[Severe hypernatremic dehydration disclosing Netherton syndrome in the neonatal period].

Background: Netherton's syndrome is characterized by ichthyosis, trichorrhexis invaginata and other air shaft anomalies, and atopic diathesis. The ichthyosis is present at birth and can be complicated by hypernatremic dehydration.

Case Report: Adrien was the first child of non-consanguineous parents. His birth weight was 3,110 g. Ichthyosis was present at birth and the diagnosis of Netherton's syndrome was subsequently confirmed by skin biopsy. He was admitted to intensive care at the age of 4 days for a 20% loss of weight and dehydration. His blood chemistry was: Na+ = 192 mmol/l; K+ = 6.9 mmol/l; Cl- = 136 mmol/l; urea = 21 mmol/l; glucose = 12.1 mmol/l; creatinine = 209 mumol/l; hematocrit = 51%. Urinary analysis gave: Na+ = 113 mmol/l; K+ = 97 mmol/l; urea = 105 mmol/l. Progressive rehydration resulted in normal diuresis 24 hours later and a slow normalization of natremia to 138 mmol/l on day 10. Despite preventive i.v. phenobarbital, he developed convulsions on day 5 when his natremia was 177 mmol/l i.e. after a drop of 0.6 mmol/hour. The convulsions disappeared when he was given phenytoin and placed on respiratory support, but status epilepticus appeared on day 18 with normal natremia. This status epilepticus was not influenced by several antiepileptic drugs and was only cured when the patient was given tetracosactide followed by hydrocortisone plus sodium valproate. Adrien is now 3 years old and is neurologically and mentally normal.

Conclusion: Hypernatremic dehydration can be a complication of neonatal ichthyosis; it may be severe with very high blood sodium concentration. Corticosteroids can be useful for treating persistent convulsions.