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').
Use of methylene blue for endoscopic tattoo has been associated with vascular necrosis, mucosal ulceration, mural necrosis, extramural fat necrosis and inflammatory changes in the colon. Injection of methylene blue into joint space has resulted in effusion in the treated joint. Hyperbilirubinaemia has been reported in infants only.