Milk of magesia as a topical treatment has been reported to reduce both redness and inflammation associated with acne.

LA Times Article

Affecting more than 14 million American, rosacea (roz-ay-sha) is often mistaken for common acne. This skin affliction — which affects people of all ages — causes redness on the cheeks, nose, chin or forehead. In many cases, small visible blood vessels, red bumps or pimples may appear on the face.

 http://capitalnews9.com/content/health/118522/dealing-with-rosacea/Default.aspx