Sarcoidosis, is a granulomatosis of unknown origin, anergizing, considered as resulting
from an immune cell response, excessive to one or more antigens of exogenous origin,
or endogenous.
It can touch all the viscera with a preponderance for the respiratory tree.
Histologically, it achieves follicular inflammation, without any necrosis, associating epithelioid
cells, Langhans-like giant cells (often containing in their cytoplasm inclusions called asteroid
bodies and Schaumann bodies) and lymphocytes.
Clinical Manifestations: Sarcoidosis, is a rare disease, a little more common in women,
Mediastinopulmonary involvement affects more than 90% of patients.
The extrathoracic locations are rather ocular, cutaneous, ganglionic and hepatic.
General signs: Fatigue, asthenia can be deep, in the foreground,
or even isolated. Weight loss or fever are more atypical, except in cases of lofgren
syndrome, multiple organ dysfunction, or Heerfordt syndrome (associating parotitis, uveitis,
fever and facial paralysis).
General signs should search another diagnosis: cancer, infections, including
tuberculosis.
Lofgren syndrome: Characterized by a noisy clinic, however,
it is of good prognosis, and does not require histological confirmation for diagnostic purposes,
or use of corticosteroids. It is a 5 to 10% enhancer and combines bilateral and symmetrical
mediastino-hilar intrathoracic lymphadenopathy with thoracic radiography, a tuberculin anergy;
and a typical erythema nodosum (especially in women) or bilateral ankle arthritis (more
common in men). Its evolution occurs spontaneously towards
regression, in 1 to 2 years in 90% of the cases.
Heerfordt syndrome: (associating parotitis, uveitis, fever and
paralysis facial).
Pulmonary signs: Pulmonary auscultation is usually normal and
clubbing exceptional digital. Persistent cough is common if there is respiratory
damage (20 to 90% of cases). The dyspnoea, rare at the beginning, appears
in the advanced forms (20% of the observations). Pulmonary hypertension, H T A P (exercise
dyspnea, holosystolic murmur of tricuspid insufficiency, B2 shine in the pulmonary focus,
right heart failure) or haemoptysis are signs of severity.
Extrathoracic locations The most common are cutaneous, ocular, and
peripheral ganglion. The first may be plaques and nodules on scar, tattoo or subcutaneous.
Lupus pernio is defined by purple, infiltrated patches predominating on the nose and cheeks,
with a butterfly wing appearance.
Ocular lesions are acute, intermediate, or posterior uveitis, or optic neuritis (threatening
vision). Less common are splenomegaly or hepatomegaly,
parotitis, neurological, joint, cardiac, renal and nasosinusal disorders.
Kidney damage to sarcoidosis is rare but can progress to kidney failure. The two most common
mechanisms are tubulointerstitial nephropathy and acute hypercalcemic renal failure.
Hepatic disorders: Hepatic sarcoidosis exposes to two rare complications, observed in less
than 5% of cases: chronic cholestasis and portal hypertension.
Treatment is based primarily on corticosteroids, indicated in cases of symptomatic liver involvement
and / or extensive liver fibrosis. In the rare cases where portal hypertension has developed,
the specific treatment of oesophageal varices is required.
Specialized ophthalmological examination is essential.
Biological exploration: NFS, platelets,
blood ionogram, creatinine and urine test strip,
calcemia and calciuria of 24 hours, electrophoresis of blood proteins (polyclonal
hypergammaglobulinemia), liver test (cholestasis),
angiotensin converting enzyme (ACE), HIV serology, fasting glucose (pre-therapy).
Lymphopenia, and elevation of the angiotensin-converting enzyme, are signs of active disease.
Non-specific to sarcoidosis, and produced by granuloma macrophages, the angiotensin-converting
enzyme rises in about 60% of cases.
Hypercalcemia is indicative of macrophage synthesis of 1 alphahydroxylase granuloma
that converts 25-hydroxyvitamin D3 into calcitriol. This causes in 5 to 10% of the cases a hypercalcemia,
especially the summer (prolonged solar exposure) during an inappropriate prescription of vitamin
D or if there is a localization renal. The diagnosis is based on a clinical and radiographic
expression suggestive of non-caseous granulomas, confirmed histologically, after elimination
of other granulomatoses.
Tuberculin tests (IDR, and IGRA (Interferon Gamma Release Assays),
Search for mycobacteria (bronchial aspiration) Chest X-ray face and profile,
Functional Exploratory Exploration: (plethysmography, spirometry, transfer of co) are often normal.
In 30% of cases, there is a decrease in FVC, in 30 to 50% an obstructive ventilatory disorder,
and in 15 to 20% a decrease in the DLCO.
the chest scanner is indicated in case of clinical and / or non-characteristic
radiological picture, when the differential diagnosis is difficult (stage 3)
to guide the samples in endoscopy.
The face and profile chest X-ray is fundamental for diagnosis and prognosis.
It is abnormal in 90% of patients. The impairment is assessed by the Scadding
classification. Stage 0: normal x-ray;
stage 1: lymphadenopathy without parenchymal involvement; The probability of
spontaneous healing is 60-90%, stage 2: lymphadenopathy associated with parenchymal
involvement; The probability of spontaneous healing is 40-70%,
stage 3: isolated parenchymal involvement; The probability of spontaneous healing is
10-20%. stage 4: pulmonary fibrosis. The probability
of spontaneous recovery is 0%.
Optimized cytological diagnosis: Ultrasound bronchoscopic (or digestive) perendoscopic
lymph node cytology has replaced mediastinoscopy when it is not possible to easily obtain a
granuloma.
Possible for hilar or mediastinal intrathoracic lymphadenopathy, it is used when there is
no biopsiable superficial site (no cutaneous, peripheral or conjunctival lymph node involvement)
and traditional endoscopy with bronchial mucosal transbronchial biopsies. pulmonary is not
conclusive.
Its profitability is greater than 90%, optimized by the presence of a cytologist who guides
the procedure according to the diagnostic yield of the first samples in the extemporaneous
examination.
It has supplanted in 90% of cases mediastinoscopy.
Extended oral corticosteroid therapy is the main treatment (50% of patients), indicated
according to pulmonary involvement and the severity of extrathoracic locations.
Hygiene and dietary advice:
some preventive advice to patients with sarco idiosis.
Regular physical activity, limited salt diet (6 g / d, 2-4 g / d if PAH or heart failure).
Limit high glycemic index sugars. Influenza and pneumococcal vaccinations if
immunosuppressive therapy (corticosteroid therapy in particular) or pulmonary involvement
with functional impact. Limit sun exposure and intake of vitamin D
or calcium (in the form of medications, no more than 3 dairy products per day) in case
of hypercalcemia.
Evolution and prognosis:
Spontaneously resolving in the majority of the cases, the disease can engage the functional
prognosis (lung, eye, liver, kidney) and vital (lung, heart, CNS, larynx). Follow-up is necessary
until healing. The main causes of
death are severe cardiac and respiratory problems. heart, CNS, larynx). Follow-up is necessary
until healing. The main causes of death are serious cardiac
and respiratory problems.