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Sarcoidosis

Clinical Subject Page

Sarcoidosis

Sarcoidosis is a multisystem inflammatory disease characterized by the formation of noncaseating granulomas, most commonly affecting the lungs and intrathoracic lymph nodes.

Also called

Sarcoid

ICD-10

D86.9

Specialty

Pulmonology

Onset

Chronic

Reviewed

July 2026

On This Page

Overview

Sarcoidosis can affect almost any organ, but most commonly involves the:

  • Lungs
  • Intrathoracic lymph nodes
  • Skin
  • Eyes

The disease results from an abnormal immune response to an unknown trigger in genetically susceptible individuals.

Etiology & Risk Factors

Etiology

The exact cause is unknown.

Sarcoidosis probably develops through an interaction between:

  • Genetic susceptibility
  • Environmental or infectious triggers
  • Abnormal immune response

Risk Factors

  • Young and middle adulthood
  • Family history of sarcoidosis
  • Certain genetic backgrounds
  • Exposure to specific environmental or occupational agents

Important Note

Sarcoidosis is not an infectious disease, although infectious agents may act as possible triggers.

Pathophysiology

Flow Chart

Unknown environmental or infectious trigger
⬇
Abnormal immune activation
⬇
Activation of T lymphocytes and macrophages
⬇
Accumulation of inflammatory cells
⬇
Formation of noncaseating granulomas
⬇
Organ inflammation and dysfunction
⬇
Granuloma resolution OR chronic inflammation
⬇
Fibrosis and permanent organ damage in some patients

Key Concept

The hallmark of sarcoidosis is the noncaseating granuloma.

Clinical Presentation

  1. General Symptoms

    • Fatigue
    • Fever
    • Weight loss
    • Night sweats

    Pulmonary Features

    • Dry cough
    • Progressive dyspnea
    • Chest discomfort
    • Wheezing

    Skin Features

    • Erythema nodosum
    • Lupus pernio
    • Papules or plaques

    Eye Features

    • Uveitis
    • Eye pain
    • Redness
    • Photophobia
    • Visual disturbance

    Other Features

    • Peripheral lymphadenopathy
    • Arthralgia or arthritis
    • Cardiac arrhythmias
    • Neurological symptoms
    • Hypercalcemia

History Taking

    • Ask about:

       

      Dry cough?

      Shortness of breath?

      Chest discomfort?

      Fever or night sweats?

      Weight loss?

      Fatigue?

      Skin rash or painful leg nodules?

      Eye pain or redness?

      Visual changes?

      Joint pain or swelling?

      Family history of sarcoidosis?

Physical Examination

  • Look for:

    • Peripheral lymphadenopathy
    • Erythema nodosum
    • Lupus pernio
    • Other skin lesions

    Chest Examination

    May show:

    • Fine crackles
    • Wheezing

    The chest examination may also be normal.

    Eye Examination

    Look for:

    • Eye redness
    • Signs of uveitis

    Other Examination

    Look for:

    • Joint swelling
    • Hepatomegaly
    • Splenomegaly
    • Neurological abnormalities
    • Signs of cardiac involvement

Investigations

  • Chest Imaging — Key Investigation

    Chest X-ray

    May show:

    • Bilateral hilar lymphadenopathy
    • Pulmonary infiltrates
    • Pulmonary fibrosis

    Chest CT

    Provides better assessment of:

    • Lymphadenopathy
    • Lung nodules
    • Parenchymal disease
    • Fibrosis

    Pulmonary Function Tests

    May show:

    • Restrictive pattern
    • Obstructive pattern
    • Reduced DLCO
    • Normal results

    Blood Tests

    May include:

    • CBC
    • Renal function
    • Liver function
    • Serum calcium
    • Vitamin D assessment when indicated

    ECG

    Used to screen for possible cardiac involvement.

    Tissue Biopsy

    May show:

    • Noncaseating granulomas

    Important Note

    Serum ACE levels are neither sensitive nor specific enough to confirm or exclude sarcoidosis.

Diagnosis

Sarcoidosis · Diagnostic Criteria & Stepwise Approach

DIAGNOSIS = COMPATIBLE CLINICAL/RADIOLOGICAL PICTURE + HISTOLOGICAL EVIDENCE OF NON-CASEATING GRANULOMAS + EXCLUSION OF ALTERNATIVE CAUSES Sarcoidosis is a multisystem granulomatous disease of unknown aetiology. There is no single diagnostic test — diagnosis requires the classic triad above.

