Differentials
Systemic lupus erythematosus (SLE)
SIGNS / SYMPTOMS
Photosensitivity more frequent in SLE.[21] Malar rash, nonspecific fever, prominent arthralgia and myalgia out of proportion to joint findings. Weight loss may be seen when disease is active.
INVESTIGATIONS
Positive anti-dsDNA antibodies.
Homogeneous antinuclear antibodies (ANAs) more likely in SLE than Sjogren syndrome, which more typically has a speckled ANA pattern.
Anti-La much less likely in SLE.
Rheumatoid arthritis
SIGNS / SYMPTOMS
Joint pains and morning stiffness, especially of hands and feet. Joint destruction and deformities possible.
INVESTIGATIONS
Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) both positive.
RF alone positive in about 50% of Sjogren syndrome.[21]
Hepatitis C
SIGNS / SYMPTOMS
May have none, may have history of exposure risk to contaminated blood. Chronic liver disease exam findings possible but not always present (enlarged or scarred liver, ascites, anasarca, jaundice, bleeding disorder, encephalopathy).
INVESTIGATIONS
Hepatitis C serology positive.
May also have abnormal liver enzyme or function testing.
Systemic sclerosis (scleroderma)
SIGNS / SYMPTOMS
Symmetric thickening and tightening of skin of fingers, possibly extending to entire upper extremity, and including face, neck, and trunk.
INVESTIGATIONS
Positive for Scl-70 antibodies.
Nucleolar pattern of antinuclear antibodies associated with scleroderma; however, homogeneous or speckled patterns also seen.
Hypothyroidism
SIGNS / SYMPTOMS
May include weight gain despite decreased appetite, change in hair or skin texture.
INVESTIGATIONS
Elevated serum thyroid-stimulating hormone, decreased serum T4.
Fibromyalgia
Depression
SIGNS / SYMPTOMS
May include mood changes, change in appetite, loss of interest in usual activities.
INVESTIGATIONS
None.
HIV
SIGNS / SYMPTOMS
History may include exposure risk factors such as unprotected sexual activity, intravenous drug use.
INVESTIGATIONS
HIV testing positive.
Sarcoidosis
SIGNS / SYMPTOMS
May include pulmonary symptoms such as cough, shortness of breath, bilateral hilar lymphadenopathy on chest imaging. Skin lesions may include nodules, erythema nodosum. Uveitis possible.
INVESTIGATIONS
Biopsy of lesion positive for sarcoid.
Drug-induced sicca
SIGNS / SYMPTOMS
History of treatment that can induce dry mouth, such as oral contraceptive, antidepressants, cholinesterase inhibitors, antipsychotics, benzodiazepines, diuretics, stimulants, or bronchodilators.
INVESTIGATIONS
None.
Idiopathic or age-related sicca
SIGNS / SYMPTOMS
None.
INVESTIGATIONS
Atrophic glands and extensive fibrosis on salivary gland biopsy.
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