Erythema nodosum is a painful red nodular rash that may be a manifestation of numerous systemic diseases.
Erythema nodosum is three to five times more common in female patients 1.
Erythema nodosum appears as painful erythematous nodules over the shins approximately 1-6 cm in size and are usually distributed symmetrically. Systemic symptoms (e.g. fever) may also be present depending on the underlying condition 1.
The rash is caused by panniculitis (inflammation of the subcutaneous fat) and is thought to be due to a type IV hypersensitivity 1.
Multiple causes of erythema nodosum have been described 2:
- post-infectious (most common Streptococcal infection)
- infection (e.g. tuberculosis)
- pregnancy 3
- drug related (e.g. oral contraceptive pill)
- inflammatory bowel disease
- paraneoplastic syndromes (e.g. Hodgkin disease, leukemia)
Treatment and prognosis
Typically the lesions are self-limiting and resolve within a few weeks. Underlying disorders however should be investigated for and treated 1.
- 1. Schwartz RA, Nervi SJ. Erythema nodosum: a sign of systemic disease. (2007) American family physician. 75 (5): 695-700. Pubmed
- 2. Małgorzata Chowaniec, Aleksandra Starba, Piotr Wiland. Erythema nodosum – review of the literature. (2016) Reumatologia/Rheumatology. 54 (2): 79. doi:10.5114/reum.2016.60217 - Pubmed
- 3. Acosta KA, Haver MC, Kelly B. Etiology and therapeutic management of erythema nodosum during pregnancy: an update. (2013) American journal of clinical dermatology. 14 (3): 215-22. doi:10.1007/s40257-013-0024-x - Pubmed