CONGENITAL INDIFFERENCE TO PAIN *

T H E condition spoken of as "congenital indifference to pain " is a rarity often discovered by chance. In the case of a child, the parents may even-tually realize that a long series of injuries and illnesses has occasioned none of the suffering which would ordinarily have been expected. The subjects of congenital indifference to pain—who are in no way mentally retarded, hysterical or psychotic—present no objective anomaly of sensation. They can detect, identify and localize pinpricks, and can distinguish quite minor differences in thermal contacts. Sometimes the subject is also insensitive as to smell and taste. Furthermore, itching often lies outside the subject's sensory experience. Neurologic examination yields no abnormality other than sluggish or absent corneal responses. Scars and arthropathies may bear witness to earlier painless traumata. Experimental interventions which might be expected to give rise to pain provoke neither a verbal protest nor mimic responses, such as wincing, nor yet any vegetative reflex activity. Congenital indifference to pain is a specific entity which needs to be dis