Mastitis

Related Terms

Abscess, breast, breast abscess, breast tissue, breastfeeding, chemotherapy, infection, inflammatory breast cancer, mastectomy, modified radical mastectomy, radiation therapy.

Background

Mastitis is the medical term for inflammation of the breast tissue. It is typically caused by an infection in the milk ducts or breast tissue, and symptoms generally include pain, swelling, and redness of the breast. Most people develop mastitis in just one breast, but it is possible to develop swelling in both. Mastitis rarely occurs in men.
Breast tissue infections usually occur in breastfeeding women, within three months after they give birth. However, the condition may develop at any point during breastfeeding.
Infections of the breast tissue are effectively treated with antibiotics that are usually taken for 10-14 days. Mothers with mastitis can safely continue breastfeeding because the infection cannot be passed through the breast milk. In fact, keeping the milk flowing in the infected breast helps get rid of the infection. If the nipples are too painful to continue breastfeeding, a breast pump may be used to empty the breast. However, some antibiotics may be harmful for nursing infants. Patients should ask their doctors if they can continue breastfeeding while taking medications.
In rare cases, mastitis may be a symptom of a rare form of breast cancer called inflammatory breast cancer. Patients with this type of cancer typically receive chemotherapy, radiation therapy, and/or surgery. About 50% of patients diagnosed with inflammatory breast cancer survive five years after diagnosis, and about 33% survive 10 years or more after diagnosis.

Signs and symptoms

Infection: The breast is typically swollen and may feel warm and tender to the touch. Other symptoms may include pain or a burning sensation during breastfeeding, a general feeling of discomfort, reddening of the skin on the breast, and fever.
Inflammatory breast cancer: Patients with inflammatory breast cancer experience swelling in their breasts. Additional symptoms may include itching on the breast, pink or red-colored skin on the breast, ridges and thickened areas of skin on the breast, a bruise-like appearance on the breast, nipple retraction, nipple discharge (which may or may not be bloody), breast pain, change in color and texture of the areola, or the breast may be warm to the touch.

Diagnosis

Infection: Testing is usually not generally needed to diagnose mastitis. Instead, a doctor typically diagnoses mastitis based on a physical examination. The doctor looks for characteristic signs of the condition, including a fever, chills, and a painful area in the breast.
During the examination, a doctor will also check to see if the patient has developed a collection of pus, called an abscess, in the breast tissue. This is a common complication that develops when mastitis is left untreated.
Inflammatory breast cancer: If inflammatory breast cancer is suspected, a biopsy is performed to determine if the patient has cancer. A small sample of the patient's breast tissue is analyzed in a laboratory for cancerous cells.

Complications

Abscess: If mastitis is not properly treated or it is related to a plugged milk duct (called milk stasis), a collection of pus (called an abscess) may develop in the breast tissue. An abscess usually feels like a small, hard lump in the breast. Patients with breast abscesses usually need to have the fluid surgically drained. Some research suggest that as many as 10% of women with mastitis develop abscesses. However, many experts consider this estimate to be very high.
Recurrence: Women who have had mastitis in the past are more likely to experience the condition again in the future.

