It’s not only your body that changes during pregnancy — your skin can go through a roller coaster of changes, too. In fact, more than 90 percent of women report having significant skin changes during pregnancy due to the shifts that occur within the body’s endocrinological, immunological, metabolic, and vascular systems while growing a baby, according to a study published in the October–December 2014 issue of the Journal of Family Medicine and Primary Care.

The effect pregnancy can have on the skin varies from woman to woman. Some women might see improvements to their complexion, giving them what many call the “pregnancy glow,” according to the American Pregnancy Association. Others may experience worse symptoms of preexisting skin conditions.

If you do notice your skin start to change, chances are it’s related to eczema, aka atopic dermatitis, a condition marked by red, itchy patches of skin, according to the Mayo Clinic. “Eczema is the most common skin disorder of pregnancy,” says Daniel P. Friedmann, MD, a board-certified dermatologist with Westlake Dermatology in Austin, Texas. It accounts for between 33 and 50 percent of skin issues that develop during this time in a woman’s life, according to the National Eczema Society.

The Link Between Pregnancy and Eczema

Eczema flares are the result of different environmental and internal triggers, and it appears pregnancy is one of them, according to a past study published in The BMJ. This is especially true if you’ve dealt with eczema before. “Women with a history of eczema prior to pregnancy have a significant risk of an eczema flare during pregnancy,” Dr. Friedmann says.

About 20 to 40 percent of women who experience eczema while expecting have had it before, according to the National Eczema Society. For these women, it tends to worsen during the second trimester (Friedmann suspects because of the immunological changes that occur as the fetus grows), though it can occur in the first or third trimesters as well.

Unfortunately, not having experienced eczema before doesn’t mean you’re in the clear — it’s entirely possible for eczema to appear for the first time while pregnant, Friedmann says.

So, why does pregnancy seem to exacerbate eczema symptoms? Blame those shifting hormones. “Eczema symptoms during pregnancy are largely related to the impact of female sex hormones on the immune system,” says Natalie Yin, MD, an assistant professor of dermatology with Columbia University Medical Center in New York City. She explains that during pregnancy, the immune system shifts from a Th1 response to a Th2 response in order to protect the fetus.

These T responses belong to the same family of white blood cells and are major sources of hormone messengers called cytokines. Th1-type cytokines are known for producing proinflammatory responses, while Th2-type cytokines have more of an anti-inflammatory response, according to a study published in Mediators of Inflammation. Friedmann says this slight change in the way the T cells function is associated with an increase in eczema. What’s more, the Th2 response can also worsen asthma and food allergies, Dr. Yin says.

Ruling Out Other Skin Conditions When You’re Pregnant

Complicating the picture is that pregnant women are prone to developing other rashes that might look similar to eczema. For example, pruritic urticarial papules and plaques of pregnancy (PUPPP) is another common pregnancy rash. The itchy, red patches tend to first appear toward the end of pregnancy around stretch marks, though they can spread to the arms, legs, and butt, according to The University of Texas Southwestern Medical Center.

That’s different from eczema because eczema during pregnancy usually appears on the face, chest, or neck, per the aforementioned study in the Journal of Family Medicine and Primary Care. And about 75 percent of the time, pregnancy eczema occurs during the first and second trimesters, according to the BMJ research.

If you’re not sure what type of rash you’re dealing with, consult your dermatologist to have it checked out, Yin suggests.

Tips for Treating Eczema When You’re Pregnant

If you’ve dealt with eczema before, you may have treated it with topical ointments, oral medication, over-the-counter skin-care products, or prescriptions. And while they may have been safe to use before, that may no longer be the case during your pregnancy. The BMJ study notes that pregnant women should avoid some eczema treatment options, such as methotrexate and phototherapy (psoralens plus ultraviolet A).

Yin advises that during pregnancy, it’s best to approach very potent topical steroids, oral steroids, topical calcineurin inhibitors, and oral immunosuppressive agents with extreme caution. If you’re taking one of these drugs, be sure to work closely with your doctor.

Most topical steroids combined with moisturizers can be safe to use during your pregnancy, so long as they’re mild or moderately potent, according to the National Eczema Society. “There is a risk of low birth weight with topical steroid use, but this typically occurs with application of over 300 grams during the entire pregnancy, which is rarely necessary,” Yin says.

Because steroids with a high potency can be dangerous, stay on the safe side by diluting the potent steroid with moisturizer so it’s one part steroid and four parts moisturizer, suggests the National Eczema Association.

Always consult your doctor first to get the okay on any medication you’re taking. “I always recommend patients run products by their board-certified dermatologist or ob-gyn in order to confirm that they are safe to use while pregnant,” Friedmann says. Even if you currently take medication to help with eczema and are not pregnant yet, but plan to become pregnant in the near future, share your plans with your doctor. There may be a minimum amount of time that needs to pass between stopping treatment and becoming pregnant safely, notes the National Eczema Society.

Lifestyle Changes That Can Help Tame Eczema Symptoms

Also keep in mind that many of the eczema treatments involving lifestyle tweaks can be safely incorporated regardless of whether you’re pregnant. “The treatment of eczema during pregnancy begins with warm (not hot) showers and the use of moisturizers and synthetic soaps (no true soaps) in order to limit overdrying of the skin,” Friedmann says.

The Mayo Clinic also suggests:

Applying moisturizer within three minutes of showering
Moisturizing twice a day
Covering the area in bandages
Taking warm baths with baking soda, uncooked oatmeal, or colloidal oatmeal sprinkled in the water
Using a humidifier
Destressing

One Last Thing on Managing Pregnancy Eczema

With your doctor’s guidance, you can weigh the benefits and drawbacks of any medication, as well as be sure you’re getting needed treatment to avoid or manage any skin infection. If you’re seeing a dermatologist for pregnancy eczema, be sure to keep your ob-gyn in the loop, especially about any medication you're taking.

Eczema (Atopic Dermatitis) During Pregnancy: What You Need to Know

The Link Between Pregnancy and Eczema

Ruling Out Other Skin Conditions When You’re Pregnant

Tips for Treating Eczema When You’re Pregnant

Lifestyle Changes That Can Help Tame Eczema Symptoms

One Last Thing on Managing Pregnancy Eczema