and immediate withdrawal of the offending agent. Aggressive management of the dry eye complications of SJS is necessary to prevent corneal involvement.

Type IV Hypersensitivity: Clinicopathologic Correlates

These hypersensitivity reactions are initiated by monocytes and mediated by T cells and macrophages. These reactions are useful as a mechanism against fungi, parasites, mycobacteria, and intercellular pathogens. Unfortunately, they also mediate transplant rejection and tumor immunosuppression. The result of T-cell dysfunction, as in HIV/AIDS, causes proliferation of

opportunistic infections that result in undesirable consequences, including contact dermatitis (poison ivy), allograft rejection, granulomatous disease (sarcoidosis and Crohn’s disease), and other environmentally influenced and autoimmune reactions.

Phlyctenular Conjunctivitis

This condition, also known as phlyctenulosis, causes the deposition of immune complexes in the limbus, cornea, or conjunctiva. The cause is most likely bacterial immunogens, which are antigenic and cause a delayed hypersensitivity reaction. The most common bacterial antigen in the world is the tubercle bacillus, although other bacteria have been implicated in the disease. In fact, the most common phlyctenular-associated bacterial infection in the United States is Staphylococcus. The lesion is a raised nodule surrounded by perivascular inflammation that causes pain, tearing, and photophobia (Figure 13-15). The eye is often red and irritated. Slit-lamp biomicroscopy will reveal a small, elevated yellowish-gray nodule on the bulbar conjunctiva or corneal limbus. During a 2-week period, the nodule will form, ulcerate, and resolve with scarring of the cornea. Clinicians should evaluate all patients with phlyctenular keratoconjunctivitis for tuberculosis by first asking the patient about any recent bouts of coughing. Ancillary tests include a skin purified protein derivative (PPD) or Mantoux test to rule out TB. Once diagnosed, the underlying disease must be treated. Topical steroids are used to treat the phlyctenular conjunctivitis.

Corneal Graft Rejection

After penetrating keratoplasty for corneal transplantation, the host immune system may recognize the foreign antigen present in the donor cornea. The rejection reaction may occur in the stroma, epithelium, or endothelium. Rejection by the immune system may lead to graft

FIGURE 13-15 ■ Phlyctenular keratoconjunctivitis. Whitish, heaped-up areas along the limbus represent a sterile inflammation associated with a cell-mediated hypersensitivity response to an antigen.

failure. Most rejection occurs between 1 month and 1 year after the procedure. Symptoms include foreign body sensation (epithelial rejection) and decreased vision with redness (endothelial rejection). Slit-lamp biomicroscopy reveals conjunctival injection, vascularization of the host peripheral cornea, microcystic edema of the wound site, and bullae formation of the cornea. To control graft rejection, topical corticosteroids are used hourly at first. Massive rejection is an indication for oral steroid use. Topical cyclosporine A (Restasis) has beneficial effects without undesirable side effects.

AUTOIMMUNE COLLAGEN-VASCULAR DISEASE

The immune system must be able to recognize self from nonself, and most animals do not mount an immune response to host antigens. In this way, the immune system is tolerant of self-molecules. The breakdown of the basic mechanisms that control immune tolerance is known as autoimmunity. The resultant pathological disorders of autoimmunity are known as autoimmune diseases. The essential characteristic of autoimmune disease is the development of an immune response by the organism against host tissue. Autoimmunity can be idiopathic or can occur as a consequence of trauma, infection, or exposure to environmental antigens. For example, the activation of lymphocytes against host tissue may occur because of exposure to microbes in a process known as cross-reactivity.

Typical of autoimmune disease is the presence of pathological lesions that are disseminated throughout several organs and tissues. For example, systemic lupus erythematosus (SLE) manifests in the skin, joints, kidneys, and blood vessels.

