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Erythema nodosum in Adult
Other Resources UpToDate PubMed

Erythema nodosum in Adult

Contributors: Andrina Mamo BS, Andrew Walls MD, Susan Burgin MD
Other Resources UpToDate PubMed

Synopsis

Erythema nodosum (EN) represents the most common type of septal panniculitis (inflammation of the subcutaneous fat). It represents a form of hypersensitivity reaction precipitated by infection, pregnancy, medications, connective tissue disease, or malignancy. Streptococcal infections are the most common etiologic factor in children. Sarcoidosis, inflammatory bowel disease (see Crohn disease, ulcerative colitis), and medications (particularly oral contraceptive pills) are more commonly implicated in adults. Often a cause or trigger is never found.

Associated bacterial, viral, fungal, and protozoal infections are numerous and include Streptococcus, Shigella, Yersinia, Histoplasma, Coccidioides, HIV, Giardia, and COVID-19. Tuberculosis (TB) remains an important cause in areas of endemic disease. Less commonly, Campylobacter, Salmonella, cat-scratch disease, Chlamydia, syphilis, pertussis, leprosy, hepatitis B, blastomycosis, and sporotrichosis may be precipitants. Inflammatory associations include sarcoidosis, inflammatory bowel disease, Sjögren syndrome, reactive arthritis, and Behçet disease. In Crohn disease, EN may occur even if the Crohn disease is well controlled. Malignancy, such as lymphoma or leukemia, is a rare cause of EN.

The eruption typically persists for 3-6 weeks and spontaneously regresses without scarring or atrophy. Recurrences are sometimes seen, especially with reoccurrence of the precipitating factor(s).

Arthralgias, often in the ankles and knees, are reported by a majority of patients, regardless of the etiology of EN.

No specific genetic predilection exists except for in relation to the underlying diseases (eg, sarcoidosis is more common in Black individuals). EN can occur at any age, but most cases occur between the ages of 20 and 45, particularly in women. Sex incidence before puberty is about equal.

Löfgren syndrome is a benign variant of sarcoidosis with EN and bilateral enlargement of the hilar lymph nodes. It occurs more commonly in females, especially during pregnancy.

Subacute nodular migratory panniculitis is a variant of EN. It is often unilateral, more focal, and painless. Gradual expansion is characteristic.

Codes

ICD10CM:
L52 – Erythema nodosum

SNOMEDCT:
32861005 – Erythema nodosum

Look For

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

Other forms of panniculitis:
  • Nodular vasculitis / erythema induratum is typically on the posterior calves.
  • Primary infectious panniculitis (see panniculitis) occurs through septic seeding or direct inoculation of a variety of infectious organisms. Tissue culture and polymerase chain reaction (PCR) aids in diagnosis.
  • Pancreatic panniculitis favors the lower legs but is often ulcerated.
  • Lupus panniculitis favors the face and upper trunk. Most cases are not associated with systemic lupus erythematosus.
  • Panniculitis of dermatomyositis (abdomen, thighs, arms) may be the first manifestation of dermatomyositis.
  • Granulomatous panniculitis is a manifestation of subcutaneous granuloma annulare or sarcoidosis.
  • Cold panniculitis typically presents on the cheeks in children. In adults, it may occur on any body site exposed to cold temperatures. Lateral thigh involvement of horseback riders has been described.
  • Injections, including iatrogenic and factitial.
  • Alpha-1 antitrypsin deficiency panniculitis is extremely rare in children but has been reported as an initial manifestation of the disease. Lesions frequently ulcerate.
  • Subcutaneous T-cell lymphoma
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Therapy

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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References

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Last Reviewed:06/26/2022
Last Updated:07/02/2022
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Erythema nodosum in Adult
A medical illustration showing key findings of Erythema nodosum (Adult) : Arthralgia, Smooth nodules, Smooth plaques
Clinical image of Erythema nodosum - imageId=2299356. Click to open in gallery.  caption: 'Many erythematous and ecchymotic plaques of varying sizes on the lower legs.'
Many erythematous and ecchymotic plaques of varying sizes on the lower legs.
Copyright © 2022 VisualDx®. All rights reserved.