Sarcoidosis is a multisystem inflammatory disease of unknown cause, characterised by the formation of non-caseating granulomas (clusters of immune cells) in affected organs. The lungs and mediastinal lymph nodes are involved in approximately 90% of cases, but virtually any organ can be affected — eyes, skin, liver, heart, nervous system, kidneys and joints. The condition most commonly affects adults aged 20-40 years, with higher prevalence in Scandinavian populations and in people of African descent (who tend to have more severe disease). Sarcoidosis has a highly variable natural history — approximately 50% of patients have spontaneous remission; a minority develop chronic progressive disease.

How is sarcoidosis diagnosed?

Sarcoidosis is diagnosed by: (1) Compatible clinical and radiological picture (bilateral hilar lymphadenopathy ± pulmonary infiltrates on CXR/CT). (2) Histological confirmation of non-caseating granulomas from tissue biopsy (transbronchial biopsy, EBUS-guided lymph node sampling, skin biopsy, conjunctival biopsy or peripheral lymph node biopsy). (3) Exclusion of other granulomatous diseases — particularly tuberculosis (TB granulomas are caseating; AFB culture and IGRA testing); berylliosis (occupational history); fungal infections; lymphoma; hypersensitivity pneumonitis. Exception: Löfgren's syndrome (bilateral hilar lymphadenopathy + erythema nodosum + acute ankle arthritis) is sufficiently specific that it can often be diagnosed without biopsy.

Does sarcoidosis always need treatment?

No — approximately 50% of pulmonary sarcoidosis resolves spontaneously without treatment, and treatment is not without side effects (corticosteroid toxicity). Indications for treatment: Pulmonary: progressive decline in lung function (spirometry); symptomatic dyspnoea. Cardiac: heart block, arrhythmia, or impaired LV function. Ocular: posterior uveitis or anterior uveitis not responding to topical treatment. Neurological: any neurological involvement. Hypercalcaemia. Hepatic: significant liver function impairment. Severe symptomatic skin involvement (excluding erythema nodosum, which resolves spontaneously). Monitoring without immediate treatment ("watchful waiting") is appropriate for: asymptomatic Stage I or II pulmonary sarcoidosis; erythema nodosum (resolves); mild isolated lymphadenopathy.

What is cardiac sarcoidosis and why is it dangerous?

Cardiac sarcoidosis occurs when granulomas infiltrate the myocardium — most commonly the interventricular septum and LV free wall. It is dangerous because it causes: Complete heart block: granulomas disrupt the electrical conduction system → sudden-onset syncope or cardiac arrest; requires pacemaker implantation. Ventricular tachycardia/fibrillation: granulomas create arrhythmogenic scarring → sudden cardiac death in young adults — a major cause of non-ischaemic SCD. LV systolic dysfunction: extensive infiltration → dilated cardiomyopathy → heart failure. Cardiac sarcoidosis can occur without obvious pulmonary disease — making it particularly dangerous. Any young adult with complete heart block without explanation, or any sarcoidosis patient with palpitations, syncope or dyspnoea, requires cardiac MRI and electrophysiology evaluation.

How is sarcoidosis treated?

Corticosteroids (prednisolone) are the cornerstone: starting dose 20-40mg/day, tapering over 6-24 months. Side effects of long-term corticosteroids (diabetes, osteoporosis, weight gain, hypertension, cataracts) must be managed proactively. Steroid-sparing agents (to reduce cumulative steroid dose): methotrexate (most widely used); hydroxychloroquine (especially for skin and calcium); azathioprine. Biologic therapy for refractory disease: infliximab (anti-TNF) — the most evidence-based biologic for sarcoidosis. Cardiac sarcoidosis: ICD implantation for VT/VF risk + pacemaker for heart block + corticosteroids for active inflammation. Lung transplantation: for end-stage sarcoidosis (Stage IV fibrosis) with respiratory failure — sarcoidosis can recur in the transplanted lung.

How does GMJ News cover sarcoidosis?

GMJ News covers the multisystem involvement, Löfgren's syndrome, Scadding CXR staging, non-caseating granuloma, cardiac sarcoidosis (sudden death risk), ACE and hypercalcaemia, EBUS biopsy, corticosteroid treatment and tapering, steroid-sparing agents, infliximab for refractory disease, ocular sarcoidosis and uveitis, and neurosarcoidosis. Sarcoidosis is directly relevant to PHIG's respiratory and rare disease programme and the critical differential with tuberculosis in Georgia's epidemiological context.

