Differential Diagnosis for a Toddler with a Black Scab in the Belly Button

• Single Most Likely Diagnosis
  • Umbilical granuloma with dried-out secretion: This is a common condition in toddlers where the umbilical stump doesn't heal properly, leading to a small, usually harmless growth that can appear as a black scab.
• Other Likely Diagnoses
  • Omphalitis: An infection of the umbilicus, which can cause discharge, redness, and sometimes a black scab-like appearance due to dried pus or debris.
  • Umbilical dermatitis: Irritation or allergic reaction around the belly button, potentially causing a scab-like lesion.
• Do Not Miss Diagnoses
  • Malignancy (e.g., umbilical metastasis): Although extremely rare, a black scab in the belly button could potentially be a sign of a metastatic tumor, making it crucial not to miss this diagnosis.
  • Infected umbilical hernia: If the toddler has an umbilical hernia that becomes infected, it could present with signs similar to a black scab, including redness, swelling, and discharge.
• Rare Diagnoses
  • Umbilical pilonidal sinus: A rare condition where a small pit or tunnel forms in the skin near the belly button, potentially leading to infection and a scab-like appearance.
  • Foreign body reaction: If the toddler has inserted an object into the belly button, it could cause a reaction leading to a scab-like lesion.