Why Do I Have Crust on My Nipples?

Nipple crusting is almost always dried fluid or flaking skin, and in most cases it points to something benign like mild eczema, friction irritation, or normal physiological secretion that has dried on the surface. That said, persistent or one-sided crusting can occasionally signal a condition that needs medical attention, so the cause matters more than the crust itself. Understanding the most common explanations and the handful of red flags worth knowing can save you both unnecessary worry and an overlooked diagnosis.

Dried Secretions From Otherwise Healthy Nipples

Nipples contain openings to several milk ducts, and these ducts can produce tiny amounts of fluid even when you are not pregnant or breastfeeding. The fluid is often clear or slightly yellowish and so small in volume that you never notice it as a liquid. Instead, it dries against your skin or inside your bra and leaves a thin, flaky, or slightly sticky residue. This kind of crusting tends to appear on both sides and does not come with redness, pain, or changes to the nipple’s shape. It is one of the most common explanations people overlook simply because they did not realize non-lactating nipples could produce any discharge at all.

Hormonal shifts can temporarily increase these small secretions. The days around your period, starting or switching a hormonal contraceptive, and perimenopause are all common triggers. If the crusting comes and goes in a pattern that loosely tracks your cycle, that hormonal connection is the likeliest explanation.

Nipple Eczema

Eczema of the nipple is a surprisingly common and frequently misdiagnosed condition. It causes itching, redness, scaling, small cracks in the skin, weeping of clear fluid, and crusting as that fluid dries. The crusting from nipple eczema tends to be yellowish or whitish and can look alarming, but the condition is a benign inflammatory reaction, not an infection or a sign of cancer. It is often triggered by contact irritants like laundry detergent, fabric softeners, synthetic bra materials, or fragranced body products. People with a history of eczema or atopic dermatitis elsewhere on their body are more prone to it.

One reason nipple eczema deserves its own mention is that it is frequently confused with Paget’s disease of the breast, a rare cancer discussed further below. A case report in BMJ Case Reports highlighted that nipple eczema “is frequently misdiagnosed as Paget’s disease of the breast or an infectious process, leading to unnecessary investigations and delayed appropriate treatment.”¹ The practical difference is that eczema usually improves with a mild topical steroid and removal of the irritant, while Paget’s disease does not respond to those treatments and tends to worsen steadily. If you treat what looks like eczema and it is not improving after a few weeks, that non-response itself is a reason to see a doctor.

Friction and Mechanical Irritation

Repeated rubbing of clothing against the nipple can cause irritant dermatitis, and when the abraded skin weeps and dries it leaves a crusty layer. This is the mechanism behind what dermatologists call “jogger’s nipple,” an irritant dermatitis of the nipples caused by friction from a running shirt.² Runners, cyclists, and anyone who exercises in coarse or loose-fitting tops are the classic candidates, but friction-related crusting can happen to anyone wearing a poorly fitting bra, going braless under a rough fabric, or engaging in repetitive upper-body movement at work.

The fix is straightforward: barrier products like petroleum jelly or anti-chafe balm before activity, tighter-fitting moisture-wicking fabrics, and nipple covers or band-aids during long runs. If the crusting clears up once you remove the friction source, you have your answer.

Breastfeeding-Related Crusting

If you are currently breastfeeding or have recently stopped, crusting on the nipples is extremely common and almost always related to dried milk, dried colostrum, or healing micro-injuries from the baby’s latch. Colostrum, the thick yellowish milk produced in late pregnancy and the first days postpartum, is especially prone to drying into visible crusts because of its higher protein content.

Cracked or sore nipples during breastfeeding can also become infected with Staphylococcus aureus, the bacterium behind many skin infections. Research on S. aureus-infected sore nipples found that these infections should be treated aggressively with systemic antibiotics to improve healing and reduce the risk of the infection ascending into the breast tissue and causing mastitis.³ If your crusting is accompanied by increasing pain, spreading redness, warmth, pus-like discharge, or a fever, those are signs of bacterial infection rather than simple dried milk, and you should contact your healthcare provider promptly.