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Sarcoidosis

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

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Sarcoidosis — a multisystem granulomatous disease of unknown aetiology characterised by non-caseating granulomas that can affect virtually any organ but predominantly the lungs (in approximately 90% of cases), mediastinal lymph nodes, skin and eyes — is the most common primary lung disease to be confused with lymphoma or malignancy on imaging, and the most treatable cause of sudden cardiac death after HCM in young adults (through cardiac sarcoidosis — complete heart block and ventricular arrhythmia) — yet remains underdiagnosed and undertreated globally due to its protean clinical presentation (WHO). Corticosteroids (prednisolone) remain the cornerstone of treatment for symptomatic or progressive sarcoidosis, while the characteristically dramatic clinical syndrome of Löfgren’s syndrome (bilateral hilar adenopathy + erythema nodosum + acute arthritis — the most specific sarcoidosis presentation) often resolves spontaneously without treatment.

Key messages

Lung #1 (90%) — but cardiac sarcoidosis can kill silently

Sarcoidosis affects the lungs in approximately 90% of cases — but cardiac sarcoidosis, occurring in approximately 5% (clinically recognised) to 25% (autopsy) of patients, can cause complete heart block, ventricular arrhythmia and sudden cardiac death. Cardiac sarcoidosis is significantly underdiagnosed — cardiac MRI and FDG-PET/CT are essential investigations when cardiac symptoms or arrhythmia occur in a sarcoidosis patient.

Löfgren's syndrome — the most specific sarcoidosis presentation

Löfgren's syndrome: the acute sarcoidosis triad of bilateral hilar lymphadenopathy (on chest X-ray) + erythema nodosum (tender red nodules over the shins) + acute arthritis (typically ankle periarthritis) ± fever. Predominantly in Nordic white women. High specificity for sarcoidosis — often does not require tissue biopsy for diagnosis. Excellent prognosis: approximately 90% resolve spontaneously within 2 years.

Non-caseating granuloma — the histological hallmark

Sarcoidosis granulomas are non-caseating (no central necrosis) — distinguishing them from TB granulomas (which are caseating/necrotic). The granuloma consists of: central core of macrophages/epithelioid cells → surrounded by lymphocytes → may contain giant cells (Langhans type, asteroid bodies or Schaumann bodies). Tissue biopsy (bronchoscopy with BAL + TBFB, skin, peripheral lymph node, conjunctival biopsy) confirms diagnosis.

Corticosteroids — the cornerstone, but not always needed

Oral prednisolone is the first-line treatment for sarcoidosis requiring therapy. However, approximately 50% of pulmonary sarcoidosis resolves spontaneously without treatment. Indications for treatment: progressive or severe pulmonary disease; cardiac involvement; ocular involvement; neurological involvement; hypercalcaemia; symptomatic hepatic involvement; significant skin disease (except EN). Starting dose: prednisolone 20-40mg/day × 4-6 weeks → taper to 5-10mg/day maintenance over months.

The chest X-ray staging — Scadding stages I-IV

Scadding radiological staging: Stage 0: normal CXR. Stage I: bilateral hilar lymphadenopathy (BHL) alone. Stage II: BHL + pulmonary infiltrates. Stage III: pulmonary infiltrates without BHL. Stage IV: pulmonary fibrosis. Higher stage does NOT necessarily mean worse prognosis — Stage I has the best spontaneous remission rate; Stage IV (fibrotic) is irreversible. Spontaneous remission: Stage I approximately 60-80%; Stage II approximately 50-60%; Stage III approximately 30%.

Serum ACE — elevated but not specific or diagnostic

Serum angiotensin-converting enzyme (ACE) is elevated in approximately 60% of active sarcoidosis (produced by epithelioid cells in granulomas). However: elevated ACE is not specific (also elevated in TB, berylliosis, histoplasmosis, Gaucher's disease); normal ACE does not exclude sarcoidosis; ACE is used to monitor disease activity and treatment response, not as a primary diagnostic test. Hypercalcaemia (from calcitriol 1,25-OH2D3 produced by activated macrophages in granulomas) + elevated ACE + bilateral hilar lymphadenopathy on CXR = the classic diagnostic triad.

Key statistics

~90%

of sarcoidosis patients have pulmonary involvement

ERS/ATS

~5-25%

have cardiac sarcoidosis (clinically recognised to autopsy rate)

ESC/Cardiology

Löfgren's

syndrome: BHL + erythema nodosum + acute arthritis — ~90% spontaneous resolution

ERS/ATS

~60%

ACE elevated in active sarcoidosis — monitors activity but not diagnostic

ERS/ATS

Stage I

60-80% spontaneous remission; Stage IV (fibrosis) — irreversible

Scadding/ERS

Non-caseating

granuloma — histological hallmark; distinguishes from TB (caseating)

Pathology/ERS

Sarcoidosis organ involvement — frequency and clinical significance

Source: ERS/ATS. Lungs dominate; cardiac and neurological involvement have highest mortality.

