Even celebrities get a blemish now and then, so Allure chatted with a dermatologist to the stars on how red-carpet beauties get their skin in tip-top shape.

Waking up to a monster pimple is problematic for anyone. But for the celebrities attending this weekend's Academy Awards, grinning and bearing it isn't an option. That's when they call L.A.–based dermatologist Dr. Harold Lancer. Lancer, who tends to the likes of Ryan Seacrest and Victoria Beckham, keeps his office open for frantic calls in the hours leading up to the awards show. "It would be extremely uncommon not to see people on Saturday or Sunday," he says. "Stuff always happens — they have an irritation, or they have a costume change and something is now showing on the back that has to be dealt with." We spoke with the dermatologist to find out how he prepares A-list skin for its biggest night of the year. Get Dr. Lancer's tips when you keep reading.

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How early do people start coming to you before the Oscars?
No one becomes a patient the night before. They're all on skin care routines and coming in once a month for micropolishing. But a month before, the treatments get a bit more intense.

What does your pre-Oscars treatment entail?
One month out, patients will come in once a week for gentle micropolishing followed by five to ten minutes of red or blue LED light treatments. The blue is for oily or acne-prone skin and the red is for skin that needs plumping and soothing. Then two weeks out, they'll get two different facials a week—either a 'vegan facial' with algae stem cells, or a stem cell or placenta stem cell facial that are sheep based. When applied topically, they're nourishing and increase collagen production. They'll also do a toning or lifting procedure, like Viora, to firm and lift the eyebrows, jaw, and neck.

Do you put the celebrities on a special diet?
We reduce carbs and eliminate salt and caffeine. Sugars and carbohydrates will suck water out of the dermis and make the skin look lackluster and flabby. If you watch the show, no one is eating anything, because the prepared food is full of salt and carbs. And they're not drinking alcohol, because it's dehydrating. We get them off all that.

What do you do if a blemish does pop up the day before, or — heaven forbid — the day of?
If we wait for a zit to treat itself, with the stress hormones, it won't be gone until Tuesday. We'll drain it and ice it immediately. The swelling goes down in about 30 minutes.

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