What is an ingredient I should look for when searching for acne products for sensitive skin?

Retinol. In general, I recommend my patients with sensitive skin to wash with cetaphil facial cleanser, and use a retinol containing product nightly such as roc night cream. Once your skin is used to this regimen, you might consult with your doctor to begin a prescription regimen that includes a tretinoin, topical antibiotic and benzoyl peroxide. Sometimes oral regimen is needed for clearance.
A few options. For over the counter methods try using products that have benzoyl peroxide, salicylic acid, alcohol, and acetone. For prescription treatments you may be prescribed antibiotics, retinoids or vitamin a derivatives, azelaic acid, oral contraceptives, or spironolactone. Always ask a dermatologist about the possible affects and the risks vs benefits of each treatment. Make sure it's best for you.