A patient with autosomal recessive Pseudohypoaldosteronism Type 1 (arPHA1) may develop a pulmonary syndrome caused by an increase in free lung water.


Patient selection: child with autosomeal recessive pseudohypoaldosteronism Type 1


Mechanism: a systemic loss of function in the epithelial sodium channel (ENaC) results in an inability to resorb free water in the lungs


The onset of pulmonary symptoms usually start during infancy. The episodes become less frequent and severe over the age of 5 years.


Clinical features - recurrent episodes with:

(1) chest congestion

(2) coughing

(3) wheezing and crackles

(4) tachypnea


Laboratory findings:

(1) may be negative for pulmonary infection (negative Gram stain, cultures, etc)

(2) increased sodium in sweat and saliva


Differential diagnosis:

(1) cystic fibrosis

(2) immunodeficiency

(3) asthma


To read more or access our algorithms and calculators, please log in or register.