Biopsy of the most accessible lesion is preferred. Löfgren syndrome (erythema nodosum + bilateral hilar lymphadenopathy + arthralgia) may be diagnosed clinically without biopsy.
Suspected Sarcoidosis → Is there compatible clinical or radiological presentation?
Stepwise Diagnostic Approach
1
Clinical Presentation
Dyspnoea, dry cough, fatigue, bilateral hilar LAD on CXR. Extrapulmonary: uveitis, skin lesions (erythema nodosum, lupus pernio), hypercalcaemia, parotid enlargement, facial nerve palsy.
Pattern recognition
2
CXR & HRCT
Bilateral hilar lymphadenopathy — classic. HRCT: perilymphatic nodules, upper/mid-lobe predominance, peribronchovascular distribution. Stages I–IV on CXR.
Imaging
3
Bloods & Investigations
Serum ACE (elevated in 60%), calcium (hypercalcaemia), LFTs, FBC (lymphopenia), 24h urine calcium, ECG (heart block), ophthalmic review, PFTs, urinalysis.
Supportive evidence
4
Histology
Non-caseating epithelioid granulomas with Langhans giant cells. Biopsy most accessible site — EBUS-TBNA of hilar nodes (first-line), skin biopsy, conjunctival biopsy, transbronchial biopsy. Surgical biopsy if others non-diagnostic.
Essential (usually)
5
Exclude Differentials
TB (Ziehl-Neelsen, culture — exclude caseating granulomas), fungal infection, hypersensitivity pneumonitis, lymphoma, berylliosis, Wegener's/vasculitis.
Mandatory
CXR Stage Radiological Findings Spontaneous Remission Rate
Stage 0 Normal chest radiograph — extrapulmonary disease only N/A
Stage I Bilateral hilar lymphadenopathy (BHL) alone — no parenchymal involvement 55–90% spontaneous remission
Stage II BHL + pulmonary parenchymal infiltrates 40–70% spontaneous remission
Stage III Pulmonary infiltrates without BHL 10–20% spontaneous remission
Stage IV Pulmonary fibrosis, honeycombing, bullae, traction bronchiectasis — end-stage Irreversible — no remission
Clinical Diagnosis Without Biopsy
Löfgren Syndrome — classical triad: bilateral hilar LAD + erythema nodosum + periarticular ankle arthritis/arthralgia. Diagnosed clinically; biopsy not required. Acute-onset, excellent prognosis, resolves spontaneously in most.
Heerfordt Syndrome (uveoparotid fever) — uveitis + parotid enlargement + facial nerve palsy ± fever. Highly characteristic, biopsy may be avoided if classic.
Asymptomatic bilateral hilar LAD in young adult — probability of sarcoidosis very high; biopsy still generally recommended to confirm.
Extrapulmonary Involvement to Screen
Eyes — uveitis (anterior/posterior); ophthalmic review in ALL patients regardless of symptoms
Heart — cardiac sarcoidosis; ECG (AV block, VT), Holter, cardiac MRI/PET if arrhythmia or conduction disease
Liver/Spleen — hepatosplenomegaly, cholestatic LFTs; ultrasound
Skin — erythema nodosum (acute), lupus pernio (chronic), violaceous plaques; biopsy accessible
Nervous system — cranial nerve palsies (esp. VII), meningitis, space-occupying lesions; MRI brain
Kidneys — nephrocalcinosis from hypercalcaemia; renal granulomas rare; check eGFR and urinary calcium
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Related Topics

Management

Sarcoidosis · Treatment

NOT ALL SARCOIDOSIS NEEDS TREATMENT — OBSERVE FIRST, TREAT WHEN INDICATED Many patients, especially Stage I/II, remit spontaneously. Treatment is indicated when disease is symptomatic, progressive, or involves critical organs (heart, eyes, CNS, kidneys).

Systemic corticosteroids remain the backbone of therapy; steroid-sparing agents reduce long-term steroid toxicity. There is no cure.
First question: Does this patient need treatment now, or can we observe?
OBSERVE (Watch & Wait)
1
Stage I asymptomaticBilateral hilar LAD only, no symptoms, normal PFTs — high chance of spontaneous remission. Observe with 3–6 monthly review.
2
Löfgren syndromeNSAIDs for arthralgia/erythema nodosum. Resolves spontaneously in most — systemic steroids rarely needed.
3
Stage II with mild/no symptomsMonitor PFTs, CXR, and symptoms every 3–6 months. Treat if progressive over 6–12 months.
4
Duration of observationUp to 6 months of watchful waiting is acceptable in stable, asymptomatic pulmonary sarcoidosis before initiating therapy.
TREAT (Systemic Therapy)
1
Symptomatic or progressive pulmonary diseaseWorsening dyspnoea, FVC decline ≥10%, or worsening HRCT despite observation.
2
Critical organ involvementCardiac (AV block, VT), neurosarcoidosis, sight-threatening uveitis, renal impairment, severe hypercalcaemia — treat without delay.
3
Start prednisolone0.5 mg/kg/day (20–40 mg/day) for 4–6 weeks, then gradual taper over 12 months. Most respond within weeks.
4
Add steroid-sparing agent earlyMethotrexate or azathioprine if prolonged steroids needed, relapse on taper, or steroid toxicity. Reduces cumulative steroid dose.
Drug / Treatment Line Dose / Notes
Prednisolone First-line 0.5 mg/kg/day (typically 20–40 mg/day). Taper after 4–6 weeks; minimum 12-month course. Use bone protection (calcium, vitamin D, bisphosphonates). Monitor glucose, BP, eyes (cataracts/glaucoma).
Methotrexate Steroid-sparing 7.5–15 mg/week orally + folic acid 5 mg once weekly (day after MTX). Most widely used second-line agent. Allows steroid dose reduction. Monitor FBC, LFTs monthly. Avoid in pregnancy.
Azathioprine Steroid-sparing 1–2 mg/kg/day. Check TPMT enzyme level before starting. Alternative to methotrexate. Monitor FBC and LFTs. Used in hepatic or neurological sarcoidosis.
Hydroxychloroquine Steroid-sparing 200–400 mg/day. Preferred for skin, hypercalcaemia, and constitutional symptoms (fatigue). Less effective for pulmonary disease. Annual retinal monitoring required (≥5 years of use).
Infliximab (anti-TNFα) Third-line / Refractory 3–5 mg/kg IV infusion at 0, 2, 6 weeks then every 4–8 weeks. Effective in refractory/chronic sarcoidosis. Screen for TB/hepatitis B before use. Best evidence for pulmonary and cutaneous disease.
Adalimumab Third-line / Refractory Subcutaneous anti-TNF; alternative to infliximab for refractory disease. Particularly used in ocular and cutaneous sarcoidosis.
Topical/Local Corticosteroids Organ-specific Topical eye drops (prednisolone/dexamethasone) for anterior uveitis — first-line before systemic. Inhaled corticosteroids for cough/bronchial sarcoidosis — limited systemic absorption.
NSAIDs Symptomatic For Löfgren syndrome arthralgia and erythema nodosum. Avoid systemic corticosteroids unless refractory in Löfgren. Short-course only.
ICD / Pacemaker Cardiac sarcoidosis Complete heart block → permanent pacemaker. Sustained VT/LVEF <35% → ICD. Systemic steroids for active cardiac inflammation (40 mg/day prednisolone). High mortality without treatment.
Lung Transplantation End-stage (Stage IV) For Stage IV pulmonary fibrosis with severe impairment. Sarcoidosis can recur in transplanted lungs (rare). Refer when FVC <50% or O2-dependent.
Monitoring on Treatment
Spirometry + DLCO — every 3–6 months during treatment
Serum ACE + calcium — useful markers of disease activity; normalise with response to therapy
CXR or HRCT — annually or if clinical change
Ophthalmic review — annually (steroid-induced cataracts/glaucoma + disease activity)
Steroid toxicity screen — bone density (DEXA), glucose, BP, weight at each visit
Minimum treatment duration — 12–18 months; relapse rate high if stopped earlier
Organ-Specific Treatment Priorities
Cardiac sarcoidosis — treat urgently; high-dose steroids + device therapy (PPM/ICD); cardiology and electrophysiology involvement
Neurosarcoidosis — high-dose IV methylprednisolone then oral taper; early add of methotrexate or infliximab; relapses common
Ocular sarcoidosis — topical steroids for anterior uveitis; systemic therapy for posterior/refractory uveitis; ophthalmology-led
Hypercalcaemia — hydration, low-calcium diet, hydroxychloroquine, steroids if severe; avoid sunlight (worsens via vitamin D activation)
Cutaneous sarcoidosis — topical steroids, hydroxychloroquine, methotrexate; infliximab for lupus pernio

Complications

  • Pulmonary fibrosis
  • Chronic respiratory failure
  • Pulmonary hypertension
  • Vision loss
  • Cardiac arrhythmias
  • Heart block
  • Heart failure
  • Sudden cardiac death
  • Neurological damage
  • Hypercalcemia
  • Kidney stones
  • Chronic organ dysfunction

Prognosis

  • The course is highly variable.
  • Many patients experience spontaneous remission.
  • Others develop chronic or progressive disease.
  • Prognosis is worse with:
    • Pulmonary fibrosis
    • Pulmonary hypertension
    • Cardiac involvement
    • Neurological involvement
    • Chronic progressive disease
  • Early recognition of serious organ involvement improves outcomes.

Key Points / Clinical Pearls

  • Sarcoidosis is a multisystem granulomatous disease.
  • The lungs and intrathoracic lymph nodes are most commonly affected.
  • Noncaseating granulomas are the pathological hallmark.
  • Bilateral hilar lymphadenopathy is a classic imaging finding.
  • Always exclude infections and other causes of granulomas.
  • Serum ACE does not confirm or exclude the diagnosis.
  • Not every patient requires treatment.
  • Corticosteroids are the main initial treatment for significant disease.
  • Always consider eye, cardiac, and neurological involvement.
  • National Heart, Lung, and Blood Institute (NIH). Sarcoidosis.
  • MedlinePlus, National Library of Medicine (NIH). Sarcoidosis: Medical Encyclopedia.
  • Crouser ED, Maier LA, Wilson KC, et al. Diagnosis and Detection of Sarcoidosis: An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. 2020. PMID: 32293205.