Invisible but central: family caregiving as the hidden infrastructure of pediatric PKU-an integrative review.

backgroundPhenylketonuria (PKU) is a rare metabolic disorder requiring lifelong dietary management. While clinical stability hinges on strict treatment adherence, this adherence is largely sustained by unpaid family caregiving, particularly in pediatric contexts. Yet, the lived experience of caregivers remains conceptually underexamined and largely absent from PKU research. This integrative review synthesizes empirical findings on caregiver burden in pediatric PKU and maps a multilevel burden structure that traces its structural, relational, and psychological dimensions.

methodsUsing Whittemore and Knafl's integrative methodology, 31 empirical studies-20 quantitative, 7 qualitative, and 4 mixed-methods-published between 2010 and 2025 were included. Studies were included if they reported on caregivers of pediatric PKU patients; studies focusing on adult patients or without caregiver data were excluded. Thematic coding and axial analysis were applied to identify macro (structural), meso (relational), and micro (psychological) patterns. Methodological triangulation enhanced both analytical rigor and conceptual depth. Studies were identified via a structured PubMed search (updated April 2025) and manual reference screening.

resultsThe review included 31 empirical studies encompassing over 3000 caregivers across 12 countries. At the macro level, key themes included policy fragmentation, the feminization of caregiving roles, and financial precarity. Meso-level patterns revealed persistent emotional asymmetry, compounded relational overload, and hierarchical caregiving dynamics within family systems. At the micro level, caregivers reported chronic emotional depletion, elements of moral injury, and progressive role engulfment. Collectively, these findings outline a relational ecology of care in which emotional and physical caregiving labor operates as a compensatory mechanism for structural and institutional neglect.

conclusionFamily caregivers in pediatric PKU are not peripheral supporters but central contributors to clinical stability. Yet their role remains structurally unsupported and emotionally overburdened. Their psychosocial burden has direct clinical consequences for both the caregivers' health and the children's treatment outcomes. Sustainable PKU care-and by extension, care for other rare and chronic pediatric conditions-requires systemic investment in caregiving infrastructure, not as an act of goodwill, but as a clinical imperative. Findings should be interpreted in light of contextual heterogeneity and limited representation from low-income settings. SYSTEMATIC REVIEW REGISTRATION: Not registered.