Erythema Nodosum
Condition
Definition
Erythema nodosum is a rare condition where tender lumps form on the skin. It is due to inflammation of fat or connective tissue beneath the skin.
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Causes
Erythema nodosum may be caused by:
- Infections due to:
- Viruses
- Bacteria, especially strep throat
- Fungi
- Inflammatory conditions such as:
- Pregnancy
- Medicines such as:
- Birth control pills
- Sulfa drugs and some other antibiotics
- Iodides
- Bromides
- Leukotriene modifiers
- Proton pump inhibitors
- Certain types of cancer, such as:
- Lymphoma
- Leukemia
Sometimes the cause is not known.
Risk Factors
This condition is more common in females and young adults aged 20 to 30 years old.
The risk of this problem is low. It is only slightly higher in those who have the causes listed above.
Symptoms
Symptoms start suddenly. A person may have:
- Very tender, deep lumps, like bruises, that:
- Change color from pink to blue to brown
- Are often found on the shins
- May also appear on the arms, trunk, neck, and head
- Flu-like symptoms and joint pain—these can also appear one to three weeks before the lumps
Diagnosis
The doctor will ask about symptoms and health history. A physical exam will be done. This may be enough to diagnose the problem.
Tests may be done to look for a cause. They may be:
- Blood and urine tests
- Cultures or a throat swab for strep
- PPD skin test for tuberculosis
- Biopsy of one of the skin lumps
- Chest x-rays
Treatment
The goal of treatment is to manage symptoms and treat any underlying causes. The lumps tend to go away on their own. This may take up to six weeks.
Pain can be eased with:
- Bed rest and elevation of legs
- Wet compresses
- Aspirin—Note: children should not have aspirin or aspirin products, as it may cause serious problems
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Potassium iodide
If symptoms are severe, other medicines may be given, such as steroids.
Prevention
There are no known guidelines for preventing this condition.
American Academy of Dermatology
Family Doctor—American Academy of Family Physicians
CANADIAN RESOURCES:
Canadian Dermatology Association
Health Canada
American Academy of Dermatology
Family Doctor—American Academy of Family Physicians
CANADIAN RESOURCES:
Canadian Dermatology Association
Health Canada
References
- Erythema nodosum. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/erythema-nodosum.
- Erythema nodosum. DermNet New Zealand website. Available at: https://www.dermnetnz.org/topics/erythema-nodosum.
- Erythema nodosum. Better Health Channel website. Available at: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/erythema-nodosum.
- Leung, A.K.C., Leong, K.F., et al. Erythema nodosum. World Journal of Pediatrics, 2018; 14 (6): 548-554.
Contributors
- Mary-Beth Seymour, RN
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