EXOPHTHALMOS
EXOPHTHALMOS: Excerpt from Differential Diagnosis in Primary Care
The mnemonic VINDICATE is a useful and quick way to recall the
causes of exophthalmos (for enophthalmos, see the section on ptosis, page 369).
V—Vascular disorders include a carotid–cavernous fistula and
cavernous sinus thrombosis.
I—Inflammatory diseases recall orbital cellulitis, osteomyelitis,
and sinusitis.
N—Neoplasms suggest hemangiomas, lymphangiomas, sarcomas, metastatic
carcinomas, and nervous system tumors such as sphenoid ridge meningiomas.
D—Deficiency diseases suggest the retroorbital hemorrhages of
scurvy. Degenerative diseases suggest the apparent exophthalmos of
facial palsy associated with progressive muscular atrophy and dystrophy in
many forms.
I—Intoxication suggests the exophthalmos that develops or progresses
on treatment in hyperthyroidism. Idiopathic diseases such as Paget
disease and fibrous dysplasia of the skull must also be considered.
C—Congenital brings to mind hydrocephalus,
Hand–Schüller–Christian disease, meningoceles, and cleidocranial
dystosis, all of which cause exophthalmos. In this category, one should also
include the genetic exophthalmos of blacks.
A—Autoimmune disorders suggest Wegener granulomatosis.
T—Trauma suggests orbital fractures and hematomas, which will cause
proptosis in many cases.
E—Endocrine disorders suggest that the most significant cause of
exophthalmos is Graves disease.
If exophthalmos can be classified as a result of a mass, then the
causes can be recalled by the methods applied to any mass. The mass may be
air (orbital emphysema), fluid (orbital abscess), blood (e.g., hematomas
from trauma, scurvy, hemophilia), a foreign substance (e.g., echinococcal
cyst), or hypertrophy of one of the tissues around the orbit. The latter can
be developed by a histologic analysis. Thus, fat may hypertrophy or
multiply in Hand–Schüller–Christian disease and in exophthalmic
goiter. Blood vessels may become hypertrophied in cavernous sinus
thrombosis, carotid–cavernous fistulas, and aneurysms and will undergo
hyperplasia in hemangiomas. Lymph tissue and connective tissue
may form sarcomas or granulomas. Bone may swell with a periosteitis
and may undergo hyperplasia in Paget disease, osteomas, metastatic
carcinoma, and meningiomas. Nerve tissue may undergo hyperplasia in
neurofibromatosis.
Approach to the Diagnosis
Because bilateral exophthalmos is usually due to hyperthyroidism, a
thyroid profile must be done. The most useful in this profile are the total
T4 level by immunoassay, the free thyroxine index, and the radioiodine
(RAI) uptake and scan. A total triiodothyronine (T3) test by immunoassay should be
done to exclude T3 thyrotoxicosis. Because bilateral exophthalmos can
occur without hyperthyroidism, testing for thyrotropin receptor antibody and
peroxidase antibodies must be done if thyroid function tests are negative.
With exophthalmos, chemosis, and ecchymosis, the patient should be
hospitalized for a workup of cavernous sinus thrombosis and a neurologist
consulted. When there is unilateral exophthalmos, ultrasonography and
angiography will rule out carotid–cavernous fistula and a cystic lesion. A
CT scan of the brain and orbits will rule out tumors and abscesses. It is
wise to consult a neurologist, ophthalmologist, or endocrinologist to assist
in this workup.
Pictures
Book Source Details
- Book Title: Differential Diagnosis in Primary Care
- Author(s): R. Douglas Collins MD, FACP
- Year of Publication: 2007
- Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2007 Lippincott Williams & Wilkins.
More About Graves Disease
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
» Next page: Goiter (The 5-Minute Pediatric Consult)
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