Differential Diagnosis for Ulcerated Erosions at the Corners of the Mouth in a 7-Year-Old

• Single Most Likely Diagnosis
  • Angular cheilitis: This condition is characterized by inflammation of the corners of the mouth and can lead to ulcerated erosions. It is common in children and can be caused by a variety of factors including vitamin deficiencies, oral habits, or infections.
• Other Likely Diagnoses
  • Herpes simplex virus (HSV) infection: HSV can cause oral lesions, including those at the corners of the mouth. The presence of vesicles or ulcers in this area could suggest an HSV infection.
  • Impetigo: A bacterial infection of the skin that can cause erosions or ulcers, including at the corners of the mouth.
  • Allergic contact dermatitis: An allergic reaction to substances like food, cosmetics, or metals can cause skin irritation, including at the corners of the mouth.
• Do Not Miss Diagnoses
  • Acute lymphoblastic leukemia (ALL): Although rare, ALL can present with oral manifestations, including ulcers or erosions at the corners of the mouth, due to thrombocytopenia or leukemic infiltration.
  • Inflammatory bowel disease (IBD): Conditions like Crohn's disease or ulcerative colitis can have extraintestinal manifestations, including oral lesions.
  • Immunodeficiency: Conditions that impair the immune system, such as HIV/AIDS, can increase the susceptibility to infections that cause oral lesions.
• Rare Diagnoses
  • Histoplasmosis: A fungal infection that can cause oral ulcers, including at the corners of the mouth, especially in immunocompromised individuals.
  • Langerhans cell histiocytosis: A rare disorder that can cause a variety of symptoms, including oral lesions.
  • Stevens-Johnson syndrome: A severe skin and mucous membrane disorder that can cause oral lesions, although it is more commonly associated with widespread skin and mucosal involvement.