A multisystemic, granulomatous disorder, sarcoidosis characteristically produces lymphadenopathy, pulmonary infiltration, and skeletal, liver, eye, or skin lesions. It’s most common in young adults (ages 20 to 40). In the United States, sarcoidosis occurs predominantly among blacks and affects twice as many women as men.
Acute sarcoidosis usually resolves within 2 years. Chronic, progressive sarcoidosis is associated with pulmonary fibrosis and progressive pulmonary disability.
Although the cause of sarcoidosis is unknown, the following possible causes have been considered:
❑ hypersensitivity response (possibly from a T-cell imbalance) to such agents as atypical mycobacteria, fungi, and pine pollen
❑ genetic predisposition (suggested by a slightly higher incidence of sarcoidosis within the same family)
❑ chemicals, such as zirconium or beryllium, can lead to illnesses resembling sarcoidosis, suggesting an extrinsic cause for this disease.
Initial signs and symptoms of sarcoidosis include arthralgia (in the wrists, ankles, and elbows), fatigue, malaise, and weight loss. Other signs and symptoms vary according to the extent and location of fibrosis:
❑ respiratory — breathlessness, cough (usually nonproductive), substernal pain (complications in advanced pulmonary disease include pulmonary hypertension and cor pulmonale)
❑ cutaneous — erythema nodosum, subcutaneous skin nodules with maculopapular eruptions, extensive nasal mucosal lesions
❑ ophthalmic — anterior uveitis (common); glaucoma, blindness (rare)
❑ lymphatic — bilateral hilar and right paratracheal lymphadenopathy and splenomegaly
❑ musculoskeletal — muscle weakness, polyarthralgia, pain, punched-out lesions on phalanges
❑ hepatic — granulomatous hepatitis, usually asymptomatic
❑ genitourinary — hypercalciuria
❑ cardiovascular — arrhythmias (premature beats, bundle-branch block, or complete heart block); cardiomyopathy (rare)
❑ central nervous system (CNS) — cranial or peripheral nerve palsies, basilar meningitis, seizures, pituitary and hypothalamic lesions producing diabetes insipidus.
Typical signs and symptoms with appropriate laboratory data and X-ray findings suggest sarcoidosis. Biopsy is the most important diagnostic procedure. (Lymph node, skin, or lung biopsy reveals noncaseating granulomas with negative cultures for mycobacteria and fungi.)
Other relevant findings include the following:
❑ Chest X-ray shows bilateral hilar and right paratracheal adenopathy with or without diffuse interstitial infiltrates; occasionally, large nodular lesions are present in lung parenchyma.
❑ Angiotensin-converting enzyme levels may be elevated but are generally considered nonspecific in gauging the natural history of the disease.
❑ Other laboratory test results may reveal increased serum calcium level, mild anemia, leukocytosis, or hyperglobulinemia.
❑ Pulmonary function tests show decreased total lung capacity and compliance and decreased diffusing capacity.
❑ Arterial blood gas (ABG) analysis shows decreased partial pressure of arterial oxygen.
Negative tuberculin skin test, fungal serologies, and sputum cultures for mycobacteria and fungi, as well as negative biopsy cultures, help rule out infection.
Asymptomatic sarcoidosis requires no treatment. However, sarcoidosis that causes ocular, respiratory, CNS, cardiac, or systemic signs and symptoms (such as fever and weight loss) requires treatment with a systemic or topical steroid, as does sarcoidosis that produces hypercalcemia or destructive skin lesions. Such therapy is usually continued for 1 to 2 years, but some patients may need lifelong therapy. Other drugs sometimes used in addition to corticosteroids include immunosuppressants, methotrexate, azathioprine, and cyclophosphamide.
Other treatment includes a low-calcium diet and avoidance of direct exposure to sunlight in patients with hypercalcemia.
Rarely, some individuals with irreversible organ failure require organ transplantation.
❑ Watch for and report any complications. Be aware of any abnormal laboratory results (anemia, for example) that could alter patient care.
❑ If the patient has arthralgia, administer an analgesic as needed. Record signs of progressive muscle weakness.
❑ Provide a nutritious, high-calorie diet and plenty of fluids. If the patient has hypercalcemia, suggest a low-calcium diet. Weigh the patient regularly to detect weight loss.
❑ Monitor respiratory function. Check chest X-rays for the extent of lung involvement; note and record any bloody sputum or increase in sputum. If the patient has pulmonary hypertension or end-stage cor pulmonale, check ABG values, watch for arrhythmias, and administer oxygen as needed.
❑ Because steroids may induce or worsen diabetes mellitus, perform blood glucose tests every 12 hours at the beginning of steroid therapy. Also, watch for other adverse reactions to steroids, such as fluid retention, electrolyte imbalance (especially hypokalemia), moon face, hypertension, and personality change.
CLINICAL TIP: During or after steroid withdrawal (particularly in association with infection or other types of stress), watch for vomiting, orthostatic hypotension, hypoglycemia, restlessness, anorexia, malaise, and fatigue. Remember that the patient undergoing long-term or high-dose steroid therapy is vulnerable to infection.
❑ When preparing the patient for discharge, stress the need for compliance with prescribed steroid therapy and regular, careful follow-up examinations and treatment.
❑ Refer the patient with failing vision to community support and resource groups and the American Foundation for the Blind, if necessary.
Review other book chapters online related to Sarcoidosis:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: Handbook of Diseases Authors: Springhouse Publisher: Lippincott Williams & Wilkins Copyright: 2003 ISBN: 1-58255-266-5 
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