Eucrisa is not a steroid. It belongs to a completely different drug class called phosphodiesterase 4 (PDE4) inhibitors, and its mechanism has no relationship to corticosteroids. This distinction matters because it means Eucrisa doesn’t carry the same risks that make many people cautious about long-term topical steroid use, particularly skin thinning.
What Eucrisa Actually Is
Eucrisa (crisaborole) is a topical ointment approved by the FDA for mild to moderate atopic dermatitis (eczema) in patients 3 months of age and older. It was the first topical PDE4 inhibitor to reach the market, gaining approval in December 2016. The active ingredient is a boron-containing compound that works through an entirely different biological pathway than steroids.
Where topical steroids suppress the immune system broadly by mimicking cortisol, Eucrisa takes a more targeted approach. It blocks an enzyme called phosphodiesterase 4, which regulates a signaling molecule inside immune cells. When PDE4 is overactive, it amplifies inflammatory pathways involved in eczema, including several types of immune responses that drive the redness, swelling, and itching characteristic of flare-ups. By dialing down that enzyme, Eucrisa reduces inflammation without interfering with the body’s cortisol system.
Why the Steroid Question Matters
Topical corticosteroids have been the go-to eczema treatment for decades, and they work well. But long-term or frequent use, especially on sensitive areas like the face, eyelids, or skin folds, can cause skin thinning (atrophy), visible blood vessels, stretch marks, and in rare cases, suppression of the body’s natural hormone balance. These risks make many patients and parents of young children wary of using steroids continuously.
Because Eucrisa works through PDE4 inhibition rather than cortisol pathways, it does not carry these steroid-specific risks. There is no concern about skin thinning or hormonal suppression with Eucrisa, which makes it a practical option for areas where steroids are used cautiously, or for people who need ongoing maintenance treatment.
How Well It Works
Eucrisa’s effectiveness is more modest than potent topical steroids. In two large phase 3 trials involving over 1,500 patients, about 32% of people using Eucrisa achieved clear or almost clear skin with meaningful improvement after 29 days, compared to roughly 18–25% using the vehicle ointment alone. When looking more broadly at anyone reaching clear or almost clear skin, about half of Eucrisa users hit that mark versus 30–41% on the vehicle.
These numbers reflect its positioning for mild to moderate eczema rather than severe disease. For people with stubborn or widespread flares, topical steroids or other prescription options are typically more effective. Eucrisa fills a role for those who need something beyond moisturizers but want to avoid steroids, or who need a longer-term option without steroid-related concerns.
Side Effects and Long-Term Safety
The most common side effect is a burning or stinging sensation where you apply it. This affects a small percentage of users and, in most cases, resolves within a day. It can be uncomfortable enough that some people stop using it, but it tends to improve with continued use.
A 48-week safety study found that Eucrisa maintained a reassuring profile over extended use. About 10% of patients experienced treatment-related side effects overall, with the most common being eczema flares themselves (3.1%), application-site pain (2.3%), and application-site infection (1.2%). The vast majority of reported events, over 93%, were considered unrelated to the medication. Only 1.7% of patients discontinued the long-term study due to side effects. Most adverse events were mild or moderate in severity.
How to Use It
Eucrisa is applied as a thin layer twice daily to affected skin areas. It’s a topical-only ointment, so it should not be used near the eyes, mouth, or internally. If someone else applies it for you, they should wash their hands afterward. You should also wash your own hands after application unless you’re treating the skin on your hands.
The ointment is approved for adults and children as young as 3 months old, making it one of the few non-steroidal prescription options available for very young patients with eczema. Safety and effectiveness have not been established for infants younger than 3 months.
Where Eucrisa Fits in Eczema Treatment
Eucrisa occupies a specific niche. It’s not a replacement for topical steroids in every situation, and it’s not strong enough for moderate-to-severe eczema on its own. Its value lies in being a steroid-free prescription option for mild to moderate cases, for use on sensitive skin areas where steroids carry higher risk, or as a maintenance treatment between flares when you want to avoid prolonged steroid exposure. For parents concerned about putting steroids on a toddler’s face or for adults managing chronic low-grade eczema, it offers a genuinely different approach rather than just a weaker version of the same thing.