Porphyria attacks in prepubertal children and adolescents.

CONTEXT: The clinical and laboratory features of dominant acute hepatic porphyrias (AHPs) in prepubertal children and adolescents have not been well established. OBJECTIVE: To evaluate clinical and laboratory features of AHPs in prepubertal children and adolescents compared to adults. DATA SOURCES: OVID (Embase Classic+Embase and MEDLINE), Scopus, and Google Scholar. STUDY SELECTION: Studies describing symptomatic children or adolescents (<18 years old) with increased urinary porphobilinogen were included. DATA EXTRACTION: Two reviewers independently extracted the data, with a third reviewer arbitrating discrepancies. RESULTS: 100 studies were included describing 112 patients (26 prepubertal children and 86 adolescents). Differences were found between prepubertal children and adolescents regarding sex distribution (female-to-male ratio: 1:2 vs. 4:1), clinical manifestations, and concomitant clinical manifestations. LIMITATIONS: There was variation in the methods used to diagnose porphyria attacks across studies, and some elements of the quality of individual studies were unclear. CONCLUSIONS: Prepubertal children with AHPs and porphyria attacks presented with distinct demographic and clinical characteristics from adolescents and adults. Nearly two-thirds of the affected children were males, and about half had a concomitant medical condition that can constitutively upregulate hepatic δ-aminolevulinic acid synthase-1. Adolescents were comparable to adults in almost all respects.