The anti-inflammatory and anti-bacterial properties of arnica make it desirable as an important ingredient in many soothing skin creams and lotions. Arnica has been traditionally used to help minimise the soreness of bruises, as well as strained and sprained muscles and joints. It also has anti-bacterial properties. Studies have shown that arnica may possibly help reduce the growth of the bacterium Staphylococcus aureus, which is responsible for many skin infections. As a result, arnica is sometimes included in formulas of topical applications to help reduce the appearance of bruises, soothe skin in general and promote faster healing of skin infections. Strangely for a soothing ingredient, the active element in the additive arnica is the organic compound helenalin, which itself causes skin irritation when it comes into contact at full strength. When used in topical creams and lotions, however, it is formulated at a much lower, but still effective, concentration.