The differential diagnosis of hypernatraemia in children, with ...

The Diagnosis of Salt Poisoning Leading to Hypematraemia in Children – September 2009
authors’ speculation that the child had ingested salt as a result of his pica, and considered
that the child had been abused (one beyond reasonable doubt, the other on the balance of
probability). This case therefore should not be used to provide evidence of voluntary salt
ingestion by an otherwise normal child, and has been included in the list of case reports of
non-accidental salt poisoning as a manifestation of child abuse.
There is a second case report in which the authors considered that two otherwise normal
young children spontaneously and voluntarily ingested sufficient salt to cause significant
hypernatraemia. This case from Ohio, USA 220 , published in 1964, relates to two 14-monthold
twin girls who were considered by the authors to have ingested a considerable amount
of rock salt, possibly aided and abetted by an older sibling. Their sodium concentrations on
admission were 179 and 182 mEq/L.
It would be important to be aware that young, otherwise normal children have been
reported voluntarily to ingest salt to this extent. This case was cited in a recent review of
the evaluation of salt poisoning as a “well-described case of voluntary salt poisoning”. 221
Accordingly, this second case report was peer reviewed by the whole panel of 16
paediatricians. Eight disagreed with the authors on the balance of probability, one
disagreed beyond reasonable doubt, and 5 said they could not tell from the publication
whether the authors’ conclusions were correct. Only two agreed with the authors on the
balance of probability. The following points were made:
• This paper was published before the reality of child abuse was recognised, and child
abuse was not discussed as a possible diagnosis
• The toddler who swallows bleach takes a swig and spills most of it. What they do
not do is voluntarily go back for a second helping. It is unlikely that the ingestion
response would be much different for salt
• The social history given in the case report is inadequate. However, there are some
pointers to family stress:
• 3rd pregnancy in a 19-year old mother
• The mother did not visit for first 24 hours after admission
• On a home visit a month after admission a large box of salt was again within easy
grasp of the twins
• Both the twins were undernourished
• At their age, they would be unlikely to have the fine-motor control to ingest large
quantities of salt, and could only have ‘finger-fed’ small quantities
• Neither child had reportedly eaten or drunk for almost 48hr, nor had they vomited;
salt ingestion to cause this degree of hypernatraemia would generate thirst
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