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Rash Under Your Breasts: What You Need to Know

Do you have redness, itching, or painful lesions under one or both breasts? These could be manifestations of a rash. Learn about some common reasons you might have an underboob rash, the types of rash under breasts, and different rash under breast treatment options.

Causes of rash under the breasts

A rash under the breasts can be quite uncomfortable. An under-breast rash can cause symptoms of itching, swelling, dryness, and even wounds or open sores. There are different causes of breast rash, including inflammation, allergic reaction, chronic skin conditions, or fungus under the breast. Here’s more about the different kinds of rash under the breasts. 

Skin folds

A common reason for rash under breasts is intertrigo, which is inflammation of the skin where it folds. Two skin surfaces rubbing together, combined with heat, moisture, or a lack of air circulation, can lead to the development of a rash. 

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A skin fold rash under the breast can cause itching, burning, pain, and stinging. If left untreated, the rash can lead to open wounds or infection. If you’re overweight or have diabetes, you may be more at risk of experiencing intertrigo.

There are ways to prevent skin fold rashes, including weight loss, glucose control (if the rash under the breasts is related to diabetes) and good daily hygiene. Treatment options include using a drying agent to reduce moisture in the area, combined with antimicrobial or antifungal creams or ointments to reduce the presence of microorganisms.

Dry your skin thoroughly after washing and wear a well-fitting, supportive bra to reduce friction and movement of the area.

Heat Rash

Another form of an underboob rash could be heat rash, also known as miliaria. Heat rash under the breasts is caused by abnormal sweat gland function, which can happen in climates with high heat or humidity. It occurs when the sweat glands become blocked and sweat leaks into the surrounding skin tissues. 

Heat rashes can also occur from excessive sweating, for example, if you’re doing strenuous exercise.

You can prevent heat rash by wearing lightweight and breathable clothing, especially in hot and humid temperatures, and avoiding excessive UV exposure. Heat rashes can also occur from excessive sweating, for example, if you’re doing strenuous exercise. 

If you have a heat rash, you can usually treat it with lotions that have calamine, boric acid, or menthol ingredients. Cool the area with a wet compress and allow it to dry. Take frequent showers to help unblock the sweat ducts.

Exposure Rash

If you experience a rash shortly after coming in contact with a particular substance, it’s possible you have contact dermatitis. An exposure rash is how your immune system protects the skin from coming into contact with something it recognizes as harmful. You may have experienced contact dermatitis due to an allergic reaction to poison ivy, materials like latex or nickel, or chemicals found in cleaning products. 

Check your skin regularly if you’ve had an allergic reaction and get medical treatment if the rash spreads quickly.

Exposure rashes can cause itching, burning, and sometimes blistering. If you have an itchy rash under your breasts after trying a new skincare cream, this could be an example of an allergic reaction to one of the ingredients. 

If you’re having an episode of contact dermatitis, try to identify the source and avoid it in the future. Check your skin regularly if you’ve had an allergic reaction and get medical treatment if the rash spreads quickly. 

Reaction to medication

Some prescription medications and over-the-counter drugs, including certain antibiotics and diuretics, can cause side effects such as a rash. Certain drugs can even create a rash if you’re exposed to sunlight while you’re taking them. 

A drug rash usually starts with a small cluster of red spots that gradually spread and merge. If you stop taking the drugs, the rash will clear up within a few days or weeks. 

Some prescription medications and over-the-counter drugs, including certain antibiotics and diuretics, can cause side effects such as a rash.

In more severe circumstances, the allergic reaction can be quite serious. An allergic reaction to medication can be life-threatening if it covers large areas of the skin, or affects your respiratory system or other organs. Seek urgent medical care if you experience these symptoms.

Speak with your pharmacist about side effects before taking any drugs and follow the instructions provided for dosage and drug warnings.


People who have eczema have typically had it for most of their lives. Eczema is a chronic skin disease that usually causes dry rashes on the face and neck. Sometimes, eczema pops up around your breasts, either as a rash between the breasts or under the breasts. Allergic reactions and asthma are also sometimes associated with eczema outbreaks. 

Depending on the severity of your eczema outbreak, your dermatologist may recommend moisturizing the area or prescribe specific medications or steroid creams.


Another possible cause of red rash under your breasts is psoriasis. Like eczema, psoriasis is a chronic inflammatory skin disease. Psoriasis creates a sudden buildup of rough, scaly skin with thick, scale-like patches that are red, itchy, and sometimes painful.

Psoriasis symptoms can range from an occasional small rash to a rather debilitating rash. Psoriasis flare-ups can happen out of the blue and then subside.

Another possible cause of red rash under your breasts is psoriasis. Like eczema, psoriasis is a chronic inflammatory skin disease.

For some people, psoriasis is a mild nuisance. For others, it can be disabling, affecting extensive areas of skin for long periods and often occurring with a distinct type of arthritis (psoriatic arthritis).

A typical treatment option for psoriasis is corticosteroid creams that reduce the appearance and symptoms of a flare-up. Other treatment options include light therapy, sea or sunbathing, and oatmeal baths.

Other causes

Here are some other possible causes of itching under your breasts or an under-breast rash in addition to the conditions mentioned above:

  • A “Christmas tree rash” (pityriasis rosea) looks like fine, itchy, scaly patches of rash that gradually spread over your torso. It’s thought to be triggered by a viral infection. 
  • Ringworm, which is a fungal infection, can appear as itchy, red, scaly, slightly raised bumps surrounded by red rings that grow outward. Ringworm can spread on contact with an infected human or animal and requires proper treatment with antifungal medication.
  • Other types of fungal infection under the breast include candidiasis, which is like having a yeast infection under your breasts. 
  • An early symptom of inflammatory breast cancer is an itchy rash on the breast that looks and feels like an insect bite. If you see breast dimples or nipple changes, be sure to have it looked at by your doctor.
  • Shingles under your breast, or herpes zoster, can cause a painful breast rash, requiring treatment with antiviral medication.
  • Rash may appear as a symptom of several infections (typhoid fever or meningitis, for example), autoimmune diseases (such as lupus or dermatomyositis), or clotting system disorders, but it usually occurs in conjunction with other pronounced symptoms.

When to see a doctor about a rash under the breasts 

Skin rashes come in all sorts of shapes and sizes with varying symptoms. They can be challenging to diagnose, especially if they appear suddenly or without any obvious cause. While some rashes are harmless, others can be potentially life-threatening. 

See your doctor if you have a skin rash with any of the following symptoms: 

  • The rash is fast-spreading over a large area of your body.
  • Your skin is bright red, hot, and thick.
  • You have a fever, shivering, nausea, vomiting, excessive sweating, or abnormal fatigue.
  • Your skin is discolored, blistering, bleeding, or peeling.
  • There are dark, asymmetrical spots with multiple colors.
  • The rash or spots change shape and size.

The takeaway

When it comes to the health of your skin and your breasts, it’s always better to be safe than sorry. While a one-off rash under your breast may not be something to worry about, seek medical attention if the rash spreads, reoccurs, or has other symptoms mentioned above.