Breast and Nipple Thrush and other bacterial infections
Candida is a yeast that can be present naturally on the skin and in the mouth, gut and other parts of the body without causing infection. An overgrowth can cause candidiasis, more commonly known as thrush.
Candida can cause oral thrush in babies. However, the diagnosis of Candida infection affecting the nipple or breast during breastfeeding is less straightforward. Nipple pain, burning sensations and pain radiating into the breast have often been attributed to Candida, sometimes leading to antifungal treatment for both the breastfeeding parent and baby. Current evidence questions whether Candida is responsible for many of these symptoms.
A review by Douglas (2021) found that the evidence linking Candida detected in breast milk or on the nipple to breastfeeding pain is inconsistent. Candida may be detected in people who have no symptoms, and the presence of the organism does not, by itself, establish that it is causing an infection. The review also highlighted the risk of overlooking other explanations for pain and using antifungal treatment when it may not be appropriate.
The UNICEF UK Baby Friendly Initiative's updated information sheet on Candida (2025) similarly highlights the need to reconsider the routine diagnosis of nipple thrush and the assumption that Candida is commonly passed between breastfeeding parents and babies. It recommends skilled assessment of breastfeeding and consideration of other causes of pain before antifungal treatment is started.
This does not mean that Candida infection cannot occur. It means that symptoms such as burning nipple pain, shiny skin or breast pain between feeds should not automatically be diagnosed as thrush.
Candida testing and diagnosis
Testing may be considered where Candida infection is suspected, but a positive result does not necessarily establish an active infection or explain the symptoms being experienced.
Candida can be present without causing disease. Its detection needs to be interpreted alongside the clinical presentation and assessment findings. A positive test should not be used in isolation to justify antifungal treatment, particularly where other possible causes of nipple or breast pain have not been explored.
Testing may involve a sample from the nipple or affected skin, or a breast milk sample. A swab or other sample may detect Candida, but this does not prove that it is responsible for pain or that the breastfeeding parent has an active infection. The same consideration applies to breast milk testing: detection of Candida in a milk sample does not establish that it is causing symptoms or that the baby has an infection.
Testing may be appropriate in selected circumstances, particularly where the diagnosis is uncertain, symptoms persist or treatment has not been effective. It is not a routine requirement for every breastfeeding parent experiencing nipple pain.
Other causes of nipple and breast pain
Persistent nipple or breast pain deserves a thorough assessment. Treating presumed thrush without identifying the cause may delay appropriate support and expose the breastfeeding parent or baby to medication that may not be needed.
The Breastfeeding Network reviewed its approach to persistent breast and nipple pain in November 2024. It withdrew its previous thrush factsheets while reassessing the evidence and now encourages families and healthcare professionals to consider other possible causes of pain and prioritise skilled breastfeeding support.
The following are some of the causes that may need to be considered.
Positioning and attachment
Ineffective positioning and attachment are common contributors to nipple pain. If a baby attaches shallowly or compresses the nipple during feeding, repeated friction and pressure can cause soreness, damage, cracking or bleeding.
The appearance of the nipple after a feed can provide useful information. A nipple that appears flattened, ridged or lipstick-shaped may indicate compression. Persistent pain, rather than brief initial sensitivity that settles quickly, warrants further assessment.
An observed feed can help identify whether the baby's position, attachment, oral function or milk transfer may be contributing. Changes to positioning and attachment may improve comfort, but persistent pain or nipple damage needs further investigation.
Further reading:
Hand expressing and breast pump expressing
Expressing milk should not cause ongoing pain or damage. Hand expression can become uncomfortable if the nipple is pinched, pulled or compressed rather than pressure being applied behind the nipple to move milk forwards.
With a breast pump, discomfort may be associated with an unsuitable flange size or shape, excessive suction, friction or the position of the nipple within the flange. A flange that is too small or too large can contribute to rubbing, swelling and nipple trauma.
Pain should not be treated as an inevitable part of expressing. The equipment, flange fit, suction setting and expressing technique may all need to be reviewed.
Further reading:
Dermatitis, eczema and psoriasis
Skin conditions can affect the nipple and areola and may cause itching, redness, soreness, scaling, cracking or weeping. Eczema, irritant or allergic contact dermatitis and psoriasis are among the possible causes.
Repeated exposure to moisture, friction, breast pads, laundry products, soaps, creams or other topical products may aggravate sensitive skin. The appearance can vary, and changes may be harder to recognise on darker skin tones.
Where a skin condition is suspected, assessment should consider the wider pattern of symptoms, any history of skin problems and possible irritants or allergens. Persistent, unusual or one-sided nipple changes should be assessed by a healthcare professional rather than assumed to be a breastfeeding-related infection.
