Erythema Nodosum

Description

Erythema nodosum is the most common form of septal panniculitis and is characterized by the rapid appearance of one or more painful, erythematous nodules, most commonly on the anterior surfaces of the lower legs. Panniculitis is an inflammatory disorder of the subcutaneous adipose tissue that is often accompanied by episodes of fever, malaise, and tender subcutaneous nodules.

Erythema nodosum is an acute inflammatory condition that most commonly affects women between 20 and 30 years of age, although it can occur at any age, including in children. It may be associated with:

a) infectious diseases (streptococcal pharyngitis, tuberculosis, salmonellosis, etc.);

b) medications (penicillin, sulfonamides, oral contraceptives);

c) systemic diseases (sarcoidosis, inflammatory bowel disease, systemic lupus erythematosus, dermatomyositis, systemic sclerosis, and malignancy).

Symptoms

Several weeks before the appearance of painful erythematous nodules, patients may experience fever, malaise, and arthralgia. The nodules most commonly develop on the anterior surfaces of the lower legs. Deeper nodules may be palpable but not readily visible. Within several days to two weeks, the nodules gradually change in color, resembling resolving bruises. They usually resolve completely within 4–6 weeks without scarring. Ulceration is very rare.

Chronic erythema nodosum may recur over several years. It is most commonly seen in middle-aged women, who often have underlying conditions that predispose them to the disorder.

Diagnosis

The diagnosis is based primarily on the clinical presentation, although a skin biopsy may be performed when the diagnosis is uncertain. Patients may undergo chest radiography and a tuberculin skin test (Mantoux test) if tuberculosis is suspected. A throat swab or throat culture may be performed to detect streptococcal infection. When pancreatic disease is suspected, serum amylase, lipase, and alpha-1 antitrypsin levels may be measured.

Treatment

The underlying cause of erythema nodosum should be identified and treated whenever possible. Acute erythema nodosum is usually self-limiting and often resolves without specific therapy. Patients are advised to rest, elevate the affected legs, and use aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and fever. Chronic or recurrent erythema nodosum may be treated with potassium iodide, corticosteroids, colchicine, immunosuppressive agents such as azathioprine or cyclosporine, or intralesional triamcinolone injections. If no underlying cause is identified, symptomatic treatment is recommended.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology