Erythema Nodosum

Erythema nodosum is most common in people in their 20s and 30s, especially women

It's usually caused by a reaction to a medicine or an infection

In addition to the bumps on your skin, you may have fever and joint pain

It usually gets better on its own in 3 to 6 weeks

Infections, including streptococcal infections Streptococcal Infections What are streptococcal infections? Streptococcus, simply called strep, is a common group of bacteria. Different types of strep cause different diseases. Most often they cause sore throat or... read more

Sarcoidosis Sarcoidosis Sarcoidosis is a disease in which small clumps of inflammatory cells form in one or more of your organs. The clumps of cells are called granulomas. They aren't cancerous. When you have sarcoidosis... read more (a disease that causes small clumps of immune cells to grow in many of your organs)

Inflammatory bowel disease Overview of Inflammatory Bowel Disease (IBD) In inflammatory bowel diseases, the intestine (bowel) becomes inflamed, often causing recurring abdominal pain and diarrhea. The two primary types of inflammatory bowel disease (IBD) are Crohn... read more

Certain medicines, including antibiotics and birth control pills

Pregnancy

Tuberculosis Tuberculosis (TB) Tuberculosis (TB) is a common, serious infection caused by bacteria called Mycobacterium tuberculosis. TB affects millions of people worldwide, particularly in low-resource countries... read more

Behçet disease Behçet Disease Behçet disease is chronic blood vessel inflammation (vasculitis) that can cause painful mouth and genital sores, skin lesions, and eye problems. The joints, nervous system, and digestive tract... read more —a long-term inflammation (swelling) of blood vessels that can cause painful mouth and genital sores, skin blisters, and sometimes problems with your eyes, joints, or organs

Certain cancers

Painful, red or purple bumps, usually on your shins

Fever

Joint pain

Chest x-ray

Blood tests

Skin test for tuberculosis Tuberculosis (TB) Tuberculosis (TB) is a common, serious infection caused by bacteria called Mycobacterium tuberculosis. TB affects millions of people worldwide, particularly in low-resource countries... read more

Bed rest

Cool compresses

Keeping your leg elevated

Taking nonsteroidal anti-inflammatory drugs (NSAIDs—such as aspirin or ibuprofen)

Sometimes, your doctor may have you take potassium iodide to help with symptoms

Sometimes, corticosteroids (medicines to lower swelling)