Löfgren syndrome
Overview
A specific, acute clinical presentation of Pulmonary sarcoidosis. It is distinct due to its highly specific clinical triad and excellent prognosis.
- Epidemiology: Classically described in Scandinavian/Northern European females, but occurs globally.
- Prognosis: Excellent. >90% spontaneous resolution within 3–6 months. NSAIDs are usually sufficient for management.
The Clinical Triad
Diagnosis is often clinical + radiographic. Biopsy is frequently not required if the classic triad is present.
- Bilateral hilar lymphadenopathy (BHL)
- Usually massive and symmetric.
- Corresponds to Scadding Stage I.
- Erythema nodosum
- Painful, tender, erythematous nodules on the anterior shins.
- Note: More common in women.
- Arthralgia / Arthritis
- Oligoarticular, predominantly affecting the ankles (bilateral ankle arthritis/periarthritis).
- Can mimic cellulitis due to periarticular inflammation.
Imaging Findings
Chest Radiograph (CXR)
- Essential Finding: Bilateral hilar lymphadenopathy (BHL).
- Paratracheal Nodes: Right paratracheal stripe widening is common (part of the 1-2-3 sign).
- Lung Fields: Typically clear (Stage I).
MRI Ankle (if performed)
- Usually not indicated, but if done for "ankle pain":
- Periarthritis: Soft tissue oedema surrounding the joint capsule and tendons (tenosynovitis) is more prominent than actual intra-articular synovitis.
- No erosions (unlike Rheumatoid arthritis).
Exam Pearls & Management
The "Don't Touch" Lesion
In the presence of the classic triad (BHL + Erythema Nodosum + Arthritis), the specificity for sarcoidosis is ~95%.
- RCR/BTS Guidelines: Transbronchial or EBUS biopsy is NOT routinely indicated.
- Management: Observation + NSAIDs. Corticosteroids only for severe symptoms.
Thai Board Context: The TB Trap
While Löfgren syndrome is a classic "exam anchor," in actual Thai practice, Tuberculosis remains the primary differential for BHL + fever/arthralgia (Poncet's disease).
- If the patient has constitutional symptoms (weight loss, night sweats) or if the BHL is asymmetric/necrotic on CT, assume TB until proven otherwise.