Treatment

General: Mastitis that is caused by an infection is treated with antibiotics and self-care techniques, such as warm compresses and gentle massaging, to increase milk flow and reduce pain. Mothers with mastitis can safely continue breastfeeding because the infection cannot be passed through the breast milk. In fact, keeping the milk flowing in the infected breast helps get rid of the infection. If the nipples are too painful to continue breastfeeding, a breast pump may be used to empty the breast. However, some antibiotics may be harmful for nursing infants. Patients should ask their doctors if they can continue breastfeeding while taking medications.
Mastitis that is caused by inflammatory breast cancer is treated with chemotherapy, radiation therapy, and/or surgery. Even with treatment, recurrence is generally high with this type of cancer, particularly within 10 years of diagnosis. It is unsafe for women to breastfeed while they are undergoing chemotherapy.
Infection:
Antibiotics: If an infection is causing mastitis, patients usually take antibiotics by mouth for 10-14 days. Cephalexin (Keflex?) and dicloxacillin (Dycill?) are commonly prescribed, but they are not safe for nursing infants. Erythromycin may be prescribed if a patient is allergic to other antibiotics. Erythromycin is generally considered safe during breastfeeding. Side effects depend on the specific medication used. In general, common side effects include mild nausea, vomiting, heartburn, muscle aches, diarrhea, dizziness, fatigue, joint pain, vaginal itching, or vaginal discharge.
It is important that patients take their medications exactly as prescribed. Patients should not stop taking medication early, even if symptoms start to go away, because bacteria may still be present in the body. Not only may the infection return if medication is stopped too early, but it may also lead to antibiotic resistance. If the antibiotic therapy is not completed, the few remaining bacteria in the body that survive may become resistant to treatment, and once this happens, the antibiotic will no longer be effective if taken in the future.
Mild pain relievers: Until the antibiotics start to be effective, people may take mild pain relievers, such as ibuprofen (Advil? or Motrin?) or acetaminophen (Tylenol?).
Increase milk flow: Before breastfeeding, mothers can put a warm compress over the affected breast for about 15 minutes to reduce pain and increase milk flow. Alternatively, patients can take a warm shower and/or gently massage the affected breast.
Inflammatory breast cancer:
Chemotherapy: Patients with inflammatory breast cancer typically undergo several sessions of chemotherapy before surgery. The chemotherapy drugs help kill the cancer cells in the body. This helps shrink the size of the cancer so that surgery may be more effective. After surgery is performed, chemotherapy treatments and/or radiation therapy are given again in order to kill any cancer cells that may still be in the body.
Breastfeeding is not safe for patients who are undergoing chemotherapy. Common side effects include nausea, vomiting, fatigue, hair loss, anemia, confusion, depression, problems with blood clotting, sores in the mouth (called stomatitis), sores in the throat (called mucosititis), dry mouth, diarrhea, constipation, loss of appetite, peripheral neuropathy (which causes burning, weakness, tingling, or numbness in the hands and/or feet), acne, dry skin, rash, yellow and brittle nails, flu-like symptoms, fluid retention, decreased sperm motility, and reduced sexual hormone production in women. Some chemotherapy drugs may also damage the kidneys and/or bladder. Chemotherapy also destroys healthy immune cells. Therefore, patients undergoing chemotherapy have weakened immune systems and are susceptible to infections.
Surgery: Surgery is typically performed after chemotherapy in order to increase the chances that surgery will be effective. Due to the nature of the cancer, the entire breast generally needs to be removed. This type of surgery is called a mastectomy. During surgery, the surgeon will also examine the lymph nodes to determine if the cancer has spread to other parts of the body. If the lymph nodes under the arm are removed in addition to the breast, the procedure is called a modified radical mastectomy
Radiation therapy: Patients often receive radiation therapy after surgery. This helps reduce the chance that the cancer will return. In such cases, radiation is usually started three to four weeks after surgery. Patients typically receive treatment five days a week for five to six consecutive weeks. The treatments are painless and are similar to getting an X-ray. Each session takes about 30 minutes.
Radiation therapy may be the primary course of treatment for patients who cannot undergo surgery.
Common side effects include fatigue, nausea, vomiting, weight loss, and loss of appetite. In a small percentage of women, more serious problems may occur, including arm swelling, damage to the lungs, heart, or nerves or a change in the appearance and consistency of breast tissue. Radiation therapy may also slightly increase the risk of developing another tumor.

