A 13-year-old girl is prescribed benzoyl peroxide 5% gel for acne. Which of the following is a common side effect?

• A. Nausea
• B. Dizziness
• C. Skin dryness and irritation
• D. Photosensitivity

Answer: (C)

When a topical acne treatment is applied, irritation of the skin is a common trade-off for its effectiveness. Benzoyl peroxide works by killing acne-causing bacteria and helping to shed dead skin cells, but it can disrupt the outer skin barrier. This often leads to local dryness, redness, peeling, and a burning or stinging sensation, especially at higher concentrations or during the first weeks of use. To minimize this, start with a small amount, apply it once daily, use a gentle cleanser, and moisturize as needed. Sunscreen can help if the skin becomes more sensitive.

Nausea or dizziness would be systemic effects, which aren’t expected with a topical product. Photosensitivity is typically not a major issue with benzoyl peroxide, unlike some other acne treatments or medications.