Redness around the mouth may be caused by several factors, including skin allergy or poison ivy. Red flaky skin around the mouth may also be caused by perioral dermatitis or a medical condition known as eczema, which may also cause bleeding sores. Psoriasis, another type of skin condition, may cause redness around the mouth along with flakiness and peeling skin. Some individuals with a skin disorder known as rosacea may experience flare-ups that can cause redness around the mouth, cheeks, and other areas on the face. Mild cases of sunburn may also produce patches of red, dry skin around the mouth.

Skin redness or rash may be limited to the area surrounding the mouth, in which case it may be due to eating a food with high acidic content. Some individuals who eat citrus fruits, such as oranges or lemons, may develop redness around the mouth. This generally causes nothing more than a slight discomfort and possible burning sensation due to the acid levels of the fruit. Redness will usually disappear in a short while, and the skin may be soothed by applying a cream or aloe lotion.

More serious conditions known to cause redness of the face and mouth are eczema, perioral dermatitis, and psoriasis. All of these skin conditions may cause skin peeling or flakiness, dry patches, and redness around the mouth, as well as other areas of the body. Perioral dermatitis specifically afflicts areas around the mouth, causing bumps and itchiness as well. Eczema and psoriasis may cause mild to severe skin inflammation, with eczema developing in infants and very young children more frequently than adults. Treatments for these conditions mostly involve prescription medications from a physician.

Poison ivy, poison oak, or poison sumac often cause intense itching and skin rash on various parts of the body. Redness around the mouth can occur if oils from any of these plants come in contact with skin around that area. When a person walks through poison ivy, poison oak, or poison sumac shrubs or bushes, the caustic oils on the plants may cause a reaction to any part of exposed skin. Inflammation and rash generally will occur, but may be relieved by the use of calamine lotion. Skin that has been exposed to oils from these poisonous plants should be thoroughly washed, and all clothing that has come into contact must be washed to prevent the spread of the rash.