Pregnant Mandy Moore is battling a skin condition she says is the "pits" as she awaits the arrival of her third child

She said in an Instagram post that showed her with a skin device: "Pregnancy melasma is the pits."

The gadget she was using in the photo was a Lyma Laser, billed as giving "unrivalled results" on "signs of aging, wrinkles, rosacea, pigmentation, skin elasticity and scarring", according to its makers.

Mandy added in her update about her condition: "I heard @lymalife can help."

Experts say melasma is a harmless skin condition that causes brown or blue-grey patches or freckles on the body, which most commonly appear on people's cheeks, nose, chin, upper lip and forehead.

It is common among pregnant women.

Announcing her third pregnancy on Instagram in May, Mandy said in a joint post with her husband: "Sometimes life imitates art. The third in our own Big Three coming soon."

Mandy was referring to the three children her character has in 'This is Us'.

She recently told People her latest pregnancy is different from her previous two as she is "chasing two wild toddlers" around at the same time.

Mandy has previously opened up about how she suffered eczema that was so severe it left her wanting to tear her flesh off,

She told Refinery29 about being diagnosed in 2019"I thought, okay, I'm working a lot, wearing a lot of makeup and prosthetic makeup, maybe it has something to do with that.

"(I thought) maybe I'm having some sort of allergic reaction. But when I threw the kitchen sink at it and the symptoms just kept persisting, I was like, it's time to go to the dermatologist, where I was diagnosed.

"I started noticing red, patchy, peeling spots on my face. I feel lucky that I'm in a line of work where things can get covered, but that doesn't take away the discomfort.

"I was constantly thinking about it while I was on camera. I wanted to tear my face off. It itched so bad."