About Erythema Nodosum

Erythema nodosum (EN) is an acute, nodular, erythematous eruption that usually is limited to the extensor aspects of the lower legs. Chronic or recurrent EN is rare but may occur. EN is presumed to be a hypersensitivity reaction and may occur in association with several systemic diseases or drug therapies, or it may be idiopathic. The inflammatory reaction occurs in the panniculus.

 

EN probably is a delayed hypersensitivity reaction to a variety of antigens; circulating immune complexes have not been found in idiopathic or uncomplicated cases, however they may be demonstrated in patients with inflammatory bowel disease.

 

Frequency:
In the US: Peak incidence occurs at age 18-34 years.
Age and sex distributions vary according to etiology and geographic location.

Internationally: Rates of EN vary according to country.
In England, the rate is 2.4 cases per 10,000 per year.

Mortality/Morbidity: In most patients, EN resolves without any adverse reactions.

Sex: Women are affected more often than men, with a male-to-female ratio of 1:4.

Age: EN may occur in children and in patients older than 70 years, but it is more common in young adults aged 18-34 years.
Age distribution varies with geographic location and etiology.
 

History:

The eruptive phase of EN begins with flulike symptoms of fever and generalized aching. Arthralgia may occur and precedes the eruption or appears during the eruptive phase. Most lesions in infection-induced EN heal within 7 weeks, but active disease may last up to 18 weeks. In contrast, 30% of idiopathic EN cases may last more than 6 months. Febrile illness with dermatologic findings includes abrupt onset of illness with initial fever, followed by a painful rash within 1-2 days

 

Physical:
Pertinent physical findings are limited to the skin and joints.


Primary skin lesions:

Lesions begin as red tender nodules (see Picture 1). Lesion borders are poorly defined, and lesions vary from 2-6 cm. During the first week, lesions become tense, hard, and painful; during the second week, they may become fluctuant, as in an abscess, but do not suppurate or ulcerate. Individual lesions last approximately 2 weeks, but occasionally, new lesions continue to appear for 3-6 weeks. Aching legs and swelling ankles may persist for weeks.


Distribution of skin lesions:

Characteristically, lesions appear on the anterior leg; however, they may appear on any surface.

Color of skin lesions:

Lesions change color in the second week from bright red to bluish or livid. As absorption progresses, the color gradually fades to a yellowish hue, resembling a bruise. This disappears in 1 or 2 weeks as the overlying skin desquamates.

Hilar lymph nodes:

Hilar adenopathy may develop as part of the hypersensitivity reaction of EN. Bilateral hilar lymphadenopathy is associated with sarcoidosis, while unilateral changes may occur with infections and malignancy.

Joints:

Arthralgia occurs in more than 50% of patients and begins during the eruptive phase or precedes the eruption by 2-4 weeks. Erythema, swelling, and tenderness occur over the joint, sometimes with effusions. Joint tenderness and morning stiffness may occur. Any joint may be involved, but the ankles, knees, and wrist are affected most commonly. Synovitis resolves within a few weeks, but joint pain and stiffness may last up to 6 months. No destructive joint changes occur. Synovial fluid is acellular, and the rheumatoid factor is negative.

 

Causes:

Currently, the most common cause of EN is streptococcal infection in children and streptococcal infection and sarcoidosis in adults. Numerous other causes have been reported.

The causes reported most often in the literature are as follows:

Bacterial infections include the following 
Streptococcal infections: These infections are one of the most common causes of EN.
Tuberculosis: An important cause in the past, tuberculosis has decreased dramatically as a cause for EN but still must be excluded.
Yersinia enterocolitica: This gram-negative bacillus causes acute diarrhea and abdominal pain and is a common cause of EN in France and Finland. Mycoplasma pneumoniae infection may cause EN.
Leprosy: Clinically, erythema nodosum leprosum resembles EN, but the histologic picture is that of leukocytoclastic vasculitis.
Lymphogranuloma venereum may cause EN.
Salmonella infection may cause EN.
Campylobacter infection may cause EN.
 

 


For More Information, Click the GoodSearch Logo and 
Search for Erythema Nodosum.
GoodSearch: You Search...We Give!
Every time you use the GoodSearch as your Search Engine, a penny will be donated to the Erythema Nodosum Research Fund.

 

We have a very active on line support group.

Click here for an invitation to join the group.

Visit Our Erythema Nodosum Support Group Here!

An Invitation For Your Doctor

 

Find out how you can help find a cure for EN Here.

 
Main Index Page

 
Tell a friend about this site:
Home Page EN Information EN Triggers
Pictures Panniculitis Information Auto-Immune Info
EN Articles And Current Treatments Links   EN Related Disorders And Other Health Info Links
Support Groups "Friends Of EN" About Rebecca
     
     
Sign Our Guest Book View Our Guest Book Guest Book Archives.

 

Free DHTML scripts provided by
Dynamic Drive