What’s this rash in my folds? Intertrigo.

As warmer weather hits a new set of rashes rolls in… intertrigo, poison ivy, lyme disease and more. We will address all of these as summer progresses.

Intertrigo is the fancy name for a rash in the folds of the skin. It is most often seen under the breasts, abdominal fold, under the arms and in the groin. It is more commonly seen in the warmer spring and summer months.   Intertrigo is generally caused by one of three main things and in all cases is worsened by moisture.

The three common causes of intertrigo include psoriasis, fungus and yeast. Here’s a few ways to tell them apart and treat them.

Fungus is more commonly the cause of intertrigo in the groin. Especially when there is fungus on the feet or toenails, the fungus is often spread to the groin when donning underwear. Fungus is usually a more red brown color, scaly and has an even, smooth border. Fungus is best treated with antifungal creams such as terbinafine or Lamisil. In some case oral Lamisil is required.   I prefer Lamisil cream or its generic form because it is more effect in killing fungus (fungicidal) than other treatments.

Yeast is more commonly seen under the breasts and in the abdominal folds. Yeast tends to have a brighter red, purple color with what we call satellite lesions at the edge. Yeast is best treated with creams such as nystatin or orally with Diflucan.

Psoriasis is the most common missed diagnosis. Psoriasis is usually red with no satellite lesions. Psoriasis can be seen in the gluteal cleft (bottom crack), axilla (underarms), abdominal fold, groin, ears, corners of the eyes and in between the toes. Psoriasis is best treated with very mild topical steroid cream or with a class of non-steroid creams which include Elidel and Protopic/tacrolimus. We commonly use these non-steroid medications because excessive use of topical steroids in thin skinned folds can cause thinning of the skin and stretch marks.

BEWARE the use of topical steroid unless you are POSITIVE that there isn’t any fungus. In MANY cases patients come having treated a rash in the groin or on the feet with topical steroid. Using topical steroid on fungus makes the fungus grow DEEPER in the skin where an antifungal cream won’t work. This is called Majocchi’s Granuloma. (SEE PRIOR POST) . Treatment of Majocchi’s granuloma requires an oral antifungal to treat. This is a very common problem! In many cases, I will treat for fungus first. I do not use any topical steroid until I am POSITIVE that there isn’t any fungus involved.

Finally, I cannot overemphasize the need to keep the folds dry and reduce friction in these areas. I most often recommend a powder called Zeasorb to be used in the folds daily. Zeasorb comes two ways, plain and AF. The AF is anti-yeast and anti-fungal. I usually recommend getting the AF to reduce the possibility of yeast and fungus growing even if it is not the primary problem. For the inner thigh, especially in bathing suit and beach season, I recommend Body Glide to reduce friction. Another great way of reducing moisture and friction is to wear water wicking clothes. During exercise especially I often recommend wearing an under layer that goes all the way into the fold to reduce moisture and friction. NO OVERSIZED, LOOSE -ARMED COTTON T-SHIRTS and baggy shorts. Invest in some UnderArmor or Spanx. You’ll be glad you did!

Want to learn more? – Here’s some articles of interest:

https://www.dermnetnz.org/topics/intertrigo/