As a group, collagen-vascular diseases are characterized by deposition of fibrin and diffuse inflammatory damage to connective tissue and the vascular system. In addition, some element of autoimmunity appears to play a role in these conditions. Collagenvascular diseases often affect connective tissue, or those elements of the body that include collagen and elastin. The term collagen-vascular disease is used extensively, but it poorly describes the nature of this diverse group of clinical entities. The following collagenvascular diseases represent the significant autoimmune disorders that affect the body and eye.

Collagen Vascular Diseases:

Clinicopathologic Correlates

Systemic Lupus Erythematosus

A disease of unknown etiology, SLE is characterized by pathogenic antibodies that attack cells and tissues throughout the body. Of all cases, 90% occur in women of child-bearing age, but individuals of all ages can

158 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

be affected. Multiple organ systems are involved as autoantibodies, including T and B lymphocytes and immune complexes, cause damage by direct binding to cell membranes. A genetic predisposition to the disease appears to exist, in which some environmental influence triggers the immune response.

The American Academy of Rheumatology has developed a set of diagnostic criteria by which the presence of SLE can be established (the patient must meet 4 of the 11 criteria). These criteria include anemia, pericarditis, diarrhea, cognitive dysfunction, vascular thrombosis, musculoskeletal arthralgias and myalgias, proteinuria that indicates glomerulonephritis, and a “butterfly” rash across the bridge of the nose (Figure 13-16).

Ocular signs of SLE include retinal vasculitis, conjunctivitis, episcleritis, keratitis sicca, and optic neuritis. The retinal vasculitis of SLE appears as sheathed, narrow retinal arterioles and white exudates adjacent to the retinal blood vessels. The vasculitis is potentially blinding and must be treated with aggressive immunosuppression.

Laboratory diagnosis of SLE is made by establishing the presence of antibodies. ANA is the best screening test for SLE, though it is not specific for the disease. Serum testing may confirm the presence of anemia, leucopenia and thrombocytopenia. A Westergren erythrocyte sedimentation rate correlates with the activity of SLE. Urinalysis can be performed to measure creatinine levels, and proteinuria will reflect active nephritis.

No cure exists for SLE and the management of the condition is both complex and frustrating. Control of acute flare-ups is a primary goal of SLE therapeusis,

FIGURE 13-16 ■ Systemic lupus erythematosus of the face. Note the reddish “butterfly” rash across the cheek. (From Behrman RE, Kliegman RM, Jenson HB: Nelson textbook of pediatrics, ed 17, Philadelphia, 2004, Saunders.)

and involves the use of NSAIDs in mild, nonlifethreatening episodes. These antiinflammatory medications will help control the potentially disabling pain and fatigue of the fever, arthralgias, arthritis, and myalgias. Systemic antimalarial medications may be used to control the SLE-associated skin lesions. High doses of glucocorticoids may be needed to control the lifethreatening complications of SLE.

Treatment of the ocular complications of SLE includes the maintenance of the ocular surface and stabilization of the tear film, and frequent eye examinations to monitor for signs of retinal vasculitis.

Rheumatoid Arthritis

This chronic multisystem disease is characterized by inflammatory synovitis, or swelling of the peripheral joints. Relentless progressive polyarthritis may eventually result in cartilage damage and subsequent joint destruction.

The etiology of rheumatoid arthritis (RA) is unknown, but it is theorized that an environmental influence, such as a bacterial infection, stimulates the production of immune products that respond to components of the joint. Another possibility is that deposition of infective products in the synovial tissues occurs, leading to chronic inflammation of the joint.

The earliest lesions to occur in RA appear to be microvascular damage and an increase in synovial cells, but the initial stimulation for this change is as yet unknown. T cells are found in the synoveal fluids as the joint becomes edematous. This rheumatoid synovial fluid is composed of secreted products of the activated inflammatory cells and accounts for many of the clinical manifestations of RA. Within this fluid, immune complexes activate, complement, and generate chemotactic factors. In addition, mast cells will produce histamine that facilitates inflammatory cell exudation into the synovial fluid. Hyperplasia of the cells that line the joint is present. These factors produce the clinical characteristics of RA including exacerbations, remissions, variability of presentation, and chronicity.