Nipple vasospasm and Raynaud's phenomenon
Vasospasm occurs when the blood vessels supplying the nipple temporarily narrow, reducing blood flow. It may cause sharp, burning or throbbing pain during or after a feed, and can also occur between feeds.
A nipple may change colour as blood flow alters. It may become white, then blue or purple, before returning to its usual colour. These changes are not always visible, particularly on darker skin tones.
Vasospasm can be triggered by cold and may occur after nipple compression or trauma during feeding. Improving positioning and attachment may help where compression is contributing, but persistent symptoms may need further assessment.
Further reading:
Neuropathic pain (nerve pain)
Neuropathic pain is pain caused by irritation or dysfunction of the nerves involved in sensation. It may be described as burning, shooting, electric-shock-like, tingling or stabbing pain. It can occur during feeding, afterwards or between feeds.
The description of pain alone does not establish a neuropathic diagnosis. Other causes, including nipple trauma, vasospasm, skin conditions and breast inflammation, need to be considered. Persistent pain may require assessment by a healthcare professional with appropriate expertise.
SSRIs
Selective serotonin reuptake inhibitors (SSRIs) are medicines commonly prescribed for depression and anxiety. Their potential relationship with persistent nipple or breast pain has been discussed in clinical case discussions, including work presented by Naomi Dow.
This is an area where the evidence is limited. A possible association should not be interpreted as proof that an SSRI is causing pain, and prescribed medication should not be stopped or changed without advice from the prescribing clinician. Where pain begins or changes after starting a medicine or altering a dose, this information can be included in the clinical assessment.
Bacterial infection, breast inflammation and the breast microbiome
Not all breast inflammation is caused by bacteria, and not every cracked or sore nipple is infected. It is important to distinguish local skin infection from inflammation within the breast, and to recognise when further medical assessment is needed.
Infected nipple wounds
Cracks, fissures and other breaks in the nipple skin can provide an entry point for bacteria. Staphylococcus aureus is one organism that has been identified in infected sore nipple wounds.
However, a damaged nipple is not automatically infected. Pain and cracking can arise from mechanical trauma, including repeated compression or friction during feeding or expressing. A wound that is increasingly painful, inflamed, weeping, crusted or producing pus needs clinical assessment.
Where bacterial infection is suspected, a healthcare professional may consider a swab and appropriate treatment. The choice of treatment depends on the appearance and extent of the infection, the clinical assessment and any relevant test results. Persistent or worsening symptoms should not be managed solely by changing feeding technique or applying topical products without assessment (Livingstone and Stringer, 1999).
Impetigo
Impetigo is a contagious bacterial skin infection. It commonly affects the face and hands but can occur on other areas of skin, including around the nipple.
It may begin as red sores or blisters that break down and develop golden or honey-coloured crusts. Impetigo can spread through direct contact with infected skin or contaminated items, so advice about hygiene and treatment is important.
A suspected infection around the nipple should be assessed so that appropriate treatment can be selected. The NHS advises that impetigo usually affects skin that is already damaged, such as through a cut, scratch or an existing skin condition (NHS, 2024).
Mastitis: inflammation and bacterial infection
Mastitis describes inflammation of the breast. It is most common during breastfeeding, but it can also occur in people who are not breastfeeding.
Breast inflammation may involve swelling, tenderness, warmth and pain, sometimes accompanied by a firm or swollen area. Some people also experience flu-like symptoms, including aches, chills or a raised temperature.
Mastitis is not always caused by a bacterial infection. Inflammation can develop when milk is not being removed effectively or when there is localised swelling and narrowing within the breast. Bacterial mastitis is a possible progression, but the two terms should not be used interchangeably.
The Academy of Breastfeeding Medicine's Clinical Protocol #36 describes mastitis as a spectrum that includes ductal narrowing, inflammatory mastitis, bacterial mastitis, phlegmon and abscess (Mitchell et al., 2022). This helps explain why not every episode of breast inflammation requires antibiotics.
Assessment is important where symptoms are severe, worsening or not improving. Antibiotics may be required when bacterial mastitis is diagnosed or suspected. Families should seek medical advice if symptoms are not improving within 12 to 24 hours of appropriate self-care, or sooner if they feel very unwell. The NHS advises continuing to breastfeed if possible and avoiding excessive pumping or firm breast massage (NHS, Mastitis).
Further reading:
Breast abscess
A breast abscess is a collection of pus within the breast tissue. It can develop as a complication of mastitis and may present as a painful, swollen or warm area, sometimes with a persistent lump. A person may also feel generally unwell.
