Why does benzoyl peroxide burn?

What makes the irritation worse?

Using too much benzoyl peroxide increases side effects without making acne clear faster. Other drying acne treatments, abrasive cleansers and products containing alcohol can add irritation. Lower concentrations may be better tolerated, so start with the lowest available strength. Do not apply benzoyl peroxide to broken or infected skin.123

Irritant contact dermatitis means skin inflammation caused by contact with something irritating, rather than an allergy. It can cause burning, pain and dry, rough skin. People with atopic dermatitis, a type of eczema, have a higher risk of this reaction. Benzoyl peroxide can also cause contact allergy, although this is uncommon. An allergic contact rash often appears 24 to 48 hours after exposure, and previous tolerance does not rule it out.14

What should you do if it burns?

1. 1If your skin is burning now, wash the area with plenty of water to remove remaining product and stop applying more.
2. 2Get prompt medical advice for burning, blistering, swelling or a rash. Do not keep applying benzoyl peroxide through a worsening reaction.
3. 3For mild dryness or slight stinging without a serious reaction, use benzoyl peroxide less often. Speak to a pharmacist or doctor if symptoms bother you or do not go away.

Stop using benzoyl peroxide and seek emergency help for throat tightness, difficulty breathing, feeling faint, hives, or swelling of the eyes, face, lips or tongue. These can be signs of a serious allergic reaction.2

Daily moisturizer can help skin tolerate benzoyl peroxide by reducing dryness and irritation. An acne friendly moisturizer belongs in an acne routine, even if the word moisturizer sounds like it wandered into the wrong aisle. Look for "noncomedogenic", "oil free" or "won't clog pores" on the container. Apply moisturizer after washing to help retain water in your skin.5

How can you use it with less irritation?

Benzoyl peroxide comes in washes and products you leave on, so the word treatment is doing several jobs on the same shelf. Follow the directions for your exact product rather than treating both formats alike.3

1. 1Before first use, apply a small amount to one or two small treatment areas for three days. Continue as directed only if there is no reaction or discomfort.
2. 2Start once daily to see how your skin reacts, following the package or prescription directions.
3. 3For a cream, lotion or gel that stays on, gently wash and pat the skin dry, then apply a small amount.
4. 4For a wash, rinse it off as directed. NHS directions for benzoyl peroxide gel wash specify washing for 1 to 2 minutes before rinsing.
5. 5Avoid scrubbing, drying cleansers and products containing alcohol. Use sunscreen and avoid sunlamps.

Check with a pharmacist or doctor before combining benzoyl peroxide with other acne treatments. Prescription combinations can be appropriate, but the pairing matters: adapalene can be used with benzoyl peroxide, while tretinoin degrades when benzoyl peroxide is present. During pregnancy, benzoyl peroxide can usually be used, but check with your doctor first.13

How long should irritation last?

Common irritation usually improves after a few days or with less frequent use. Acne improvement takes about 4 to 6 weeks. Contact your doctor if acne has not improved by then, and seek help sooner if it worsens. Deep, painful spots or acne causing scars also need medical assessment.236