BCG Scar Reactivation (BCGitis) in Kawasaki Disease: A Scoping Literature Review

Bacillus Calmette-Guérin (BCG) scar reactivation (BCGitis) is a distinctive clinical sign reported in Kawasaki disease (KD), yet evidence remains scarce across the literature. We aimed to summarize the epidemiology, chronology, clinical correlates, and coronary outcomes associated with BCGitis in KD.

We conducted a PRISMA-ScR-guided scoping review of studies describing BCGitis in KD. Data were synthesized descriptively across retrospective cohorts and case reports/series.

Forty studies published between 1997 and 2024 were included (10 retrospective cohorts; 30 reports of 36 cases). BCGitis was most frequently described in infants and young children (< 2 years, often < 6-12 months) and was commonly associated with earlier recognition and treatment. Reported BCGitis prevalence varied across cohorts, from 11.8% to 49.9%. Coronary artery lesions (CAL) and IVIG resistance were reported at lower rates in some cohorts; however, these findings were not statistically significant. In the case reports, most patients were infants, male predominance was observed, and incomplete KD was frequent. BCGitis was often reported during the early febrile phase, sometimes preceding complete KD diagnostic criteria. Most reported cases responded to IVIG. Coronary abnormalities were usually mild or transient, although two giant aneurysms, one case of Kawasaki disease shock syndrome, and one mortality were reported.

BCGitis may support earlier recognition of KD, particularly in incomplete presentations, potentially facilitating timely recognition and treatment. Incorporation of BCGitis into diagnostic algorithms may improve patient outcomes. Future studies should standardize reporting of BCGitis chronology, coronary outcomes, and evaluate the incremental diagnostic value of BCGitis in prospective cohorts.