An abscess needs medical assessment. Ultrasound may be used to identify the collection, and treatment commonly involves draining the pus. Antibiotics may also be needed.
Breastfeeding or expressing can often continue during treatment, but the plan depends on the location of the abscess, the procedure used and the individual's circumstances. A healthcare professional should advise on feeding from the affected breast and any wound-care precautions.
A persistent or worsening lump should not be assumed to be a blocked duct or uncomplicated mastitis. It needs assessment to establish the cause.
The breast microbiome and dysbiosis
The breast has a microbiome: a community of microorganisms that may include bacteria and other organisms. Research into the breast microbiome and how it may relate to breastfeeding, inflammation and pain is continuing.
The term dysbiosis is used to describe a change or imbalance in a microbial community. It is not, by itself, a diagnosis of bacterial infection. Detecting particular organisms, or identifying differences between microbial communities, does not automatically establish that they are causing symptoms or that antimicrobial treatment is needed.
Research into the breast microbiome is still developing. The presence of bacteria in breast milk should not be interpreted as evidence that milk is contaminated or that the breastfeeding parent has an infection. Clinical findings and the person's symptoms remain important when deciding whether investigation or treatment is appropriate (Douglas, 2021).
Oral thrush in babies
Oral thrush is a recognised Candida infection in babies. It commonly presents as creamy white patches, known as plaques, inside the mouth. These may appear on the tongue, gums, inside the cheeks or the roof of the mouth. The affected areas can become sore and feeding may be uncomfortable (Kingston and Richmond NHS Foundation Trust, 2024; UNICEF UK Baby Friendly Initiative, 2025).
Milk residue and a coated tongue
A white coating on a baby's tongue is not necessarily oral thrush. Milk residue can collect on the surface of the tongue, around the filiform papillae (the small projections that give the tongue its textured appearance).
The tongue's movement against the palate during feeding helps to clear material from its surface. Where tongue elevation is restricted, this natural cleaning action may be less effective and a coating may be more noticeable. This may be one explanation for a persistent white coating on the tongue, although it is not, by itself, evidence of tongue-tie or a Candida infection.
Milk residue is more likely to be confined to the tongue, whereas oral thrush can also affect the gums, inside of the cheeks and roof of the mouth. Thrush plaques are not usually removed by gently wiping with a clean cloth. They should not be scraped or forcibly removed. Where there is uncertainty, or the baby has feeding difficulties, discomfort or other symptoms, clinical assessment is appropriate (Kingston and Richmond NHS Foundation Trust, 2024; UNICEF UK Baby Friendly Initiative, 2025).
Signs and symptoms
Oral thrush may cause no obvious discomfort, particularly when the infection is mild. Some babies may show:
Creamy white plaques on the tongue, gums, inside of the cheeks or roof of the mouth.
Soreness or discomfort around the mouth.
Unsettled behaviour during feeds.
Reluctance to feed or difficulty maintaining their usual feeding pattern.
A white film on the lips.
Some babies with oral thrush also have a persistent nappy rash associated with Candida. However, the presence of one symptom does not, by itself, establish the other. Each area needs to be assessed in its own right (Kingston and Richmond NHS Foundation Trust, 2024; NHS, Thrush – breastfeeding).
If a baby is feeding less than usual, it is important to consider their overall milk intake, hydration and weight gain, rather than concentrating only on the appearance of the tongue. A baby who is reluctant to feed, has fewer wet nappies or appears unwell needs prompt assessment.
Diagnosis and management
Oral thrush is usually diagnosed from the appearance of the mouth and the baby's symptoms. A swab is not routinely required for an uncomplicated presentation, although a healthcare professional may consider one if the diagnosis is uncertain or symptoms are persistent or recurrent.
Mild cases may resolve without treatment. Where treatment is needed, an antifungal medicine may be prescribed or supplied following an appropriate assessment.
Miconazole oral gel is used to treat oral candidiasis. The product information specifies that it is suitable for infants aged four months and older, provided their swallowing reflex is sufficiently developed. The dose for infants is divided into smaller portions and applied to the affected areas with a clean finger. It must not be placed at the back of the throat because of the risk of choking.
The manufacturer's product information also highlights that swallowing development varies between infants. The lower age limit should be increased to five or six months for infants who were born prematurely or who have slow neuromuscular development. The baby's gestation, development and individual circumstances therefore need to be considered before the medicine is supplied or used (McNeil Products Ltd, 2026).
