SARCOIDOSIS: AN UPDATE

Abstract

Sarcoidosis is a multisystemic disorder of unknown cause characterized by the formation of
immune granulomas in involved organs. It is an ubiquitous disease with incidence (varying
according to age, sex, race and geographic origin) estimated at around 16.5/100,000 in men
and 19/100,000 in women. The lung and the lymphatic system are predominantly affected but
virtually every organ may be involved. Other severe manifestations result from cardiac,
neurological, ocular, kidney or laryngeal localizations. Abnormal metabolism of vitamin D3
within granulomatous lesions and hypercalcemia are possible. Chest radiography is abnormal
in about 90% of cases and shows lymphadenopathy and/or pulmonary infiltrates (without or
with fibrosis).The etiology remains unknown but the prevailing hypothesis is that various
unidentified, likely poorly degradable antigens of either infectious or environmental origin
could trigger an exaggerated immune reaction in genetically susceptible hosts. Diagnosis
relies on compatible clinical and radiographic manifestations, evidence of non-caseating
granulomas obtained by biopsy through tracheobronchial endoscopy or at other sites, and
exclusion of all other granulomatous diseases. Mortality is estimated at between 0.5–5%. In
most benign cases (spontaneous resolution within 24–36 months), no treatment is required
but a regular follow-up until recovery is necessary. In more serious cases, a medical treatment
has to be prescribed either initially or at some point during follow-up according to clinical
manifestations and their evolution.