From the Guidelines
The workup for erythema nodosum should begin with a thorough history and physical examination, focusing on identifying potential triggers, as diagnosis is typically made on clinical grounds 1. The initial evaluation should include a comprehensive medical history to identify potential underlying causes, such as infections, medications, or inflammatory conditions.
Key Components of the Workup
- Laboratory tests, including complete blood count, erythrocyte sedimentation rate, and C-reactive protein, to assess for inflammation and potential underlying infections 1
- Chest X-ray to evaluate for sarcoidosis or tuberculosis, which can be associated with erythema nodosum 1
- Additional tests, such as throat culture, stool studies for enteric pathogens, and pregnancy test in women of childbearing age, may be considered based on the clinical presentation 1
Treatment Approach
- Treatment focuses on addressing the underlying cause while providing symptomatic relief with NSAIDs, such as ibuprofen or naproxen, and elevation of affected limbs to reduce edema 1
- For severe cases, systemic corticosteroids, like prednisone, may be considered, and colchicine can be used for recurrent cases 1
- Identifying and treating the underlying cause is crucial for preventing recurrence, and common triggers include streptococcal infections, medications, inflammatory bowel disease, sarcoidosis, and tuberculosis 1
From the Research
Erythema Nodosum Workup
The workup for erythema nodosum involves a comprehensive approach to identify the underlying cause of the condition. The following steps are recommended:
- Comprehensive history and physical examination to identify potential underlying conditions 2
- Complete blood count with differential 2
- Erythrocyte sedimentation rate, C-reactive protein level, or both 2
- Testing for streptococcal infection (i.e., throat culture, rapid antigen test, antistreptoly-sin-O titer, and polymerase chain reaction assay) 2
- Biopsy to confirm the diagnosis and rule out other conditions 2
- Purified protein derivative test and chest radiography to rule out tuberculosis 2
- Stool cultures and other tests as needed to rule out other underlying conditions 2
Diagnostic Algorithm
A diagnostic algorithm can be used to optimize the initial workup and initiate prompt and accurate management of the underlying disease 3. The algorithm includes:
- Initial assessment of core symptoms
- Diagnostic workup
- Differential diagnosis
- Recommended therapies
Underlying Conditions
Erythema nodosum can be associated with a variety of underlying conditions, including:
- Infections (e.g., streptococcal, tuberculosis, Mycoplasma, Bartonella) 4, 2, 3
- Inflammatory diseases (e.g., sarcoidosis, Behçet disease, inflammatory bowel disease) 4, 2, 3
- Neoplasia 4, 2, 3
- Drugs 4, 2, 3
- Pregnancy 3
Treatment
Treatment of erythema nodosum should be directed at the underlying cause, if identified 5, 3. Symptomatic treatment options include: