Legionella infection is rare in children, and extrapulmonary manifestations are even less commonly reported. Cutaneous involvement, particularly in the form of generalized pustular eruptions, may present significant diagnostic and therapeutic challenges, especially in immunocompromised patients. We report a male infant under 6 months with X-linked severe combined immunodeficiency (XL-SCID) who presented with a disseminated pustular rash as the predominant clinical feature. Initial blood and pus cultures were negative, and empirical antimicrobial therapy showed limited clinical response. Metagenomic next-generation sequencing (mNGS) was subsequently performed and identified Legionella as the causative pathogen. Based on this finding, the antimicrobial regimen was adjusted to include a macrolide antibiotic combined with trimethoprim-sulfamethoxazole (TMP-SMX), resulting in significant clinical improvement and eventual recovery. This case highlights the atypical presentation of Legionella infection with predominant cutaneous manifestations in children, particularly in the context of primary immunodeficiency, and underscores the diagnostic value of mNGS in cases with inconclusive conventional testing. Early application of advanced molecular diagnostics and timely optimization of targeted antimicrobial therapy are crucial for improving outcomes in rare and complex pediatric infections.
Zeng et al. (Wed,) studied this question.