A multisystemic, granulomatous (forming tumor-like masses) disease, sarcoidosis characteristically produces enlargement of lymph nodes (lymphoadenopathy), pulmonary infiltration, and skeletal, liver, eye or skin lesions. It occurs most often in young (ages 20 to 40). In the United States, sarcoidosis occurs predominantly among blacks, and effects twice as many women as men.
Acute sarcoidosis usually resolves within 2 years. Chronic, progressive sarcoidosis, which is uncommon, is associated with pulmonary fibrosis and progressive pulmonary disability.
CAUSES
Although the cause of sarcoidosis is unknown, the following possible causes are usually considered during the diagnosis:
- hypersensitivity response - (possibly a T-cell imbalance) to such agents as atypical mycobacteria, fungi and pine pollen.
- genetic predisposition
- chemicals such as zirconium or beryllium can lead to illness resembling sarcoidosis.
SIGNS & SYMPTOMS
Initial signs of sarcoidosis include pain 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)
- cutaneous - skin inflammation and rash, subcutaneous skin nodules, extensive nasal lesions
- ophthalmic - anterior uveitis, glaucoma, blindness (rare)
- lymphatic enlargement of lymph nodes and spleen
- musculoskeletal - muscle weakness, joint pain, punched-out lesions on phalanges (bones of the fingers and toes)
- hepatic - hepatitis (usually with no symptoms)
- genitourinary excess calcium in the urine
- cardiovascular irregular heart beats
- central nervous system meningitis, seizures, diabetes insipidus (due to pituitary and hypothalamic lesions)
TREATMENT
Sarcoidosis with no symptoms requires no treatment. However, sarcoidosis that causes ocular, respiratory, CNS, cardiac, or systemic symptoms (such as fever and weight loss) requires treatment with systemic or topical steroids, as does sarcoidosis that produces hypercalcemia or destructive skin lesions. Such therapy usually continues for 1 to 2 years but some patients may need lifelong therapy.
Other treatment includes a low-calcium diet and avoidance of direct exposure to sunlight in patients with hypercalcemia.