Lactylation, as an emerging post-translational modification mediated by lactate, has recently been identified as a critical regulator of immunometabolic reprogramming and inflammatory responses in allergic diseases. This review synthesizes current evidence on the role of lactylation in modulating immune cell dynamics, including macrophage polarization, dendritic cell antigen presentation, t-cell differentiation, and mast cell activation. We highlight how lactate accumulation in allergic microenvironments drives epigenetic modifications, such as histone lactylation, to influence immune cell function and metabolic adaptation. Key findings demonstrate that lactylation serves as a bidirectional regulator, promoting either pro-inflammatory or anti-inflammatory responses depending on cellular context and lactate concentrations. Despite the research progress, challenges remain in understanding the transient nature of lactylation and tissue-specific dynamics. Future research could integrate spatial omics and advanced imaging technologies to unravel lactylation's spatiotemporal regulation, offering novel therapeutic strategies for allergic disorders.