Hi there,
Few common side effects of Benzoyl peroxide are peeling and flaking, redness and irritation, itching etc. Azelex can cause burning,tingling,dryness,rash and stinging. You can take precautions to lessen your chances of developing these side effects by applying a thin film and following the usage directions and do not use more than recommended .You should always start with a lower concentration first, and move up if needed. Using higher percentages may increase your chance of developing side effects. If the symptoms are severe or persistent consult a dermatologist. He/she may suggest other treatment options.
Best luck and regards!