RA begins insidiously, with the earliest symptoms of fatigue, anorexia, and multijoint involvement. During weeks to months a symmetrical involvement of the hands, wrists, knees, and feet occurs. These joints become painful, tender, and swollen, and movement becomes difficult. Patients often complain of joint stiffness during periods of inactivity and in the morning after awakening. The joints are swollen with synovial fluid and feel warm to the touch. With chronic involvement the joints become permanently damaged and there are functional changes in the feet, hands, wrists and knees.

RA can also cause the formation of nodules on the skin and meninges. Vasculitis may occur in severe RA and are associated with high titers of circulating

rheumatoid factor. Other organ involvements include the lungs, heart, and eye (Figures 13-17 and 13-18).

Almost one fifth of all RA patients develop Sjögren’s syndrome and keratitis sicca. All RA patients should be followed up twice yearly for signs and symptoms of dry eye. Less than 1% of individuals with RA exhibit other ocular manifestations of the disease. Episcleritis and scleritis (Figure 13-19) are the most common ocular manifestations of RA, and the lesions resemble the granulomatous RA nodule.

Laboratory analysis helps confirm the diagnosis of RA by the use of rheumatoid factor (RF), which are autoantibodies reactive with IgG. The presence of RF is not specific for RA because it is found in the normal population, increases with age, and may be elevated in patients with SLE, Sjögren’s syndrome, liver disease, sarcoidosis, TB, and hepatitis. RF is a poor screening test for RA, but high titers of RF in patients with RA

FIGURE 13-17 ■ Scleromalacia perforans secondary to rheumatoid arthritis. Note the dark gray uvea protruding through the sclera surrounded by the deep scleral injection, indicating scleritis.

FIGURE 13-18 ■ Advanced scleromalacia perforans. Note dramatic protrusion of the uvea through a thinned-out sclera.

FIGURE 13-19 ■ Scleritis. Note the deep involvement of scleral vessels with reddish-blue conjunctival injection pattern.

indicates a prognosis of significant severity and a chronic course. Active RA elevates the erythrocyte sedimentation rate (ESR) and C-reactive protein in all cases and is prognostic for the course and severity of the disease. Radiographic analysis is helpful later in the disease, but the patterns of involvement are not diagnostic of RA.

Diagnosis of the disease is usually made by the presence of morning stiffness, symmetric arthritis of the hands or three or more joints, the presence of rheumatoid nodules, elevated RF and radiographic changes of the distal joints.

Therapy for RA aims to reduce inflammation, relieve pain, maintain the functioning of the joint, and control systemic involvement. NSAIDs and simple analgesics are used to control pain and inflammation of the joint. Methotrexate, gold compounds, D-penicillamine, the antimalarials, and sulfasalazine have all been shown to improve the course of RA. In addition, systemic steroids can provide symptomatic relief in low doses and prevent bone erosions. Immunosuppressive agents such as azathioprine and cyclosporine have been shown to be effective in the treatment of RA.

Sjögren’s Syndrome

This chronic, multisystem, slowly progressing, autoimmune disease primarily affects the eyes, mouth, and throat. A lymphocytic infiltration of the exocrine glands, Sjögren’s syndrome causes dry eyes, nose, and mouth. It affects mostly middle-aged women and can occur either in isolation or in association with systemic diseases such as RA. The disease is characterized by B-lymphocyte hyperreactivity and circulating autoantibodies. Lab testing of patients with Sjögren’s syndrome often reveals elevated RF and assorted antigens.

In general, lacrimal and salivary gland function are diminished, with consequential mucosal dryness. In the mouth and throat, atrophy of the tongue and reduced

160 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

salivary secretion are present. Patients will complain of difficulty swallowing food and speaking.