Fungal infections, particularly candida (thrush), can also cause nipple changes during breastfeeding. The hallmarks of nipple thrush tend to be deep, burning or stinging pain that continues between feeds, shiny or flaky skin on the nipple or areola, and sometimes a white film. Your baby may have white patches in their mouth at the same time. This is treated with antifungal medication for both you and the baby simultaneously.

Nipple Piercings

If you have a nipple piercing, some crusting is actually part of the normal healing response. A thin, scant whitish-yellow secretion that crusts on the jewelry and is associated with localized firmness around the piercing site is a normal reaction that may persist throughout the healing period.⁴ Nipple piercings take considerably longer to heal than earlobe piercings, sometimes six months to a year or more, so this normal crusty discharge can last a while.

The line between normal healing crust and an infected piercing matters. Normal crust is pale, scant, and not painful. Infection tends to bring increasing redness, swelling, throbbing pain, green or foul-smelling discharge, and sometimes fever. If any of those appear, see a doctor rather than just removing the jewelry yourself, as removing it can trap the infection inside.

Intraductal Papilloma

An intraductal papilloma is a small, wart-like growth inside one of the milk ducts. It is benign, but it tends to produce discharge, often clear, sticky, or blood-tinged, that can dry into a crust on the nipple. The key distinguishing feature is that the discharge typically comes from a single duct opening and affects only one breast. A case described in BMJ Case Reports documented a woman who presented with a breast lump and bloody nipple discharge that turned out to be a benign papilloma, which was later surgically removed.⁵

Papillomas are most common in people aged roughly 35 to 55 and are one of the leading benign causes of single-duct nipple discharge. They are not cancerous, but because the discharge they produce can look similar to that caused by breast cancer, doctors generally recommend imaging and sometimes excision to confirm the diagnosis.

Erosive Adenomatosis of the Nipple

This is a rare benign growth that arises in the nipple itself rather than inside a duct. It causes erosion of the nipple surface, serous or bloody discharge, swelling, itching, redness, and crusting.⁶ The problem is that it looks almost identical to Paget’s disease both to the naked eye and sometimes even under a microscope, which makes it a diagnostic challenge. Despite that resemblance, it is entirely benign and treated with simple surgical excision. If your doctor mentions this as a possibility, a biopsy is the only way to distinguish it from something more serious.

Paget’s Disease of the Breast

This is the diagnosis everyone understandably worries about when they Google nipple crusting. Paget’s disease of the breast is a form of cancer that starts in the skin of the nipple. It typically shows up as persistent redness, scaling, crusting, or erosion of the nipple that does not go away with typical eczema treatments. One review described it as skin inflammation of the nipple area that is clinically an adenocarcinoma of the nipple’s surface layer.⁷

A few features set Paget’s disease apart from more ordinary causes of crusting. It almost always affects only one nipple. The changes do not come and go; they slowly worsen over weeks to months. Topical steroids and moisturizers provide no lasting relief. The nipple may become flattened, retracted, or develop an ulcerated area. In a study spanning 13 years, 48 women presenting with Paget’s disease of the nipple were identified, all showing nipple eczema-like changes that contained cancer cells on biopsy.⁸

Paget’s disease is rare compared to eczema or friction-related crusting, but its mimicry of benign conditions means it can be misdiagnosed for months. The practical takeaway: unilateral nipple changes that do not improve with standard skin care deserve a biopsy, not just another round of steroid cream.

When Crusting Happens in Men

Men can develop nipple crusting for many of the same benign reasons as women: friction, eczema, psoriasis, or an irritant reaction. However, nipple discharge and crusting in men carry a somewhat different risk profile when it comes to malignancy. In a review from Memorial Sloan Kettering, among patients presenting with nipple discharge over a ten-year period, only about 3% were male, but 57% of those men had an underlying malignancy, compared with 16% of women presenting with the same complaint.⁹ Those numbers come from a cancer center’s patient population, so they are skewed toward higher-risk cases. Still, the broader point holds: nipple discharge in men is uncommon enough that when it does appear, doctors take it seriously and recommend thorough evaluation.

