Differential Diagnosis for 1-year-old with Developmental Delay, Seizures, and Skin Lesions

• Single Most Likely Diagnosis

  • Tuberous Sclerosis Complex (TSC): This diagnosis is highly likely due to the combination of developmental delay, seizures, and specific skin lesions such as the coarse plaque in the lumbosacral area (possibly a shagreen patch) and pink papules on the nasolabial folds (possibly angiofibromas). TSC is a genetic disorder characterized by the growth of non-cancerous tumors in various parts of the body, including the skin, brain, and organs.

• Other Likely Diagnoses

  • Neurofibromatosis Type 1 (NF1): Although less likely than TSC given the specific skin findings, NF1 can present with developmental delay, seizures, and skin manifestations like café-au-lait spots. However, the presence of a coarse plaque in the lumbosacral area and pink papules on the nasolabial folds is more characteristic of TSC.
  • Epidermal Nevus Syndrome: This condition can involve skin lesions, neurological abnormalities including seizures, and developmental delays. However, the specific pattern of skin lesions described is more suggestive of TSC.

• Do Not Miss Diagnoses

  • Sturge-Weber Syndrome: Characterized by a port-wine stain (which could be considered in the differential for the pink papules, though typically it's a larger, more distinctive lesion), seizures, and developmental delays. Missing this diagnosis could lead to untreated complications like glaucoma and increased risk of stroke.
  • Infantile Hemangiomas with PHACE(S) Syndrome: While less likely given the description, this condition involves large hemangiomas and can be associated with neurological and developmental issues. It's crucial not to miss due to potential complications like high-output heart failure and risk of stroke.

• Rare Diagnoses

  • PTEN Hamartoma Tumor Syndrome: A rare genetic disorder that can present with skin lesions, macrocephaly, and potentially developmental delay and seizures. The skin findings might overlap with those described, but it's a less common condition.
  • Schimmelpenning-Feuerstein-Mims Syndrome: A rare condition characterized by epidermal nevi, often associated with neurological, ocular, and skeletal abnormalities. While it could be considered, the specific constellation of findings in TSC makes it a more likely diagnosis in this case.