Merck Manual

Please confirm that you are not located inside the Russian Federation

Yes No

Leave this Site?

The link you have selected will take you to a third-party website. We do not control or have responsibility for the content of any third-party site.

Continue Cancel
honeypot link
Merck Manual
Consumer Version
The trusted provider of medical information since 1899
Health Topics & Chapters
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Home /
Quick Facts: Skin Disorders /
Hypersensitivity and Inflammatory Skin Disorders /
... /
Erythema Nodosum /
IN THIS TOPIC

What is erythema nodosum?

What causes erythema nodosum?

What are the symptoms of erythema nodosum?

How can doctors tell if I have erythema nodosum?

How do doctors treat erythema nodosum?

OTHER TOPICS IN THIS CHAPTER

Hypersensitivity and Inflammatory Skin Disorders

ADDITIONAL CONTENT

Test your knowledge

Orbital Cellulitis
Which form of treatment may be necessary for orbital cellulitis but not for preseptal cellulitis? 
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

More Content

Quick Facts

Erythema Nodosum

By

The Manual's Editorial Staff

Last full review/revision Jan 2021| Content last modified Jan 2021
Click here for the Professional Version
Get the full details
Topic Resources

What is erythema nodosum?

"Erythema" means red-colored. "Nodosum" means nodules (lumps or bumps).   

Erythema nodosum is an inflammatory reaction in the layer of fat under your skin. It causes red or purplish bumps under your skin, often on your shins.

  • Erythema nodosum is most common in people in their 20s and 30s, especially women

  • It's usually caused by a reaction to a medicine or an infection

  • In addition to the bumps on your skin, you may have fever and joint pain

  • It usually gets better on its own in 3 to 6 weeks

What causes erythema nodosum?

Common causes include:

Less common causes:

  • Certain medicines, including antibiotics and birth control pills

  • Pregnancy

  • Tuberculosis

  • Behçet disease—a long-term inflammation (swelling) of blood vessels that can cause painful mouth and genital sores, skin blisters, and sometimes problems with your eyes, joints, or organs

  • Certain cancers

What are the symptoms of erythema nodosum?

Symptoms include:

  • Painful, red or purple bumps, usually on your shins

  • Fever

  • Joint pain

How can doctors tell if I have erythema nodosum?

Doctors can usually tell you have erythema nodosum by looking at the bumps on your skin. Sometimes to know for sure they'll do a biopsy (take out a small piece of tissue to look at under a microscope).

To find out what's causing your erythema nodosum, they may do other tests, such as:

How do doctors treat erythema nodosum?

Erythema nodosum gets better on its own after 3 to 6 weeks. If your erythema nodosum is caused by an infection, doctors will treat the infection. The following may help you lessen pain:

  • Bed rest

  • Cool compresses

  • Keeping your leg elevated

  • Taking nonsteroidal anti-inflammatory drugs (NSAIDs—such as aspirin or ibuprofen)

  • Sometimes, your doctor may have you take potassium iodide to help with symptoms

  • Sometimes, corticosteroids (medicines to lower swelling)

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
© 2020 Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA)
Erythema Multiforme
Granuloma Annulare
Others also read
Erythema Nodosum Erythema Nodosum
Sarcoidosis Sarcoidosis
Behçet Disease Behçet Disease

Also of Interest

SOCIAL MEDIA

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Merck and the Merck Manuals

Merck & Co., Inc., Kenilworth, NJ, USA is a global healthcare leader working to help the world be well. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world. The Merck Manual was first published in 1899 as a service to the community. The legacy of this great resource continues as the Merck Manual in the US and Canada and the MSD Manual outside of North America. Learn more about our commitment to Global Medical Knowledge.

View Privacy Shield Verification Status
View APEC CBPR Privacy Certification Status

This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.

© 2021 Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA
TOP