In the eyes, destruction of the corneal and bulbar conjunctival epithelium occurs, causing the symptoms of dry eye, including sandy, dry, or gritty ocular sensations. The conjunctiva becomes infected, with the development of keratitis sicca.

The symptoms associated with Sjögren’s syndrome are a result of generalized dryness, or xerostomia. Besides dry mouth and eyes, exocrine involvement of the respiratory tract results in dry nose, throat, and trachea. Nosebleeds are a common sign of respiratory tract involvement. In addition, a reduced exocrine secretion in the gastrointestinal tract can lead to gastritis and pancreatitis. It is not unusual for patients to also exhibit drying of the skin.

Late in the course of the disease, parotid gland enlargement and lymphadenopathy can occur as a manifestation of low-grade lymphoma.

The ocular involvement of Sjögren’s syndrome includes a reduced tear lake, punctuate epithelial keratopathy with staining, a reduced break-up time, and an associated blepharitis.

Sjögren’s syndrome is an incurable disease, and treatment is aimed at symptomatic relief and control of the xerostomia of the mucosal membranes. Topical cyclosporine A (Restasis) used several times daily will help reduce the effects of keratitis sicca. The use of oral flax seed oil and omega-3 fish oil capsules has been advocated in the relief of dry eye, but control studies on these over-the-counter supplements is lacking. Patients should be advised to practice appropriate dental hygiene to reduce the risk of dental caries and gingivitis caused by drying of the mouth. Oral pilocarpine (Salagen) appears to improve sicca manifestations. Stimulation of exocrine glands with the oral agent cevimeline (Evoxac) can help relieve the symptoms of keratitis sicca and dry mouth. Glucocorticoids and cyclophosphamide help to suppress the immune system in cases in which Sjögren’s syndrome involves the kidneys, lungs, and blood vessels.

Scleroderma

In scleroderma (SCC), an overproduction of collagen occurs that tends to accumulate throughout the body. The earliest involvement is the small arteries, arterioles, and capillaries of the skin, gastrointestinal (GI) tract, lungs, and heart. Injury to the endothelial cells of these small blood vessels is followed by thickening of the vessel walls. The lumen subsequently narrows and eventually the vessels obliterate. This vascular injury ultimately results in chronic ischemia to the skin and organs.

The mechanism behind the vascular injury is unknown, but it involves derangement of normal immune function. Cytotoxic factors for blood vessel

endothelium cause collagen release and has been found in some patients with SCC. In addition, increased levels of macrophages and T cells are found in the lesions associated with SCC.

The earliest clinical symptom of SCC in Raynaud’s phenomenon, a condition caused by ischemia to the digits and yielding blanching, cold sensations, swelling and eventual rewarming of the fingers and toes. The earlobes and tip of the nose are also sites prone to develop Raynaud’s phenomenon.

Digit involvement is followed by swelling of the limbs. Telangiectasias of the skin develop on the face, fingers, lips, and tongue. The fingers and knees become stiff. Bloating and abdominal pain occur when the GI tract becomes involved. Lung involvement includes dyspnea, coughing, and pneumonia. SCC can result in heart failure, renal failure and hypothyroidism. SCC frequently causes dry eyes, and all patients seen with keratitis sicca should be queried about Raynaud’s phenomenon symptoms.

Laboratory testing reveals an elevated erythrocyte sedimentation rate and anemia. In 25% of cases of SCC, the patient has an elevated RF.

Most cases are diagnosed on the basis of Raynaud’s phenomenon in association with typical skin lesions (Figure 13-20). The course of the disease is highly variable.

No cure exists for SCC. Pharmacological intervention has included the use of D-penicillamine, azathioprine,

FIGURE 13-20 ■ Scleroderma. Note the classic signs of the tight skin over the forehead, nose, and cheeks, giving a “pinched” facial appearance and a reduced palpebral aperture size. (From Cawson RA, et al: Pathology: the mechanisms of disease, St Louis, 1989, Mosby Year-Book.)

methotrexate, cyclophosphamide, aspirin, and glucocorticoids. All of these agents have been shown to offer some benefits, but control studies are still lacking.

Ocular dryness in cases of SCC is best managed with tear substitutes. The use of oral flaxseed oil and omega-3 fish oil capsules has been advocated for the relief of dry eye, but control studies are lacking.

Ankylosing Spondylitis

Ankylosing spondylitis (AS) is characterized by inflammation involving the distal joints and central skeleton. As one of the spondylarthropathies, AS shares with other immune disorders an association with the HLA-B27 allele. In fact, 90% of patients with AS have inherited this antigen.

In AS the ligamentous attachment to bone, or enthesis, is the primary site of involvement. Lesions are found most often in the sacroiliac joint and between the vertebrae of the spine.

The earliest manifestation of AS is sacroiliitis. The lesions consist of lymphocytes, mast cells, and macrophages, along with bone marrow edema. New bone formation occurs within the ligamentous lesions. The joint becomes swollen and is eventually replaced by fibrocartilage. Ossification results in complete obliteration of the joint.

At least 20% of patients with AS develop an acute anterior uveitis, or iritis. The associated iritis is often an acute anterior uveitis with formation of a plasmoid aqueous and hypopyon. The pupil may be secluded by an immune membrane. The iritis may be the first clinical sign heralding the presence of AS.

The cause of AS is unknown, but it is thought that the inherited HLA-B27 allele predisposes the patient to develop the inflammation because of exposure to an environmental stimulus, most likely an enteric bacteria.

AS occurs most often in the years from the late teens to age 30, with a median patient age of 23 years. Women are affected slightly more often than men.

The earliest symptom is an intermittent, dull, lower back pain that is worse in the morning. The morning stiffness can last a few hours. Within months the pain becomes constant and boring.

AS has a variable course and patients can have mild, persistent lower back pain with minimal complications, or total fusion of the vertebrae known as “bamboo spine.” Spinal fractures may occur with even minor trauma. The posture of the patient becomes hunched-over and rigid.

Laboratory testing for AS can reveal the presence of the HLA-B27 allele, elevated sedimentation rate, and C-reactive protein. Elevated alkaline phosphatase occurs in severe cases of AS, and RF and antinuclear antibody tests (ANA) are typically negative. Radioimaging reveals sacroiilitis and other joint involvement.

Treatment of AS aims to maintain good posture, mobility, and motility, provide for a significant range of motion, and reduce pain. To this end, exercise, hot baths, massage therapy, and smoking cessation have all led to an improved lifestyle for patients with AS. Symptomatic relief can be achieved by use of antiinflammatory medications. Oral NSAIDs may reduce morning stiffness, and glucocorticoid injections into the sacroiliac joint provide temporary pain relief.

Treatment of AS-associated iritis makes use of topical steroids and cycloplegic agents, with topical phenylephrine for breaking posterior synechiae or secluded pupil.

Reactive Arthritis

Once known as Reiter’s syndrome, reactive arthritis (ReA) demonstrates the classic constellation of signs including arthritis, urethritis, and conjunctivitis. Mucocutaneous lesions are also associated with the classic presenting signs of ReA in 78% of cases.

The arthritis typically occurs in a patient with the HLA-B27 allele and follows infection by, for example, salmonellae or chlamydiae. ReA occurs in patients in the age range from 18 to 40 years, and is seen equally in men and women.

ReA is an inflammatory arthropathy with lesion formation similar to AS. It is believed, but has yet to be proven, that intracellular bacteria are protected by the HLA-B27 allele, and that this permits infected white blood cells to migrate to the joints in which the arthritis occurs because of a T cell response to the bacterial antigens.

