Diaper Rash: What’s Causing the Red Rash on Your Baby’s Bum?

I can still remember when my youngest daughter had a particularly intense bout of diaper rash. She cringed and screamed every time I tried to wipe her sensitive bottom, and I started to worry that maybe our new brand of diapers was the culprit. After a few days of this torture, we saw our pediatrician. He recommended a powerful cream to treat eczema and her rash cleared up fast. I was relieved, but surprised that the same eczema my baby was getting on her head and cheeks could actually occur down there, too! But, in fact, it’s pretty common.

So, how can an anxious mama (aka: me!) tell the difference between a run-of-the-mill diaper rash and something more serious?

For starters, treat redness and/or irritation on your baby’s groin, thighs, and/or bum, with a good diaper rash-fighting cream at every diaper change, says Jonathan Blau, MD, a neonatologist with Staten Island University Hospital in New York City. It’s most likely irritation from a wet or poop-filled diaper that your baby has sat in for too long. But, if the rash doesn’t improve within a couple of days — or it gets worse — it’s time to see your pediatrician. One of these culprits may be to blame:

1. Yeast infection
Most stubborn diaper rashes are actually yeast infections, which need to be diagnosed and treated by your pediatrician. Treatment is painless; you’ll apply a cream to your baby’s rear for around 14 days.

2. Allergic reaction
If you’ve recently changed diaper brands, or you’re using a new lotion or soap on your baby, her skin may be irritated. Tell the pediatrician about any new products that you’ve used during your visit.

3. Too tight diaper
If there are dry red papules or bumps along the lines of the diaper elastic, your baby’s diaper might be too snug, which can irritate her skin, says Hugh Gilgoff, MD, a pediatrician in private practice in Brooklyn, New York.

4. Eczema
Some infants have dry, sensitive skin, which can lead to eczema on your baby’s bottom. Your pediatrician can prescribe a special moisturizer or, in some cases, a hydrocortisone ointment, says Dr. Blau.

5. Bacterial infection
Just like yeast infections, bacterial infections are common in the diaper area. Strep — the same bug that causes nasty sore throats — may be the source of your baby’s uncomfortable rash, says Dr. Gilgoff. Another common culprit? Staph.

6. Rare disorder
Finally, there are some rare — very rare — disorders, like psoriasis and a form of cancer called histiocytosis, that your pediatrician can diagnose during a routine exam.
Remember, there’s no need to panic if the rash on your baby’s bum doesn’t go away with an over-the-counter cream (and trust me, I have definitely panicked, so I know what I’m talking about here). Chances are, your doctor will be able to fix the problem fast.

Photo: Getty