One of the main reasons why rosacea is the number one most misdiagnosed skin condition is because people often think that it’s acne.  While these two conditions are two totally distinct and different things, they can happen simultaneously… and are a real pain to try and treat at the same time. Most acne-fighting ingredients tend to irritate rosacea-prone skin, so even though they might help to banish a breakout, they’ll inevitably leave an angry red rash in its place. The answer to this conundrum, according to both a cosmetic chemist and dermatologist? Azelaic acid, aka the must-have ingredient for treating pimples and pustules in sensitive skin types—including rosacea.

Azelaic acid is an active skin-care ingredient that your body naturally produces, says Michelle Wong, cosmetic chemist and founder of LabMuffin, who notes it’s great for “mild to moderate acne and papulopustular rosacea.” She explains that the acid is antimicrobial and helps to reduce a specific bacteria that contributes to acne, yet is gentle enough for sensitive skin to use because of its anti-inflammatory nature.

“Azelaic acid is an FDA-approved [ingredient], and used in prescription form to treat the bumps and pus pimples of rosacea,” says Joshua Zeichner, MD, a board-certified dermatologist in New York, who adds that the ingredient also helps to block abnormal pigment production, so it can “even skin tone and brighten dark spots” as an added perk.

Also helpful for both acne and rosacea is the ingredient’s ability to reduce inflammation. According to Wong, azelaic acid serves an anti-inflammatory double-whammy by “reducing inflammatory chemical messengers,” and “acting as an antioxidant to help reduce inflammation-causing free radicals.” Topically, it also helps prevent clogged pores by reducing “hyperkeratinisation,” which happens when skin cells turnover really quickly and cause blackheads. It does all of this gently, and with fewer side effects than more traditional acne-fighting ingredients like tretinoin or benzoyl peroxide, which means it’s a must-have in your arsenal if you’ve got rosacea. Try products like The Ordinary Azelaic Acid Suspension 10% ($8) or PCA Skin Acne Gel ($50), and be sure to moisturize after you apply. You’ll be well on your way to a happier, breakout-free complexion.

BTW, here’s what skin experts say are the secrets to treating closed comedones, those tricky under-the-skin pimples. And this is what to know about whether acne is genetic or not.