Erythema nodosum: symptoms and most frequent causes

Erythema nodosum is a skin lesion that presents red and tender bumps, commonly on the shins; know the symptoms associated with this skin lesion. Click To Tweet

Erythema nodosum is swollen fat under the skin, causing bumps and patches that look red or darker than the surrounding skin. These bumps can be slightly tender to the touch and are usually found symmetrically on the shins. The John Hopkins University characterises that up to 55 per cent of cases have no identifiable cause. Rather, it is a sign of infection, disease, or sensitivity to a drug.

Erythema nodosum is often a sign of other health concerns. So it’s important to understand the symptoms and most frequent causes of this condition. Early detection helps to address the core issue and find the correct resolution to ease this condition. 


Symptoms of erythema nodosum vary in intensity and timescale. Development of erythema nodosum can occur in a short timescale and more prolonged, depending on the original cause and the severity of the reaction. The lesions typically appear on the lower leg.

The main signs and symptoms of erythema nodosum are the following: 

  • Tender bumps with a reddish tone
  • Bumps can measure between 1 cm and 5 cm
  • A high temperature
  • Tiredness
  • Joint and muscle pain.

The bumps usually heal on their own within 3 to 8 weeks without leaving a scar. But other symptoms, such as joint pain, may last several weeks or months.

Erythema nodosum: symptoms and most frequent causes


The cause of erythema nodosum is unknown, but certain drugs, diseases, and infections can trigger the condition. However, the trigger remains unknown. Even with treatment, the inflamed nodules can take around 3 to 6 weeks to resolve. Some of the most common reasons for erythema nodosum are:

Infections and diseases:

  • Crohn’s disease
  • Ulcerative colitis
  • Sarcoidosis
  • Tuberculosis
  • Pneumonia
  • A throat infection
  • A fungal infection.


  • Antibiotics containing sulfa or penicillin
  • Bromides
  • Iodides 
  • Oral contraceptives.

Whatever the cause, if you’re experiencing symptoms of erythema nodosum, contact your doctor so that tests can be performed to figure out the cause of this reaction and you can receive the correct treatment plan. Often blood tests will be conducted, so if you’re in need, book here


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