Glossary of key terms

Cardiac sarcoidosis
ESC/CardiologyGranulomatous infiltration of the myocardium — most commonly affecting the interventricular septum and free wall. Clinical manifestations: complete heart block (sudden onset syncope; 3rd-degree AV block; pacing required); ventricular arrhythmia (VT/VF — major cause of SCD in young adults with sarcoidosis); systolic dysfunction (if extensive infiltration); pericardial effusion (rare). Diagnosis: CMR (late gadolinium enhancement in non-ischaemic pattern — mid-wall or epicardial); FDG-PET/CT (active granulomas show high FDG uptake); endomyocardial biopsy (low sensitivity — patchy distribution). Treatment: corticosteroids (suppress active granulomas) + ICD (for high arrhythmia risk). Complete heart block in a young patient (<50) with no obvious cause → think sarcoidosis.

Hypercalcaemia in sarcoidosis
Endocrinology/SarcoidosisActivated macrophages within sarcoidosis granulomas express 1-alpha-hydroxylase — converting 25(OH)D to active calcitriol [1,25(OH)2D3] autonomously and independent of PTH. This causes: hypercalcaemia (approximately 10-11% of sarcoidosis patients) and/or hypercalciuria (approximately 40%). Consequences: nephrolithiasis (kidney stones); nephrocalcinosis; renal impairment; polyuria, polydipsia; fatigue, nausea. Management: corticosteroids rapidly suppress granulomatous 1-alpha-hydroxylase activity → corrects hypercalcaemia. Important: avoid vitamin D supplements in sarcoidosis (will worsen hypercalcaemia by providing more substrate).

Ocular sarcoidosis
Ophthalmology/SarcoidosisEye involvement in approximately 25% of sarcoidosis — the most common extra-pulmonary manifestation in some series. Anterior uveitis (most common — iritis: painful red eye, photophobia, miosis, cells in anterior chamber — treated with topical steroids + mydriatics). Posterior uveitis (choroiditis, retinal vasculitis — more sight-threatening; requires systemic steroids). Lacrimal gland enlargement. "Heerfordt's syndrome" (uveoparotid fever): bilateral parotid enlargement + anterior uveitis + facial nerve palsy + fever. All sarcoidosis patients should have a baseline slit-lamp ophthalmic examination.

Neurosarcoidosis
Neurology/SarcoidosisNervous system involvement in approximately 5% of sarcoidosis — with the highest morbidity and mortality of all sarcoidosis manifestations. Most common: cranial nerve palsies (facial nerve palsy — most common; optic neuritis); aseptic meningitis; space-occupying granulomas (hypothalamic — causes diabetes insipidus, neuroendocrine dysfunction); spinal cord compression; peripheral neuropathy. Diagnosis: CSF analysis (elevated protein, lymphocytic pleocytosis, elevated ACE); MRI brain/spine with gadolinium (leptomeningeal enhancement, parenchymal granulomas). Treatment: high-dose IV methylprednisolone + oral prednisolone; methotrexate or infliximab for refractory cases.

Second-line sarcoidosis therapies
ERS/ATSFor corticosteroid-refractory or corticosteroid-intolerant sarcoidosis: Methotrexate (most widely used steroid-sparing agent; 10-15mg/week + folic acid; monitor liver function and blood count). Hydroxychloroquine (particularly effective for sarcoid skin and hypercalcaemia; monitoring ophthalmological side effects). Azathioprine (alternative to methotrexate). Anti-TNF biologics: Infliximab (the most evidence-based biological — effective for pulmonary and extra-pulmonary refractory sarcoidosis; NEJM 2006 trial); adalimumab (alternative). Reserve biologics for treatment-refractory, corticosteroid-dependent sarcoidosis.

Transbronchial biopsy and EBUS
Respiratory/ProcedureBronchoscopy with transbronchial lung biopsy (TBLB) + bronchioalveolar lavage (BAL): the first-line diagnostic procedure for pulmonary sarcoidosis. BAL: elevated CD4:CD8 ratio (>3.5 — characteristic but not diagnostic). TBLB: diagnostic yield approximately 60-80% for endobronchial/peribronchial disease (which sarcoidosis typically is). EBUS (endobronchial ultrasound-guided transbronchial needle aspiration — EBUS-TBNA): sampling of mediastinal and hilar lymph nodes — very high diagnostic yield (approximately 80-90%) with minimal risk; has largely replaced mediastinoscopy for sarcoidosis diagnosis. Skin or peripheral lymph node biopsy: the easiest biopsy if accessible lesions are present.

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