Various conditions can lead to irritated, red skin. Causes can range from a temporary sensitivity to a chronic skin problem. Common culprits of red skin or red spots include: 1  Dry skin. 2  Sunburn. 3  Rosacea. 4  Acne. 5  Allergic contact dermatitis. 6  Eczema (atopic dermatitis).
Methylene blue is a component of a frequently prescribed urinary analgesic/anti-infective/anti-spasmodic known as Prosed, a combination of drugs which also contains phenyl salicylate, benzoic acid, hyoscyamine sulfate, and methenamine (aka hexamethylenetetramine and not to be confused with 'methanamine').
Methylene blue will most likely cause your urine or stools to appear blue or green in color. This is a normal side effect of the medication and will not cause any harm. This medication can cause you to have unusual results with certain medical tests.