What Causes Cracks or Sores at the Corners of a Child’s Mouth?

“Angular cheilitis” (commonly referred to as “cracked mouth corners”) is the medical term for inflammation at the corners of the mouth. It may affect one or both sides. Initially, the skin–mucosa junction at the oral commissure appears pale or whitish; subsequently, the affected area becomes eroded and softened. Opening the mouth causes irritation and pain, progressing to ulceration, fissuring, and bleeding. Secondary infection is common, and small pustules or crusts may form—often accompanied by discomfort that impairs speaking and eating.

What Causes Angular Cheilitis in Children?

1. Nutritional Deficiency

A common underlying cause is deficiency of trace elements—most frequently zinc. Zinc plays a vital role in stimulating appetite and enhancing immune function. Zinc deficiency leads to immunosuppression and manifests clinically in various ways, including angular cheilitis. For definitive diagnosis, it is advisable to consult a healthcare provider for serum trace-element testing.

2. Infectious Factors

Angular cheilitis in children may result from bacterial, fungal, or viral infections. The most common pathogens include Candida albicans and streptococci. Due to their relatively immature immune systems, children are more susceptible to such infections, thereby increasing their risk of developing angular cheilitis.

3. Poor Oral Habits

During late autumn and early winter, low humidity often causes dryness and cracking of the lips and surrounding skin. Some children habitually lick their lips when they feel dry. However, in dry weather, saliva evaporates rapidly, exacerbating dehydration and ultimately leading to lip fissures and inflammation.

The above outlines the primary causes of angular cheilitis in children. We hope this information proves helpful.