Signs are more likely to have been due to underlying medical condition

EDITOR—Heger et al remind readers that high doses of morphine may have paradoxical effects.1 We are surprised, however, at the choice of patient they use to illustrate this lesson.

The diagnosis of pain in an infant depends solely on the observation of his or her behaviour.2 It is particularly difficult to diagnose pain, let alone characterise it as allodynia, in a 9 month old infant with considerable neurological deficit and raised intracranial pressure. The authors attempt to justify the diagnosis of allodynia in just such a patient. Furthermore, high dose morphine is well reported as a cause of rigidity, catalepsy, akathisia, and myoclonus, which must add to the difficulty of interpreting pain on the basis of observation alone.3 Two inconsistencies in the case history undermine the speculative …