If you are male and noticing persistent crusting that is not obviously from friction or a skin condition you have elsewhere on your body, getting it checked sooner rather than later is reasonable.

Red Flags That Warrant a Doctor Visit

Most nipple crusting is harmless, and if it resolves on its own, comes and goes mildly, or clearly tracks with an identifiable irritant, you probably do not need to rush to a clinic. But certain features shift the picture. Research has emphasized that unilateral nipple discharge, regardless of its color or nature, needs to be evaluated with clinical assessment, cytological evaluation, and imaging.¹⁰

Signs that should prompt a visit to your doctor include:

• One-sided only: crusting, discharge, or skin changes limited to a single nipple, especially if they persist for more than a few weeks.
• Bloody discharge: any red or dark brown fluid, whether or not it dries into a crust.
• Non-healing changes: redness, scaling, or erosion that does not improve with moisturizer or a short course of over-the-counter hydrocortisone.
• Nipple shape changes: new flattening, inversion, or distortion of the nipple.
• A lump beneath: any new palpable mass behind or near the nipple.
• Spontaneous discharge: fluid that appears without squeezing the breast, especially from a single duct opening.

None of these features automatically means cancer. Many will turn out to be papillomas, cysts, or infections. But they do warrant imaging and sometimes a biopsy to rule out the possibilities that matter.

Simple Care for Everyday Nipple Crusting

If your crusting fits the benign pattern, there are a few practical things you can do. Gentle cleaning in the shower with warm water is usually enough to soften and remove dried secretions. Avoid scrubbing or picking at crusts, which can break the skin and invite infection. Unscented, hypoallergenic moisturizers or a thin layer of petroleum jelly can help if dryness and flaking are the main issue. The principle of keeping healing skin properly moisturized rather than letting it dry out and crack has been well established in wound care research for decades.¹¹

Switching to fragrance-free laundry detergent and skipping fabric softener is worth trying if you suspect contact irritation. Bras and sports tops made from smooth, moisture-wicking fabric reduce friction. And if you notice the crusting started around the same time you began using a new body wash, lotion, or topical product on your chest, eliminating that product for a few weeks is a reasonable diagnostic experiment.

Post-Radiation Nipple Changes

If you have a history of breast cancer treatment involving radiation therapy, nipple crusting or non-healing skin changes on the treated breast carry a specific additional consideration. Radiation can cause chronic skin changes in the treated area, including dryness, thinning, and altered texture that persists for years. In rare cases, a non-healing nipple ulcer after radiation can represent a new skin cancer in the irradiated tissue. A case report documented a woman who developed squamous cell carcinoma of the nipple nine years after whole-breast radiation for ductal carcinoma in situ, likely related to chronic radiation damage to the skin.¹²

This scenario is rare, but if you have had breast radiation and develop a new or changing nipple lesion, especially one that does not heal over several weeks, it deserves prompt evaluation by your oncology team rather than watchful waiting.

Nipple Crusting in Infants

Parents sometimes notice discharge or crusting on a newborn’s nipples and understandably panic. Milky nipple discharge in infants is actually fairly common and results from residual maternal hormones circulating in the baby’s system after birth. It typically resolves on its own within a few weeks. Even bloody nipple discharge, while very rare and alarming in appearance, can be benign. One documented case involved a four-month-old breastfed infant with bilateral bloody nipple discharge whose workup revealed only mammary duct ectasia, a benign widening of the ducts. The symptoms resolved spontaneously within six weeks without any specific treatment.¹³

That said, any nipple discharge in an infant that is bloody, persistent, or accompanied by redness and swelling should be evaluated by a pediatrician to rule out infection or other causes, even though the outcome is usually reassuring.