It is important to distinguish between the two UK miconazole oral gel products. Daktarin Sugar Free 2% Oral Gel is available as a Pharmacy medicine, whereas standard Daktarin Oral Gel is a Prescription Only Medicine. The product classification does not remove the need for an appropriate assessment. A pharmacist must consider whether supply is suitable, including the baby's age, swallowing development and any relevant precautions. Nystatin oral suspension is another antifungal treatment that may be prescribed where clinically appropriate.
Families should follow the instructions supplied with the specific product and the advice of the prescribing or supplying healthcare professional. Medicines should not be applied to the nipple for the baby to suck from unless specifically advised by an appropriate prescriber.
Breastfeeding can generally continue while a baby is being treated for oral thrush. If feeding is too uncomfortable for the breastfeeding parent or baby, expressing may help maintain milk removal while further support is arranged.
Expressed breast milk during treatment
Families have previously been advised to label milk expressed during a thrush infection and avoid freezing it for later use, because freezing does not reliably kill yeast and there was concern that the milk could cause reinfection.
Current NHS breastfeeding guidance states that there is no evidence to suggest that using expressed or stored milk during a thrush infection causes reinfection. It advises that expressed milk can be used while the breastfeeding parent and baby are receiving treatment (NHS, Thrush – breastfeeding).
The NHS also has general oral-thrush information that continues to advise against freezing milk for later use, so published guidance is not entirely consistent. Families should not be told to discard expressed milk solely because it was collected during treatment. Milk should still be labelled and dated as part of ordinary breast milk storage practice, and stored in accordance with current guidance (NHS, Storing breast milk).
When to seek further support
Persistent nipple or breast pain deserves assessment, particularly where it is affecting feeding, expressing, sleep or wellbeing. Increasing redness or swelling, pus, spreading skin changes, fever, flu-like symptoms or a baby who is feeding poorly or becoming unwell should prompt medical advice.
A skilled infant feeding assessment can help explore positioning and attachment, milk transfer, expressing technique and possible oral function difficulties. An infant feeding specialist or International Board Certified Lactation Consultant (IBCLC) can support families with breastfeeding challenges and help identify when referral to another healthcare professional is needed.
An IBCLC or infant feeding specialist does not replace medical assessment where infection, a skin condition or another medical cause is suspected. Equally, persistent pain should not automatically be attributed to Candida or treated with antifungal medication without considering other explanations.
Further information:
The most useful starting point is a careful assessment of the feeding dyad and the symptoms being experienced. Identifying the cause of pain matters: it helps families access appropriate support and reduces the risk of unnecessary treatment.
References
Douglas, P. (2021) ‘Overdiagnosis and overtreatment of nipple and breast candidiasis: A review of the relationship between diagnoses of mammary candidiasis and Candida albicans in breastfeeding women’, Women's Health, 17, pp. 1–15. doi: 10.1177/17455065211031480.
Kingston and Richmond NHS Foundation Trust (2024) Oral thrush in babies. Last updated 9 December 2024.
Livingstone, V. and Stringer, L.J. (1999) ‘The treatment of Staphylococcus aureus infected sore nipples: a randomized comparative study’, Journal of Human Lactation, 15(3), pp. 241–246. doi: 10.1177/089033449901500315.
McNeil Products Ltd (2026) Daktarin Oral Gel: Summary of Product Characteristics. Last updated 4 September 2026. Available at: https://www.medicines.org.uk/emc/product/14746/smpc
Mitchell, K.B. et al. (2022) ‘Academy of Breastfeeding Medicine Clinical Protocol #36: The Mastitis Spectrum, Revised 2022’, Breastfeeding Medicine, 17(5), pp. 360–376. doi: 10.1089/bfm.2022.29207.kbm.
NHS (2024) Impetigo. Page last reviewed 6 June 2024. Available at: https://www.nhs.uk/conditions/impetigo/
NHS (date not displayed) Mastitis. NHS website. Available at: https://www.nhs.uk/conditions/mastitis/
NHS (date not displayed) Storing breast milk. NHS website. Available at: https://www.nhs.uk/baby/breastfeeding-and-bottle-feeding/breastfeeding/expressing-breast-milk/
NHS (date not displayed) Thrush – breastfeeding. NHS Best Start in Life. Available at: https://www.nhs.uk/best-start-in-life/baby/feeding-your-baby/breastfeeding/breastfeeding-challenges/thrush/
UNICEF UK Baby Friendly Initiative (2025) Information sheet on Candida (thrush). April 2025. Available at: https://www.unicef.org.uk/babyfriendly/wp-content/uploads/sites/2/2025/04/Infosheet-on-thrush.pdf
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