When you schedule a mammogram, you’ll hear what’s become standard advice for the day of your screening: don’t wear underarm deodorant or antiperspirant. The same goes for any powders, creams, or lotions applied under the arms, in the chest area, or on the breast skin. You might be told that deodorant and other skin products can affect the quality of the images. But why is that, exactly?
Deodorant can look like calcifications
Many deodorants contain metallic substances — aluminum is a common culprit — and on a mammogram, their dense particles can look just like calcifications. Calcifications are small deposits of calcium that show up as bright white specks or dots on the soft tissue background of the breasts because the calcium absorbs the X-rays from mammograms.
Calcifications are a sign of some underlying process that is happening in the breast tissue. Usually that process isn’t worrisome. Tissue injury or infection, cysts or other benign (non-cancerous) growths, and even simple aging are common causes of calcifications.
But sometimes calcifications can be a sign of an early cancer developing inside a breast duct. When abnormal cells grow unchecked inside the duct, the cells might get so crowded that some of them die and the body can’t clear them away. If this happens, those cells can harden (or petrify), and areas of calcification form. That’s why physicians take calcifications so seriously.
“Calcifications look like little dots of sand, and the metallic particles in some deodorants can also look like little grains of sand,” says Delia Keating, M.D., a breast imaging radiologist at Memorial Sloan Kettering Cancer Center in New York City. Even though deodorant is applied in “a typical location, high up in the axilla (underarm area),” she adds, a woman also could have calcifications there. “It’s just very hard to distinguish.”
When calcifications appear as a new finding on a woman’s mammogram, the radiologist reading the images tries to figure out if they have any features that could suggest there is an underlying cancer. In many cases, additional imaging is needed. If you wear deodorant to your mammogram, you could end up having additional tests you don’t really need. “We try to avoid repeat imaging as much as possible,” Dr. Keating says.
What about natural deodorants?
What about the growing number of natural deodorants that don’t contain aluminum, but instead use charcoal, baking soda, zinc, plant extracts, or other ingredients? Are those safe for a mammogram? Not necessarily, says Dr. Keating, because in theory, anything that leaves particles in the underarm area could create a problem. So it’s always better to be safe than sorry.
“It’s hard to read labels and know what products contain, and the formulations can change,” Dr. Keating says. “It’s best to avoid the product that day just to be sure it doesn't get confused with some kind of abnormality. Bring the deodorant with you and apply it afterward.”
Skip the creams and powders, too
Dr. Keating stresses that the same advice holds for any lotions, creams, or powders applied on or around the breasts: skip them that day. She notes that some women use a rash ointment under the breasts to help with chafing. These products can deposit small particles in the area, as can the “glowing skin” body lotions that contain metallic particles. Any lotion can be a problem — because it can not only interfere with imaging, but also make the breasts slippery.
“One of the purposes of compression [during mammography] is to get as much of the breast tissue on the plate as possible,” Dr. Keating notes. It’s harder for the technologist to get clear images if the skin is slippery, because there can be some blurring due to movement.
One more tip: if you wear deodorant, antiperspirant, powders, or lotions in the underarm or breast area every day, spend a little extra time in the shower cleaning those areas on the morning of your mammogram. “The goal is to have no particles left behind on the skin,” says Dr. Keating.
And what if you forget and wear deodorant to your mammogram by mistake? Speak up when you check in and ask for help. Many imaging centers provide cleansing cloths to help you remove any product residue before your mammogram. If you don’t say anything, you risk getting called back for more studies.
“Don’t cancel if you simply forgot and did your normal routine,” Dr. Keating says. “Just make sure you ask for towelettes and carefully clean the entire breast and under the axilla (underarms).”
Learn more about calcifications.
Written by: Kristine Conner, contributing writer
Reviewed by: Marcia Boraas, M.D., FACS, associate professor of surgical oncology at Fox Chase Cancer Center, Philadelphia, PA; Breastcancer.org professional advisory board member