angular cheilitis (Revised)

Inflammation of one or both corners of the mouth, that is often red with skin breakdown and crusting. It can be itchy or painful.

(Causes)
• Deficiency of vitamin B2 (riboflavin) in the body: Slows down the metabolism of fats, proteins, and carbohydrates and decreases energy production.
• Candidiasis: With trapped and built up saliva in the corners of the mouth, the warmth and moisture create the perfect conditions for Candida albicans (yeast) to grow and multiply. It also causes diaper rash in babies.
• Iron deficiency anemia

(Treatment)
• Increasing the intake of vitamin B2 and protein (eating foods like eggs, milk, and lean meat) may help reverse it. Moreover, it is imperative to consume foods rich in vitamin B12 (cobalamin), zinc, and vitamin B9 (folic acid) to keep it at bay.
• Topical cream or medication given systemically depending on the underlying cause: Antifungal cream (e.g. nystatin, ketoconazole, clotrimazole, miconazole) for fungal infections (e.g. Candida), antibacterial medication (e.g. mupirocin, fusidic acid) for bacterial infections, and petroleum jelly for other cases.

(Comparison: Locations, causes)
• angular cheilitis: Corner of the mouth. Caused by deficiency of vitamins and candidiasis.
• cold sore: On the lips, the edges of the lips, around and inside the mouth, around the nose, eyes, or genitals. Caused by herpes simplex virus type 1 (HSV-1) and less commonly, type 2 (HSV-2).
• canker sore: Inner surface of the cheeks and lips, tongue, upper surface of the mouth, and the base of the gums. Caused by trauma in the mouth (e.g. biting the tongue or inside the cheek).
• rhagade: Tends to form at areas of motion especially at the angles of the mouth and nose. Caused by bacterial infection, associated with late stages of congenital syphilis.
• impetigo: Around the nose and mouth or on the arms or legs. Caused by group A Streptococcus and Staphylococcus aureus.
• lip licker's dermatitis: Along the perimeter of the mouth. Caused by excessive licking and wetting of the area surrounding the mouth leading to the inflammatory response.