Erythema Nodosum: Associated Conditions
Erythema nodosum is observed in sarcoidosis (a), Mycoplasma infection (c), and seronegative spondyloarthritis (d), but not in leishmaniasis or multiple myeloma.
Confirmed Associations
Sarcoidosis
- Erythema nodosum occurs in approximately 85% of sarcoidosis patients presenting with acute arthritis and has an excellent prognosis, with spontaneous remission in the vast majority of cases. 1
- Löfgren's syndrome, defined as bilateral hilar adenopathy with erythema nodosum and/or periarticular arthritis, is a highly probable clinical feature supporting sarcoidosis diagnosis 1
- Erythema nodosum associated with sarcoidosis may respond to hydroxychloroquine in addition to standard therapy 2
Mycoplasma Infection
- Erythema nodosum is a recognized cutaneous manifestation triggered by infectious processes, including atypical bacterial infections such as Mycoplasma 3, 4
- The disorder represents a hypersensitivity response to various antigenic stimuli, with infections being among the most common identifiable causes 5, 6
Seronegative Spondyloarthropathies
- Erythema nodosum is a recognized extraarticular manifestation of the spondyloarthropathies, which include ankylosing spondylitis, psoriatic arthritis, and inflammatory bowel disease-associated arthritis 1
- These conditions share common features including inflammatory arthritis, enthesitis, and associations with inflammatory bowel disease 1
- Psoriatic arthritis is specifically classified as a member of the seronegative spondyloarthropathies 1
Conditions NOT Associated
Leishmaniasis
- Leishmaniasis is not listed among the infectious causes of erythema nodosum in comprehensive reviews 3, 4, 5
- The typical infectious triggers include streptococcal pharyngitis, tuberculosis, deep fungal infections (coccidioidomycosis, histoplasmosis), but not parasitic infections like leishmaniasis 2, 4, 5
Multiple Myeloma
- While malignancies can rarely be associated with erythema nodosum, the specific association is primarily with lymphomas (Hodgkin's and non-Hodgkin's disease), not multiple myeloma 7
- Multiple myeloma is not mentioned as a cause in any of the comprehensive reviews of erythema nodosum etiology 3, 4, 5
Clinical Context
Erythema nodosum manifests as tender, erythematous, subcutaneous nodules measuring 1-5 cm in diameter, typically bilateral and symmetrical on the anterior tibial areas 8, 2, 3
The most common identifiable causes include:
- Streptococcal infections (most frequent) 4, 5
- Primary tuberculosis 4, 5
- Sarcoidosis 1, 4, 5
- Behçet disease 2, 4
- Inflammatory bowel disease (4.2-7.5% of IBD patients) 8, 2
- Drugs (oral contraceptives, sulfonamides, halides) 4, 6
- Pregnancy 3, 4
Approximately 50% of cases remain idiopathic despite thorough evaluation 5, 6