The clinical features of ReA are highly variable, but a thorough history usually reveals a significant infection 1 week to 1 month before the onset of symptoms. At first, the patient experiences fatigue, malaise, weight loss, and fevers. The arthritis is acute in onset, and a new joint is involved every 1 to 2 weeks. The peripheral joints, including the knees, ankles, wrists, and fingers, are most often affected. The joint involvement may reoccur and cause persistent and incapacitating pain.

An accompanying urethritis (urinary tract infection) with symptoms of urinary urgency and increased urination frequency is often associated with the arthritis. A genitourinary discharge may also be present.

Other systemic associations include skin lesions on the palms (Figure 13-21) and soles, genital ulcers, oral ulcers, and heart and lung complications.

An acute plastic iritis may be associated with ReA, and can be refractory to treatment. Even with appropriate and aggressive treatment, subsequent corneal meltdown can occur that leads to blindness.

Laboratory findings will reveal an elevated erythrocyte sedimentation rate, mild anemia, a positive

FIGURE 13-21 ■ Keratoderma blennorrhagicum. Hyperkeratotic lesions of the foot in Reiter’s syndrome. (From Goldman L, Ausiello D: Cecil textbook of medicine, ed 22, Philadelphia, 2004, Saunders.)

HLA-B27 allele in approximately 75% of ReA cases, and radiographic confirmation of joint involvement.

The goal of ReA treatment is the relief of pain, and this is often accomplished by the use of NSAIDs. In general, glucocorticoids are avoided in cases of ReA unless the patient is confined to bed. Antibiotics have not been shown to play a role in the treatment of ReA. ReA caused by chlamydial infection should be treated with oral azithromycin 1000 mg for 1 day, and all sexual partners should be contacted for treatment. As with AS, physical therapy and exercise are encouraged to strengthen the muscles to the involved joints.

Wegener ’s Granulomatosis

This vasculitis of the upper and lower respiratory tract is characterized by granulomatous deposition within the small arteries and veins. The kidneys may also be involved. Typical symptoms include nosebleeds with sinus pain, ear pain, skin lesions, and coughing.

In 50% of cases of Wegener’s granulomatosis ocular involvement exists, including conjunctivitis, dacryocystitis, episcleritis, and proptosis. An associated granulomatous uveitis with mutton-fat keratic precipitates may be present

Laboratory testing will reveal an elevated ESR, anemia, elevated RF, and thrombocytosis.

Although once incurable and fatal in all cases, Wegener’s granulomatosis is now treated with cyclophosphamide for 1 year combined with oral glucocorticoids during the first 6 months of treatment. This treatment results in complete remission in 75% of cases. Approximately 50% of remission cases relapse eventually, and although these cases are again treated, permanent complications increase, including renal insufficiency, hearing loss, and throat scarring. Azathioprine may help maintain remission.

VASCULAR AUTOIMMUNE DISEASE

Inflammation and damage to the blood vessels characterizes vascular autoimmune disease, or vasculitis. Typically, narrowing or obliteration of the vessel lumen and consequential ischemia to tissues downstream occurs. The immune system appears to mediate the damage, to some extent, in almost all cases of vasculitis. A deposition of immune complexes into the blood vessel wall occurs in vasculitis. The antigen that stimulates the immune response has not been identified in most cases, although hepatitis B immunogen has been identified in patients with polyarteritis nodosa (Figure 13-22).

Temporal Arteritis

Also known as giant cell arteritis (GCA) or cranial arteritis, this vasculitis is characterized by inflammation of the mediumand large-sized arteries throughout the body. The most commonly affected sites include the branches of the carotid artery, especially the temporal artery (Figure 13-23). One of the most serious complications of GCA is a profound vision loss that is the result of arteritic ischemic optic neuropathy.

Typical of autoimmune vasculitis, the arterial walls become thickened by granulomatous deposition and giant cell formation and infiltration resulting in luminal narrowing. Obliteration of the lumen will result in ischemia of downstream tissues.

