Does your baby have an itchy rash on his legs? Get the inside scoop on what could be causing the red bumps and scales. Understand what baby rash looks like and what the best treatment is for soothing irritated skin.

By Mona A. Gohara, M.D.
Updated January 28, 2020
big baby legs
Credit: Getty Images

Your baby's chubby little legs can be magnets for marks, rashes and other alarming changes. But don't fret: Many of those little bumps and breakouts go away on their own, and most of them aren't serious at all. Learn the ins and outs of some common rashes so you can have a leg up on what is going on with those little gams.

Eczema (Atopic Dermatitis)

What is it? Nearly 20 percent of young kids develop atopic dermatitis, AKA eczema, where dry, cracked skin becomes a big red rashy mess. You can blame a defect in a protein called filaggrin, which normally protects skin and helps it retain moisture and keep out irritants. When filaggrin is deficient, water easily evaporates from skin resulting in dryness and cracks, allowing outside irritants need to settle in and wreak rashy havoc. Common triggers include wool, heat, or the chemicals in soaps, fragrances, lotions, and detergents. It usually starts in infancy, with more than half of patients developing symptoms in the first year of life and most developing symptoms before age 5.

What does it look like? Atopic dermatitis creates pink or red patches of dry skin that are likely to scale and ooze. Eczema patches are also extremely itchy—if it doesn't itch, it isn't this.

Where will it show up? The most common location for eczema is behind the knees, although it can occur anywhere. Look for similar skin changes on the face, scalp, and arm creases.

How do I take care of it? At bath time, keep it short, warm (not hot), and sweet. Use mild non-soap cleansers with a neutral pH. Pat, do not rub, the baby with a towel, and within minutes of bathing, lube her up with a fragrance-free ointment or cream (Aquaphor works wonders). If the skin is inflamed, try putting a cup of oats in the water to soothe irritation. Always remember to avoid triggers such as fragranced products, wool, and overheating. For severe flares, Latanya Benjamin, M.D., clinical assistant professor of dermatology at Stanford University, recommends gentle, yet strong enough topical corticosteroids for the active (red, itchy, rough) patches. "It's best to simultaneously treat the itch. Usually, this is accomplished with an oral antihistamine." Do not be surprised if your doc suggests bleach baths to reduce the risk of any infection.

Heat Rash (Miliaria)

What is it? Miliaria occurs in babies when their developing sweat glands get clogged. This is a very common condition, especially in hot, humid weather or with overbundling in the first few weeks of life.

What does it look like? Tiny pink or clear bumps that can sometimes look like minute blisters.

Where will it show up? You'll find it in sweaty spots, such as the folds of those cute, chubby, thighs, or the top of the leg, under the diaper area. Other prime spots include the neck, chest, and the face (from nursing).

How do I take care of it? The key is keep it to keep it cool—in the environment, clothing, and baths. Lightweight, breathable, cotton onesies alone can melt away miliaria. In stubborn situations a topical cortisone or antihistamine may help things along.

Yeast Infection (Candidiasis)

What is it? Candidiasis is a common yeast infection in babies aged up to 15 months. It usually develops in warm moist areas of the skin (such as under the diaper). Babies taking antibiotics and breastfed babies whose mothers are on antibiotics are also more susceptible to these infections. That's because antibiotics kill the good bacteria in the body that keep yeast in check.

What does it look like? You'll see very red patches, with small satellite papules or pustules a little further away from the main area.

Where will it show up? The top of the thigh near the diaper area is the most common place to see this. The bottom is almost always affected.

How do I take care of it? Dr. Benjamin recommends an antifungal yeast cream twice a day, especially in the thigh creases. "Use a good barrier cream containing zinc oxide and layer it on frequently like frosting a cake at each diaper change," says Dr. Benjamin. "You should not be able to see any red skin throughout the day." Also, check your baby's bottom often, clean it thoroughly with changes, and give the area a chance to dry completely before putting on another diaper. Put diapers on with a little give so that air can circulate around the skin.

Molluscum Contagiosum

What is it? Molluscum contagiosum is caused by a pox virus. It may sounds scary, but breathe easy: molluscum has no harmful consequences except for cosmetic aggravation and the po-tential for spread to other family members. This generally isn't an issue affecting newborn skin -- it's more likely to affect those over the age of one.

What does it look like? You'll see painless, skin-toned, pink, or pearly bumps which may have a visible core or dell in the center. Usually they hang in a gang!

Where will it show up? Molluscum can occur anywhere on the legs, but they like to stay cozy in warm, dewy creases, especially behind the knees.

How do I take care of it? Your child's immune system will naturally get rid of molluscum—though it may take months. If you want to expedite the process, a health care provider can prescribe some creams that help to stimulate the skin's immune response, or they may even use topical, engineered beetle juice to speed things along. (It's painless, and yes, it's beetle juice!) Don't forget that it's contagious, so be especially careful during bath or swim time, and make sure you use separate towels and sheets for kids who have the infection to avoid spreading it.

Hand, Foot, and Mouth Disease

What is it? Hand, foot and mouth disease, also known as cocksackie virus, causes a distinct rash. Babies are most likely to get infected during the spring and summer.

What does it look like? You'll see sore bumps sitting on inflamed, pink surrounding skin.

Where will it show up? The name says it all! But also look for lesions on the hands, upper legs, buttocks, and in the mouth.

How do I take care of it? There's no treatment, other than managing the symptoms by keeping the fever down and ensuring your little patient eats well. (Those mouth sores can make mealtime rough.) Always check with a doctor about additional care.