Erythema nodosum
Overview
Erythema nodosum is a condition that causes painful patches of skin that look red or darker than the surrounding skin. It usually goes away by itself, but it can sometimes be a sign of something serious like an inflammatory bowel condition, such as Crohn's disease.
Symptoms
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 temperaturehave swollen, aching joints, particularly the knees, ankles and wristsfeel generally unwell 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.
Causes
Erythema nodosum can be caused by lots of things, but often the cause is unknown. Common causes include: inflammatory bowel conditions likeCrohn's diseaseandulcerative colitisbacterial 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 thecontraceptive pilland some antibiotics
Treatment
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 givenantibiotics. 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 assteroid tablets, may be recommended.