PAH is a rare disease in children, however, it is a severe condition that requires careful and constant management. Although there are many similarities between adults and children with PAH, there are also important differences.
All etiologies of PAH have been described in the pediatric patient population, but PAH most commonly presents in children as either idiopathic PAH (IPAH), heritable PAH, or PAH associated with congenital heart disease (PAH-CHD). However, PAH-CHD is much more commonly present in pediatric patients than in the adult patient population. This is important because although different types of PAH are largely treated with the same drugs, they are managed in a different manner. Patients with different etiologies may respond to treatment in different ways.
Dyspnea, fatigue, and failure to thrive are common symptoms in children with PAH, and syncope is also more frequently observed in children than in adults. For infants with PAH a poor appetite, lethargy, diaphoresis, tachypnea, tachycardia, and irritability are often observed.
PAH is a severe, progressive disease which can rapidly deteriorate if left untreated. This is particularly true in children with PAH, who have a median survival of 10 months if they are not treated, compared to a median survival of 2.8 years for adults.
As a result of this poor prognosis, and because most pediatric PAH patients (77%) present when they are already in a more advanced stage of the disease World Health Organization Functional Class III (WHO FC III), the treatment and management of children has to be carefully considered.