FIGURE 13-23 ■ Swelling of the optic nerve head in a patient with temporal arteritis.

GCA is found most often in the Scandinavian populations around the world. The disease is more common in women than in men and tends to be rare in blacks. There is an association with the HLA-DR4 allele. GCA occurs most often in patients older than 55 years and is most common in the elderly population of patients 70 years and older.

Systemic involvement of the extracranial arteries, the aorta, subclavian arteries, and coronary arteries lead to the systemic manifestations of GCA. These symptoms include fever, anemia, headaches, malaise, anorexia, and bodywide muscle pain.

Involvement of the temporal artery causes headache and a thickened, palpable, and tender temporal artery. Pain of the scalp upon palpation or chewing may occur. These symptoms can occur for months before vision is affected.

The most feared complication of GCA is ischemic optic neuropathy with subsequent vision loss. The vision loss is usually unilateral and is often accompanied by headache. Other systemic findings on examination for visual loss include a palpable, nodular, and tender temporal artery, fever, malaise, diffuse joint or muscular pain, and pain on chewing.

Ocular work-up of a unilateral case of temporal arteritis usually begins when the elderly patient is seen for an emergency examination with a sudden onset of vision loss and headache. Visual acuities may be reduced to 20/400 or worse in the involved eye. A relative afferent pupillary defect (RAPD), or Marcus Gunn pupil, will be present in the involved eye. Fundus evaluation may reveal a pale, swollen disc (disc edema), or a central retinal artery occlusion (CRAO). Visual fields reveal a classic altitudinal visual field defect in the involved eye.

Laboratory testing must be instituted on an emergency (stat) basis. Lab findings include an elevated erythrocyte sedimentation rate (by Westergren tech-

nique) and C-reactive protein. The diagnosis of GCA is confirmed by temporal artery biopsy with serial sectioning of the vessel so that inflamed areas are not missed.

The treatment of a suspected case of GCA should not wait until biopsy confirmation of the condition. The goal of treatment is to reduce the risk of contralateral temporal artery involvement and vision loss in the uninvolved eye. If the condition is strongly suggested by vision loss, temporal artery tenderness, headache, and disc edema, then treatment should be instituted and continued even if the biopsy results are normal. GCA is amenable to glucocorticoid therapy. Oral prednisone is begun at 60 to 120 mg per day for 1 month, followed by a taper to a maintenance dose of 10 mg per day. Some studies suggest that for the first 5 days, 1 gram of intravenous methylprednisolone should be given daily, and then oral glucocorticoids should be started on the sixth day. Treatment should continue for 1 to 2 years. The ESR and C-reactive protein are used to monitor the effectiveness of the treatment and help to determine the appropriate tapering schedule.

INFLAMMATORY AUTOIMMUNE DISEASE

Autoimmune disease may affect various organ tissues throughout the body. In most cases the causes remain unknown, but an exaggerated immune response to an unknown antigen is usually present.

Sarcoidosis

This multisystem, granulomatous disease is characterized by the accumulation of T cells and phagocytes in otherwise normal tissue. The cause of the condition is unknown, but a definite immune response is present to an as yet unknown antigen. The most common site of inflammation is the lung, thus it is believed that the antigen is inhaled.

This common disease affects males and females equally and occurs in all age ranges, although it is most commonly found in patients between the ages of 20 and 40 years. All races are affected, although in the United States the condition is more frequent in blacks. Despite the lung involvement, the condition is more common in nonsmokers.

The most common site of involvement is the respiratory tract and the most frequent presenting symptom is a cough. Early systemic manifestations include fever, malaise, fatigue, and anorexia. Other organ systems that commonly are involved include the lymph nodes, skin, liver, and eyes.

In the lung, the inflammation involves the alveoli, bronchi, and small blood vessels. Dyspnea can occur with exercise and is accompanied by a dry cough.