PDE-4 Inhibitors for Atopic Dermatitis

Medically Reviewed by Stephanie S. Gardner, MD on February 22, 2022
3 min read

When you or your child has atopic dermatitis, your doctor might prescribe a topical medication (the kind you apply to your skin). Topical steroids are widely used. But sometimes these don’t work well enough. Or maybe you’re discouraged by the side effects.

In that case, your doctor can try another type of prescription ointment. One of the newer choices is a phosphodiesterase-4 (PDE-4) inhibitor. This type of drug works by blocking an enzyme involved in the inflammation process. It has a low risk of side effects, and is safe to use on babies 3 months and up.

PDE-4 enzymes produce proteins called cytokines, which signal your immune system to get to work. In people with healthy skin, this helps protect against harmful substances. But if you have atopic dermatitis, your PDE-4 enzymes are overly active. They produce too many cytokines.

This leads to inflammation, and the red, itchy skin of atopic dermatitis. By blocking PDE-4, PDE-4 inhibitors inhibit, or hinder, this process.

The FDA has so far approved one topical PDE-4 inhibitor, crisaborole (Eucrisa) for atopic dermatitis. It’s available as an ointment in a 2% concentration. The ointment not only delivers the medication, but helps your skin stay moisturized.

Crisaborole is FDA-approved to treat mild to moderate atopic dermatitis in both adults and kids. (Atopic dermatitis is classified as mild, moderate, or severe depending on how much of your skin it affects, and how bad your symptoms are.)

This medication can be used by people of any ethnicity or skin tone. You can use it over longer periods than topical corticosteroids. And, unlike corticosteroids, you can use it on delicate areas like your face, eyelids, and skin folds.

But crisaborole is more expensive than topical corticosteroids. In fact, a month’s supply can cost more than $700 (without insurance). So your health insurance may not cover this medication unless you’ve tried other treatments first.

You might get approval only if:

  • You’ve tried at least two topical corticosteroid ointments, but they didn’t improve your symptoms
  • You couldn’t tolerate the side effects from other medicines you tried
  • Your eczema is in a sensitive body part where you can’t use other medicines
  • Your child is younger than 3 months, so can’t use medicines containing calcineurin inhibitors

If you’re pregnant, breastfeeding, or trying to get pregnant, talk to your doctor about whether a topical PDE-4 inhibitor is safe for you. Also, let your doctor know what other medications and supplements you’re taking. Some may interact with crisaborole.

It’s important to carefully follow your doctor’s instructions for using topical PDE-4 inhibitor. Usually, you’ll apply a thin layer of the ointment twice a day to areas where you have atopic dermatitis symptoms.

For best results, put it on as soon as you get out of a bath or shower. Wait 15 minutes before using moisturizer. Wash your hands after applying it, unless you’re using it to treat atopic dermatitis on your hands.

If you accidentally skip a dose, apply the ointment as soon as you remember to. If it’s almost time for your next dose, just stick to your regular schedule. Don’t use extra ointment to make up for the missed dose.

It may take anywhere from a few days to a few weeks for the medication to fully work. In some studies, people saw improvement in their atopic dermatitis inflammation in as little as 2 days after starting crisaborole. About a third of study participants had clear or almost clear skin after using the ointment twice a day for 28 days. Ask your doctor when you might expect to see results.

These medications work best when you also follow your doctor’s advice about bathing, moisturizing, and managing triggers.

You might use crisaborole steadily, or on and off as needed to treat flare-ups.

Rarely, the ointment can make your skin burn or sting just after you put it on. But keeping it cold can reduce that feeling. Keep the tube in your refrigerator if this happens to you.

In studies of crisaborole, a few people got skin infections or noticed that their skin symptoms got worse. Tell your doctor if you have these side effects.

It’s also possible to have an allergic reaction to this medication. Stop using it if you get hives, bad itching, swelling, or redness.