Sarcoidosis-audio

Sarcoidosis is a multisystem, granulomatous disorder that characteristically produces lymphadenopathy, pulmonary infiltration, and skeletal, liver, eye, or skin lesions.
Causes
Exact cause unknown
Possible contributing factors
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)
Chemicals, such as zirconium and beryllium, which can lead to illnesses resembling sarcoidosis, suggesting an extrinsic cause for this disease
Pathophysiology
An excessive inflammatory process is initiated in the alveoli, bronchioles, and blood vessels of the lungs. Monocyte-macrophages accumulate in the target tissue, where they induce the inflammatory process. CD4+ T lymphocytes and sensitized immune cells form a ring around the inflamed area. Fibroblasts, mast cells, collagen fibers, and proteoglycans encase the inflammatory and immune cells, causing granuloma formation. Organ dysfunction results from the accumulation of T lymphocytes, mononuclear phagocytes, and nonsecreting epithelial granulomas, which distort normal tissue architecture, causing alveolitis.
Signs and symptoms
Initial symptoms of sarcoidosis include arthralgia (in the wrists, ankles, and elbows), fatigue, malaise, and weight loss. Sarcoidosis is characterized by formation of granulomatous tissue leading to pulmonary fibrosis. Other clinical features vary according to the extent and location of the fibrosis:
Respiratory—breathlessness, cough (usually nonproductive), and substernal pain; wheezing; pulmonary hypertension and cor pulmonale (in advanced pulmonary disease)
Cutaneous—erythema nodosum, subcutaneous skin nodules with maculopapular eruptions, and extensive nasal mucosal lesions
Ophthalmic—anterior uveitis (common) and glaucoma
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 and, rarely, cardiomyopathy
Central nervous system (CNS)—cranial or peripheral nerve palsies, basilar meningitis, seizures, and pituitary and hypothalamic lesions producing diabetes insipidus
Diagnostic test results
Arterial blood gas analysis shows a decreased partial pressure of arterial oxygen.
Chest X-rays show bilateral hilar and right paratracheal adenopathy, with or without diffuse interstitial infiltrates.
Lymph node, skin, or lung biopsy shows noncaseating granulomas with negative cultures for mycobacteria and fungi.
Pulmonary function tests show decreased total lung capacity and compliance and reduced diffusing capacity.
Treatment
No treatment for asymptomatic sarcoidosis
With ophthalmic, respiratory, CNS, cardiovascular, or systemic symptoms or destructive skin lesions: systemic or topical steroids, usually for 1 to 2 years, but possibly lifelong
With hypercalcemia: low-calcium diet and avoidance of direct exposure to sunlight

error: Content is protected !!

NEWNMCLE

NEWNMCLE