Page 1037 - Clinical Immunology_ Principles and Practice ( PDFDrive )

1000 Part seven Organ-Specific Inflammatory Disease

manifestation of infection, such as herpes zoster ophthalmicus, In choosing to treat with oral corticosteroid or an immunosup-
syphilis, Lyme disease, tuberculosis, or other bacterial and fungal pressive, the clinician will, of course, weigh the risk/benefit ratio.
infections. The rationale for aggressive therapy is much stronger if the disease
is bilateral and is affecting activities of daily living, because of
Immunology and Pathology pain or reduction in acuity.
Biopsy of the sclera entails some risk. Accordingly, many of the
published histological observations are based on end-stage or
extremely severe disease. In one pathology study of 55 examples CLInICaL PearL
of necrotizing scleritis, the histology was divided into four types: Although noninfectious scleritis may be considered a vasculitis of the
zonal necrotizing granulomatous scleritis; nonzonal diffuse deep episcleral vessels, oral nonsteroidal antiinflammatory drugs (NSAIDs)
scleritis; necrotizing scleritis with microabscesses; and sarcoidal are effective in its treatment, and when the disease is refractory, oral
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granulomatous scleritis. Eighty-five percent of patients with corticosteroids, antimetabolites, or biologics can be quite effective.
zonal necrotizing granulomatous pathology had a systemic disease,
usually rheumatoid arthritis. The pathology associated with RA
was not distinct from other systemic diseases, such as GPA. None Evaluation and Differential Diagnosis
of 19 patients with nonzonal diffuse scleral inflammation had Patients with scleritis generally have characteristic findings that
a systemic disease. Just over half the patients with microabscesses allow an accurate diagnosis; scleritis can usually be readily
had an identifiable infection as the cause of scleritis. Only one distinguished from other causes of a red, painful eye. The most
patient had “sarcoidal granulomatous inflammation,” and that difficult distinction is between scleritis and episcleritis. The
patient had sarcoidosis. differences between scleritis and episcleritis are highlighted in
Table 74.5.
Prevention and Management The scleritis associated with a systemic vasculitis is often more
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Topical medications are only slightly beneficial for most patients severe than scleritis not associated with a systemic illness. The
with scleritis. Topical nonsteroidal antiinflammatory drugs scleritis associated with GPA may be particularly destructive and
(NSAIDs), such as ketorolac, have not been proven efficacious. refractory to therapy. Scleritis in association with RA is often a
A topical corticosteroid can sometimes help in symptomatic poor prognostic sign. Before the routine use of disease-modifying
control but also has risk, especially the promotion of cataract antirheumatic drugs, the small subset of patients with scleritis
formation and elevation of intraocular pressure. The role for in association with RA had a shortened life expectancy compared
topical cyclosporine has not been adequately evaluated, but the with those without evidence for ocular involvement.
authors’ clinical experience has not been favorable. Posterior scleritis can be an extremely difficult disease to
Although most forms of scleritis represent a vasculitis, oral diagnose. If the anterior sclera is uninvolved, no redness is present.
NSAIDs can be immensely beneficial. Although not all patients Pain with posterior scleritis is much more variable. The examina-
derive adequate control from oral NSAIDs, a subset will benefit tion may show elevation of the adjacent retina and choroid. The
sufficiently such that no other medication is required. We speculate diagnosis can be confirmed with an ultrasound examination or,
that the subset responsive to an NSAID might have a pathogenesis less commonly, with CT of the orbit demonstrating thickening
other than vasculitis, but this hypothesis remains unproven. of the sclera.
Many patients with scleritis will not benefit adequately from
an NSAID and will require immunosuppression. In general, Pitfalls and Controversy
for those with an associated systemic disease, pharmacologic Some experts believe that scleritis can sometimes be a forme
control of that disease will control the scleritis. For those without fruste of GPA. In patients with scleritis, a positive antineutrophil
a systemic illness, oral corticosteroids are an accepted initial cytoplasmic antibody (ANCA) test and no other evidence for
approach to treatment. For example, therapy might begin with GPA has been described. 45
a dose of prednisone of 1 mg/kg bodyweight per day. The use With the exception of the ANCA test, laboratory studies are
of calcium and vitamin D, as well as other measures to preserve generally selected according to the history and general physical
bone mineral density, should be considered for any patient who examination. For example, although RA is associated with scleritis,
will be receiving corticosteroid on a chronic basis. If prednisone the patients almost always have long-standing severe RA. A
is not adequate for disease control or if the medication is poorly rheumatoid factor and/or anticyclic citrullinated peptide antibody
tolerated and cannot be safely tapered to a modest dose, it is titer would not be appropriate tests if no joint disease were
reasonable to add a steroid-sparing medication. There is consider-
able interest in the use of biologic agents as corticosteroid-sparing
agents in scleritis. Multiple recently published case reports and TABLE 74.5 Contrasting Features of
small case series have described the successful use of drugs, scleritis and episcleritis
including TNF blockers or rituximab, in some patients with
resistant disease. 42 scleritis episcleritis
Locally injected corticosteroids may be effective for uveitis, Pain Prominent Minimal
but they are contraindicated for patients with necrotizing scleritis. Duration Years Days to months
The corticosteroid might enhance the likelihood that the necrotic Association with systemic disease Frequent Uncommon
sclera will perforate. However, for nonnecrotizing anterior scleral Vessels blanch with topical No Yes
inflammation, there is accumulating evidence that subconjunc- vasoconstrictor
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tivally injected corticosteroid is safe and may be highly effective. Associated ocular complications, Sometimes Rarely present
including visual loss
present
Scleral inflammation limited to the posterior sclera can probably Vessel color Violaceous Light pink
be safely treated with a periocular corticosteroid injection.