Integrative therapies

Traditional or theoretical uses lacking sufficient evidence:
Black cohosh: Black cohosh is apopular herbal remedy that is used to treat menopausal symptoms, such as hot flashes, migraine headache, mood changes, sleep changes, sweating, fast heartbeat, and vaginal dryness. It has been suggested, but not scientifically proven, that black cohosh may help treat mastitis.
Use cautiously if allergic to members of the Ranunculaceaefamily, such as buttercups or crowfoot. Use cautiously with hormone-sensitive conditions (e.g. breast cancer, ovarian cancer, uterine cancer, or endometriosis). Use cautiously if allergic to aspirin products, nonsteroidal anti-inflammatory drugs (NSAIDs), or blood-thinners. Use cautiously if taking hormone replacement therapy or blood pressure-lowering medications. Use cautiously with seizures, thromboembolic disease, stroke, or liver disease.
Chamomile: Although some people have used chamomile to treat symptoms of mastitis, the safety and effectiveness of this therapy has not been studied. Until research is performed in this area, a firm conclusion cannot be made.
Avoid if allergic to chamomile or any related plants, such as aster, chrysanthemum, mugwort, ragweed, or ragwort. Avoid with heart disease, breathing disorders, hormone-sensitive conditions, or central nervous system disorders. Avoid if taking cardiac depressive agents, central nervous system depressants, respiratory depressive agents, or anticoagulants. Use cautiously if taking benzodiazepine, anti-arrhythmic medications, calcium channel blockers, alcohol, sedative agents, anxiolytic medications, spasmolytic drugs, oral medications, or agents that are broken down by the liver. Use cautiously if driving or operating machinery. Avoid if pregnant or breastfeeding.
Comfrey: Comfrey (Symphytum spp.) is native to both Europe and Asia and has traditionally been used as both a food and forage crop. It has been proposed that comfrey may help treat mastitis. However, research is currently lacking.
Avoid if allergic to comfrey, its constituents, or members of the Boraginaceae family. Do not take comfrey by mouth or apply it to broken skin because it has been shown to have toxic effects on the liver and may cause cancer. Avoid topical comfrey if at risk for liver disorders, cancer, or immune disorders. Use topical creams containing comfrey cautiously if taking anti-inflammatory medications or cytochrome P450 3A4-inducing agents. Use extreme caution when using topical creams containing comfrey for extended periods. Avoid if pregnant or breastfeeding.
Pokeweed: In folk medicine, pokeweed leaves have been used for rheumatism, arthritis, emesis, and purging. It has been suggested that pokeweed may help treat mastitis because some evidence suggests that pokeweed has anti-inflammatory effects. However, until well-designed human studies are performed, it remains unknown if pokeweed can safely and effectively treat mastitis.
Avoid if allergic to pokeweed, its constituents, or any member of the Phytolaccaceae family. Avoid pokeweed root, leaf, and berry in all patients (adults, children, and pregnant or breastfeeding women) due to reports of toxicity. Use cautiously with liver disorders or HIV. Dosing and efficacy are unclear based on currently available literature. Use cautiously if taking antihypertensive medications or herbs, anti-inflammatory drugs or herbs, antiviral medications, cardiac glycoside drugs and herbs, diuretics, or heparin or other hydrophobic drugs or herbs. Avoid if pregnant or breastfeeding.

Prevention

General: Patients can take steps to reduce their risks of developing mastitis. However, some cases, especially those caused by inflammatory breast cancer, may not be entirely preventable.
Avoid nipple piercings: Nipple piercings increase the risks of developing infections that cause mastitis in both men and women. People who have nipple piercings are encouraged to regularly clean their nipples with soap and warm water.
Empty the breast during breastfeeding: Breastfeeding mothers can reduce their risk of developing mastitis by completely draining the milk from their breasts. Mothers are encouraged to let their babies completely empty one breast before switching to the other. With each feeding, mothers should switch the breast used to breastfeed first. A breast pump may be used to empty the breast. Changing feeding positions may also help ensure that the breast milk is emptied during feeding. Do not wait until the breasts are overfull to begin breastfeeding.
Good hygiene: People are encouraged to practice good hygiene. Regularly washing the hands and nipples with warm soap and water may help reduce the risk of developing infections.
Limit alcohol consumption: Drinking two or more alcoholic beverages a day appear to increase the risk of many types of cancer, including inflammatory breast cancer. Therefore, people are encouraged to consume alcohol in moderation.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Aabo O, Matheson I, Aursnes I, et al. [Mastitis in general practice. Is bacteriologic examination useful?] [Article in Norwegian] Tidsskr Nor Laegeforen. 1990 Jun 20;110(16):2075-7.
Fetherston CM, Lai CT, Hartmann PE. Relationships between symptoms and changes in breast physiology during lactation mastitis. Breastfeed Med. 2006 Autumn;1(3):136-45.
Foxman B, D'Arcy H, Gillespie B, Lactation mastitis: occurrence and medical management among 946 breastfeeding women in the United States. Am J Epidemiol. 2002 Jan 15;155(2):103-14.
Kaufmann R, Foxman B. Mastitis among lactating women: occurrence and risk factors. Soc Sci Med. 1991;33(6):701-5.
Lawrence RA. Mastitis while breastfeeding: old theories and new evidence. Am J Epidemiol. 2002 Jan 15;155(2):115-6.
National Cancer Institute (NCI). .
National Institutes of Health (NIH). .
Natural Standard: The Authority on Integrative Medicine. .
Osterman KL, Rahm VA. Lactation mastitis: bacterial cultivation of breast milk, symptoms, treatment, and outcome. J Hum Lact. 2000 Nov;16(4):297-302.
Susan G. Komen Foundation. .

