Differential Diagnosis for a 3-year-old Female with Unilateral Swollen Mons Pubis without Fever

• Single most likely diagnosis:
  • Ingrown hair or folliculitis: This is a common condition in children, especially in the genital area, where hair follicles can become inflamed due to irritation or infection, leading to swelling and redness.
• Other Likely diagnoses:
  • Contact dermatitis: Irritation from soaps, detergents, or other substances can cause skin inflammation, leading to swelling and discomfort in the genital area.
  • Urine scald: Irritation from urine can cause inflammation and swelling, especially if the child has poor hygiene or is not properly cleaned after urination.
  • Eczema (atopic dermatitis): A chronic skin condition that can cause inflammation and swelling in various parts of the body, including the genital area.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed):
  • Testicular torsion (in males, but can be considered in females with undescended testes): Although less likely in females, it's crucial to rule out this condition, as it requires immediate medical attention to prevent tissue death.
  • Sexual abuse: Although not a medical condition per se, it's essential to consider the possibility of sexual abuse in cases of unexplained genital trauma or swelling, especially in young children.
  • Necrotizing fasciitis: A rare but life-threatening bacterial infection that can cause severe swelling, pain, and skin necrosis, requiring prompt medical attention.
• Rare diagnoses:
  • Hidradenitis suppurativa: A chronic skin condition characterized by recurring, painful abscesses and nodules, typically in areas with apocrine glands, such as the groin.
  • Lipoma or other benign tumors: Although rare, benign tumors can cause swelling in the genital area, and a thorough examination is necessary to rule out these conditions.