Armpit Tattoos Are the Most Surprising Trend of the Summer—But Are They Safe?

You can get a tattoo pretty much anywhere on your body, and the underarm ink trend is living proof. Intricate tats in this sensitive area have been popping up all over Instagram lately, and it’s hard to stop scrolling through the #armpittattoo pics. But we couldn’t help but wonder, is it safe to get inked in your armpit?

To find out more, we spoke with Dr. Pauline Jose, a clinical instructor in UCLA’s Department of Family Medicine. It turns out there is one real risk associated with prettied-up pits, and it has to do with your lymph nodes: “Tattoo pigments travel through the lymphatic system,” Jose explains. “Since lymph nodes are abundant in the armpit area, [an armpit tattoo] can pigment those lymph nodes, and mimic—or confuse—a cancer diagnosis.”

Armpit tattoos can be especially problematic for people who develop melanoma, she says, because pigmented lymph nodes can look like metastasis. “All those pigmented lymph nodes, and the skin supplied by them, may need to be biopsied when looking suspicious.”

MORE: You Asked: Are Tattoos Bad For You?

Health.com: 7 Things Every Woman Should Know About Her Skin

If you’re considering a tattoo, the armpit isn’t the only body part to avoid. Moles should never be inked over, because doing so can make it harder to detect any changes that could be a sign of skin cancer. And getting a tattoo near your eyes is also a bad idea, since the ink can pigment the eyes, says Jose.

With any tattoo, it’s important to remember that ink is a foreign object in the body—and your body may react to it with inflammation, pain, itching, or in other ways that can be heard to predict. If you have an autoimmune condition, or if you experience many allergic reactions to food and medications, “it may not be a good idea to get inked,” says Jose.

On a brighter note: Infections from unsanitary tools or facilities are rare these days, because tattoo parlors practice universal precautions. If you’re planning to get a tattoo, just be sure to avoid parlors that use heavy metal-based inks, says Jose.

This article originally appeared on Health.com