Causes

Infection: Mastitis usually occurs when bacteria enter the breast through a break in the skin of the nipple or through the opening to the milk ducts in the nipple. Once inside the tissue, the bacteria multiply and cause an infection.
Mastitis often occurs during breastfeeding. This is partly because it is easy for bacteria from the baby's mouth and mother's skin to enter the breast through the nipple. An infection may also occur if a woman's breast becomes too full of milk. This may happen if a mother misses a feeding or has not completely emptied the breast. When the breast is overfull, milk may leak into the breast tissue. As a result, the surrounding breast tissue is vulnerable to infection.
Bacteria may also enter the breast tissue through cracks, open sores, or cuts in the nipples of women who are not breastfeeding or men. In addition, mastitis may occur in people who have pierced nipples. This is because the holes in the skin allow bacteria to enter the nipples and cause infections.
Postmenopausal women may develop chronic mastitis as a result of their bodies' hormonal changes. The hormonal changes may cause the ducts below the nipple to become blocked with debris and dead skin cells. This causes swelling and makes the person vulnerable to bacterial infections.
Inflammatory breast cancer: Although uncommon, mastitis may also be caused by a rare form of cancer called inflammatory breast cancer. Inflammatory breast cancer occurs when cancer cells multiply inside the lymphatic vessels above the breast. These cells eventually clog the vessels, causing the breast to become red, swollen, and dimpled.

Risk factors

Infection:
Breastfeeding: Most cases of mastitis are caused by infections that happen during breastfeeding. This is partly because bacteria from the mother's skin or the baby's mouth can easily enter the breast through the nipple during feeding and cause an infection.
Breastfeeding mothers who wear nipple shields or shells, breast pads, or other breast-feeding aids have an even greater risk of developing mastitis. Although these aids help infants feed efficiently, they may block milk flow and increase germs on the nipple, increasing the chance of infection.
Wearing a tight-fitting bra during lactation also increases the risk because the bra may restrict milk flow.
Breastfeeding women who have sore or cracked nipples have an increased risk of developing mastitis.
History of mastitis: People who have had mastitis in the past are more likely to experience the condition again in the future.
Hormonal changes: Post-menopausal women have an increased risk of developing mastitis. This is because hormonal changes may cause the ducts below the nipple to become blocked with debris and dead skin cells. This causes swelling and makes the breast tissue vulnerable to bacterial infections.
Nipple piercings: Nipple piercings (in women or men) also increase the risk of developing mastitis.
Nipple sores: Men or women who have cracks, open sores, or cuts in their nipples have an increased risk of developing mastitis.
Inflammatory breast cancer:
Age: The risk for inflammatory breast cancer increases with age.
Alcohol consumption: Drinking two or more alcoholic beverages a day appears to increase the risk of many types of cancer, including inflammatory breast cancer.
Hormonal therapy/birth control pills: People who take estrogen and progesterone, including birth control pills, appear to have an increased risk of developing inflammatory breast cancer.
Medical history: People who have had breast cancer or non-cancerous breast disease in the past have an increased risk of developing inflammatory breast cancer. In addition, people who have family histories of breast cancer have an increased risk of developing inflammatory breast cancer. This is because some cases have been linked to inherited genetic mutations.
Race: Caucasians are more likely to develop inflammatory breast cancer than the general population. This is because some cases have been linked to inherited genetic mutations.
Radiation therapy: People who have undergone radiation therapy on the breast or chest area have an increased risk of developing inflammatory breast cancer.