Sarcoidosis (in short)
- Sarcoidosis is a multisystemic disorder of unknown cause characterized by the formation
of immune granulomas in involved organs.
- It is an ubiquitous disease with frequency
(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.
- In most cases,
sarcoidosis is revealed by persistent dry cough, eye or skin manifestations, peripheral
lymph nodes, fatigue, weight loss, fever or night sweats, and erythema nodosum.
- 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), defining sarcoidosis stages from
I to IV.
- The causes 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.
- The evolution
and severity of sarcoidosis are highly variable. 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.
- Systemic corticosteroids
are the mainstay of treatment of sarcoidosis.
- The minimal duration of treatment is
12 months. Some patients experience repeated relapses and may require long-term low-dose
corticosteroid therapy during years.
- Other treatments (immunosuppressive drugs and
aminoquinolins) may be useful in case of unsatisfactory response to corticosteroids,
poor tolerance and as sparing agents when high doses of corticosteroids are needed
for a long time.
- In some strictly selected cases refractory to standard therapy, specific
antiTNF-α agents may offer precious improvement. Some patients benefit from topical corticosteroids.
- Authors: Hilario Nunes, Diane Bouvry, Paul Soler and Dominique Valeyre. Orphanet Journal of Rare Diseases