context: If your breast looks red or swollen, there's no need to panic. A tender area or rash on your breast often signals a common problem like an infection. Rarely, a rash and soreness can be signs of inflammatory breast cancer, a form of the disease that grows quickly, often in weeks or months. Here's how to tell the difference. Also called mastitis, infected breast tissue is most common in women who are nursing. It can happen when milk gets trapped in your breast. You might also get it if one of your milk ducts is clogged or bacteria get into your breast through a cracked nipple. Mastitis often happens within the first 6 to 12 weeks after you give birth, but sometimes women who aren't breastfeeding get it, too. If you have mastitis, your symptoms may come on without warning. Common signs include: Tender, warm, or swollen breasts A red patch of skin, often in a wedge shape Pain or burning when you breastfeed A fever of 101 F or higher Chills Inflammatory breast cancer symptoms result from a buildup of fluid in your breast. Many women don't feel a lump. Instead, you may notice: Itching that doesn't go away A rash that may look like an insect bite Your nipple turns inward or gets flat Swelling and redness that affects at least 1/3 of your breast Pink, purple-red, or bruised skin Skin that looks ridged or pitted like an orange peel A sudden increase in breast size Breast tenderness or a âheavyâ feeling Swollen lymph nodes under your arm or near your collarbone Mastitis and inflammatory breast cancer aren't the only health issues that can cause your breast to feel or look different. Paget's disease is a rare skin disorder that's often linked to breast cancer in the tissues behind your nipple. It can cause a red, scaly rash. You could also have discharge or bleeding from your nipple. Many benign (not cancerous) conditions could cause sore breasts, like: Intertrigo. It happens when the skin under your breast rubs together too much. It can trap moisture and create friction. Besides a red or brown rash, your skin may swell and itch. It may have a funny smell. Nipple eczema. It can lead to a rash around one or both of your nipples. The skin around them may get dry and scaly, or you could have a rash that feels moist to the touch. You may notice a burning feeling if you're nursing. Nipple eczema often affects women about 5 to 6 months after giving birth. A breast rash can also result from common skin problems that could happen anywhere on your body. This includes: Hives : Red, itchy welts on your skin that often result from an allergy Psoriasis : Scaly, itchy patches of skin that show up when your immune system goes haywire and attacks your body Scabies : Bites from the human itch mite. They form a line of little bumps on your skin and get really itchy at night Shingles : Painful, itchy blisters that result from the same virus that causes chickenpox Yeast: This fungus lives on your skin. When too much grows, it can lead to an itchy rash in places where skin touches skin. If you notice a change in your breasts, try not to worry. Because the hormones in your body are constantly changing, so are your breasts. Many of these differences aren't cause for concern. It can help to: Avoid scratching. This will only make your rash worse. Take a warm bath or place a warm washcloth over your breast. This may help soothe your skin. Look for a cause. Did you try a new perfume or laundry detergent? Stop using any recently added products and see if your rash improves. Signs that you should call your doctor right away include: Fever Intense pain Red streaks coming from your breast Yellow or green pus Open sores You should also see your doctor if any symptoms get worse. They'll do an exam to figure out what's causing your rash so they can prescribe the best treatment. Some simple rashes go away quickly with a special cream. If you do have a breast infection, you'll need antibiotics. Make sure you finish all your medicine, even if you start feeling better right away. Unless your doctor suggests otherwise, you won't need to stop nursing. Try to fully empty your breasts so you're less likely to get an abscess -- a pocket of pus that may need to be drained. Drink plenty of fluids and get lots of rest to help your body fight off a breast infection. Since the symptoms of inflammatory breast cancer and a breast infection can overlap, your doctor may want you to get a mammogram. This can give your doctor a better idea of what's going on inside your breast. If your symptoms don't clear up soon, your doctor may also want to do a biopsy. They'll remove a small piece of your breast tissue and look closely at it under a microscope. Catching inflammatory breast cancer early will help you get the treatment you need right away.