Dermatological features

The dermatological manifestations of type I neurofibromatosis include:

• cafe-au-lait spots:
  • six or more of 0.5 cm in diameter is characteristic
  • usually develop during the first year of life but may be present from birth
    
    
• Crowe's sign:
  • bilateral axillary and inguinal freckling
    
    
• cutaneous neurofibromas:
  • develop in late childhood
  • soft, sometimes pedunculated
  • appear to be "button holed" through the skin
  • may progress to become plexiform neurofibroma, mollusca fibrosa or elephantiasis neurofibromatosa.
  • Some lesions may become very large.