From the brains behind brains on, this is the moment of um.

Answering those questions that make you go, um, um, um, moment of um comes to you from APM Studios. I'm Stephanie's skin.

Stephanie's dermis, if you want to be scientific. I cover her entire body. She moisturizes me after bath time,

put sunscreen on me in the summer. Sometimes she even scratches me by mistake. But I know she doesn't

mean to. And honestly, sometimes I love being scratched. But you know what I don't love?

Getting rashes.

You know those red bumps on your skin that can be itchy and painful?

In fact, down on Steph's ankle, we've got ourselves a patch of rash right now.

Oh, so itchy.

I wonder what's going on inside of me that's making this happen. How does skin make a rash?

Corinne and Luke were wondering about this too.

It really depends on where the rash is to know how your skin makes it.

My name is Anjali Gantz.

I'm a pediatrician at the Children's Hospital of Philadelphia.

Basically, the skin has three layers.

It has an epidermal layer, a dermal layer underneath,

and then subcutaneous fat.

The top layer, the epidermis,

is a really thin outer layer of skin.

So that's sensitive to external triggers in the environment, things like sun exposure or water or things that might get onto your skin from lotions or products. So if you have a rash on that top layer of skin, it's usually

coming from some external trigger. The next layer of skin is the dermis. So the dermal layer

of skin has a lot of different elements, including blood vessels, sweat glands, things like that.

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