A 45-year-old woman presents with complaints of dry eyes and dry mouth for the past six months. She reports difficulty swallowing dry food and frequently uses artificial tears for relief. She also experiences joint pain and fatigue. On examination, her parotid glands are mildly enlarged. The ophthalmologist performs a Schirmer tear test, which shows markedly reduced tear production.
What is the most likely diagnosis for which the Schirmer tear test is used?
A. Glaucoma
B. Sjögren’s syndrome
C. Cataract
D. SLE
E. Systemic sclerosis
Correct Answer: B. Sjögren’s syndrome
Detailed Explanation:
The Schirmer tear test is primarily used to assess tear production and is a key diagnostic tool for Sjögren’s syndrome, a systemic autoimmune condition characterized by lymphocytic infiltration of exocrine glands. The test involves placing a filter paper strip under the lower eyelid to measure tear production over five minutes. A result of <5 mm of wetting is indicative of dry eyes, a hallmark of Sjögren’s syndrome.
Key Features of Sjögren’s Syndrome:
- Dry Eyes (Keratoconjunctivitis Sicca):
- Patients often complain of irritation, burning, and a gritty sensation.
- Schirmer tear test confirms reduced tear production.
- Dry Mouth (Xerostomia):
- Difficulty swallowing dry foods, increased dental caries, and parotid gland enlargement.
- Salivary gland scintigraphy or biopsy may help confirm glandular involvement.
- Systemic Manifestations:
- Fatigue, joint pain, and other organ involvement, such as interstitial lung disease or renal tubular acidosis.
- Autoantibodies:
- Anti-Ro/SSA and anti-La/SSB antibodies are commonly detected.
Why Other Options Are Incorrect:
A. Glaucoma
The Schirmer tear test is not used for glaucoma diagnosis. Glaucoma involves increased intraocular pressure or optic nerve damage, diagnosed using tonometry, visual field testing, or optic nerve imaging.
C. Cataract
Cataracts are caused by lens opacification, leading to blurred vision. Diagnosis is made using slit-lamp examination, not the Schirmer tear test.
D. SLE (Systemic Lupus Erythematosus)
While SLE may cause secondary Sjögren’s syndrome, the Schirmer test is not specific for diagnosing SLE. Diagnosis of SLE relies on clinical features and autoantibodies like ANA, anti-dsDNA, and anti-Smith antibodies.
E. Systemic sclerosis
Systemic sclerosis primarily involves skin thickening and organ fibrosis. Although it may cause sicca symptoms, the Schirmer test is not specific to systemic sclerosis.
Treatment for Sjögren’s Syndrome:
- Symptomatic management:
- Dry eyes: Artificial tears, punctal plugs, or cyclosporine eye drops.
- Dry mouth: Saliva substitutes, frequent hydration, or medications like pilocarpine.
- Systemic therapy:
- Hydroxychloroquine or immunosuppressants for systemic manifestations.