Differential Diagnosis for 4 Year Old with Thinning Hair

• Single Most Likely Diagnosis
  • Alopecia Areata: This is an autoimmune condition that leads to patchy hair loss and is common in children. It often presents with well-defined bald patches and can be associated with other autoimmune diseases.
• Other Likely Diagnoses
  • Tinea Capitis (Ringworm of the Scalp): A fungal infection that causes hair loss, often accompanied by redness, itching, and scaling of the scalp.
  • Telogen Effluvium: A condition that can be triggered by stress, fever, or nutritional deficiencies, leading to excessive hair shedding.
  • Nutritional Deficiencies (e.g., Iron, Zinc, or Biotin deficiency): These can lead to hair loss, especially if the child has a poor diet or certain medical conditions.
• Do Not Miss Diagnoses
  • Congenital Syphilis: Although rare, it can cause hair loss among other symptoms, and missing this diagnosis can have severe consequences.
  • Hypothyroidism: Hair loss can be a symptom of hypothyroidism, and early diagnosis is crucial for treatment and preventing long-term effects.
• Rare Diagnoses
  • Trichotillomania: A psychological disorder where the child pulls out their own hair, which can be a sign of underlying emotional issues.
  • Loose Anagen Syndrome: A rare condition where the hair is easily pulled out, often due to a defect in the hair follicle.
  • Hair shaft abnormalities (e.g., Monilethrix, Trichorrhexis nodosa): These are rare genetic conditions that affect the structure of the hair shaft, leading to breakage and thinning.