Sarcoidosis is a multisystem, granulomatous disorder that characteristically produces lymphadenopathy, pulmonary infiltration, and skeletal, liver, eye, or skin lesions. Acute sarcoidosis usually resolves within 2 years. Chronic, progressive sarcoidosis, which is uncommon, is associated with pulmonary fibrosis and progressive pulmonary disability.
The cause of sarcoidosis is unknown, but these factors may play a role:
❑ hypersensitivity response (possibly from 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)
❑ extreme immune response to infection.
Sarcoidosis occurs most commonly in adults ages 30 to 50. In the United States, sarcoidosis occurs predominantly among blacks, affecting twice as many women as men.
Initial symptoms of sarcoidosis include arthralgia (in the wrists, ankles, and elbows), fatigue, malaise, and weight loss. Other clinical features vary according to the extent and location of the 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, and extensive nasal mucosal lesions
❑ ophthalmic — anterior uveitis (common), glaucoma, and blindness (rare)
❑ lymphatic — bilateral hilar and right paratracheal lymphadenopathy and splenomegaly
❑ musculoskeletal — muscle weakness, polyarthralgia, pain, and punched-out lesions on phalanges
❑ hepatic — granulomatous hepatitis, usually asymptomatic
❑ genitourinary — hypercalciuria
❑ cardiovascular — arrhythmias (premature beats, bundle-branch or complete heart block) and, rarely, cardiomyopathy
❑ central nervous system — cranial or peripheral nerve palsies, basilar meningitis, seizures, and pituitary and hypothalamic lesions producing diabetes insipidus.
Typical clinical features with appropriate laboratory data and X-ray findings suggest sarcoidosis. A positive skin lesion biopsy supports the diagnosis.
Other relevant findings include:
❑ chest X-ray — bilateral hilar and right paratracheal adenopathy with or without diffuse interstitial infiltrates; occasionally large nodular lesions present in lung parenchyma
❑ lymph node or lung biopsy — noncaseating granulomas with negative cultures for mycobacteria and fungi
❑ other laboratory data — rarely, increased serum calcium, mild anemia, leukocytosis, and hyperglobulinemia
❑ pulmonary function tests — decreased total lung capacity and compliance, and decreased diffusing capacity
❑ arterial blood gas (ABG) analysis — decreased arterial oxygen tension.
Negative tuberculin skin test, fungal serologies, and sputum cultures for mycobacteria and fungi as well as negative biopsy cultures help rule out infection.
Sarcoidosis that produces no symptoms requires no treatment. However, those severely affected with sarcoidosis require treatment with corticosteroids. Such therapy is usually continued for 1 to 2 years, but some patients may need lifelong therapy. Immunosuppressive agents, such as methotrexate, azathioprine, and cyclophosphamide, may also be used. If organ failure occurs (although this is rare), transplantation may be required. Other measures include a low-calcium diet and avoidance of direct exposure to sunlight in patients with hypercalcemia.
❑ Watch for and report any complications. Be aware of abnormal laboratory results (anemia, for example) that could alter patient care.
❑ For the patient with arthralgia, administer analgesics as ordered. 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 levels, observe for arrhythmias, and administer oxygen, as needed.
❑ Because steroids may induce or worsen diabetes mellitus, perform fingerstick glucose tests at least every 12 hours at the beginning of steroid therapy. Also, watch for other steroid adverse effects, such as fluid retention, electrolyte imbalance (especially hypokalemia), moon face, hypertension, and personality change. During or after steroid withdrawal (particularly in association with infection or other types of stress), watch for and report vomiting, orthostatic hypotension, hypoglycemia, restlessness, anorexia, malaise, and fatigue. Remember that the patient on 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: Professional Guide to Diseases (Eighth Edition) Authors: Springhouse Publisher: Lippincott Williams & Wilkins Copyright: 2005 ISBN: 1-58255-370-X 
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