Look for non-comedogenic products, which are less likely to cause blackheads (called open comedones) or whiteheads (closed comedones). The word -hypoallergenic- on product labels indicate that they are unlikely to cause allergic reactions. However, since no product is non-comedogenic and non-allergic for everybody, it is a good idea to carefully test any new product on a small area of your own skin before using it regularly – this is highly recommended if you have sensitive skin. Also, keep in mind that signs of a contact allergy do not necessarily appear immediately after exposure. It can take up to 10 days for symptoms to surface. If you suspect that you have developed a persistent reaction to an unknown substance or allergen, ask your doctor about patch testing to narrow down the cause. Applying a moisturizer can help by calming inflammation and providing a protective barrier, but make sure you choose one without potentially sensitizing ingredients such fragrances and unnecessary additives.