Erythema nodosum

If you have erythema nodosum, you may have flu-like symptoms before or at the same time as you get the patches on your skin.

For example, you may:

• have a high temperature
• have swollen, aching joints, particularly the knees, ankles and wrists
• feel generally unwell

Large areas of skin are often red and tender or painful.

Erythema nodosum commonly affects the lower legs, but you can get it in other areas, such as on the arms, thighs and neck.

The affected patches of skin may heal and fade to leave marks that look like bruises.

The skin usually heals on its own within 3 to 8 weeks without leaving a scar. But other symptoms, such as joint pain and swelling, can last for several weeks.

There are some things you can do to help ease the pain of erythema nodosum.

• try taking ibuprofen – but if you have Crohn's disease or colitis, do not take ibuprofen or other anti-inflammatory painkillers unless your doctor tells you to

• rest with your feet raised on a pillow

• try to avoid long periods of standing, walking and running

• put a cool wet compress, like a damp cloth, on the affected area

If you're in pain, a pharmacist can recommend:

• stronger painkillers
• supportive bandages or stockings

They may also suggest you see a GP.

• you have a painful skin condition that affects your daily life
• lots of lumps or marks start appearing on your skin
• the lumps or marks do not go away after 8 weeks

The GP may be able to tell if you have erythema nodosum by looking at the inflamed areas of skin.

Tests may be needed to find the cause. This may include a biopsy, where a small sample of skin is taken so it can be looked at under a microscope.

Treatment for erythema nodosum depends on the cause.

If it's caused by another condition, treating that condition may help. For example, if it’s caused by an infection, you may be given antibiotics.

If the GP thinks a medicine you've been taking might be causing erythema nodosum, they may advise you to stop taking it. Do not stop taking medicines without asking a GP first.

If your symptoms have lasted a long time or they keep returning, other treatments, such as steroid tablets, may be recommended.

Erythema nodosum can be caused by lots of things, but often the cause is unknown.

Common causes include:

• inflammatory bowel conditions like Crohn's disease and ulcerative colitis
• bacterial infections, such a throat infection, chest infection or lung infection (tuberculosis)
• a rare condition where small patches of swollen tissue develop in organs, such as the lungs, lymph nodes or skin (sarcoidosis)
• a reaction to some medicines, including the contraceptive pill and some antibiotics

Erythema nodosum often affects the lower legs. Painful patches appear on the skin, which sometimes leave marks that look like bruises after healing.

Things you can do to ease the pain of erythema nodosum include taking ibuprofen, putting a cool cloth on your skin and raising your feet when resting.

A GP may be able to tell if you have erythema nodosum by looking at the affected areas of skin. A biopsy may be needed to find the cause.

Treatment for erythema nodosum depends on what’s causing it. If a medicine is thought to be the cause, a GP may advise you to stop taking it.

Causes of erythema nodosum include inflammatory bowel conditions and bacterial infections. Sometimes it can be caused by a reaction to a medicine.