Scadding staging
Overview
The Scadding staging system (1961) is the standard method for classifying intrathoracic Pulmonary sarcoidosis based on Chest Radiograph (CXR) findings.
Important: It is a radiographic staging system, not a clinical severity score.
Staging criteria & Prognosis
| Stage | Radiographic findings | Spontaneous resolution |
|---|---|---|
| Stage 0 | Normal chest radiograph (extranodal/extrapulmonary disease). | N/A |
| Stage I | Bilateral hilar lymphadenopathy (BHL) ± right paratracheal nodes. | 60–80% |
| Stage II | BHL + Pulmonary infiltrates (parenchymal disease). | 50–60% |
| Stage III | Pulmonary infiltrates without adenopathy (nodes have regressed). | <30% |
| Stage IV | Pulmonary fibrosis. Upper lobe volume loss, hilar retraction, honeycombing (rare). | 0% (Irreversible) |
Exam Pitfalls & Clinical Context
Critical Exam Trap: Stage
Scadding stage does not correlate with functional impairment.
- A patient with Stage IV (fibrosis) may be asymptomatic with stable PFTs ("burnt-out" disease).
- A patient with Stage II may have severe active alveolitis, profound hypoxia, and rapidly declining diffusion capacity (
). - Exam Tip: Never assume a higher stage equals "sicker" patient.
Progression logic
The stages generally progress from I
- Most present at Stage I or II.
- Stage III implies the lymphadenopathy has resolved while the parenchymal disease persists.
- Stage IV represents the end-stage fibrotic sequelae.
Associated Syndromes by Stage
- Stage I: Strongly associated with Löfgren syndrome (BHL + Erythema Nodosum + Arthralgia). High rate of spontaneous remission.
- Stage IV: Associated with Lupus pernio (chronic cutaneous sarcoid) and chronic uveitis.
