Most tonsillectomies in the UK are performed to treat acute recurrent tonsillitis (ART) and tonsil hypertrophy due to obstructive sleep apnoea (OSA). At present, the pathophysiology of these 2 common conditions is still poorly understood. We have performed optical mesoscopic imaging to reveal the spatial location of two interleukins, IL-17C and IL-1 Beta, associated with tonsillar conditions, with the aim of understanding their possible role as specific disease biomarkers. Using immunofluorescence assays, we have shown that the expression of IL-17C is significantly higher in both the epithelial tissue (p < 0.0001) and core tissues (p = 0.0007) of specimens from patients with ART compared to patients with OSA (n = 17 patients). We also demonstrated significantly higher expression of IL-17C in homogenates of ART patient tissue compared to OSA tissue (p = 0.05). These data show the promise of IL-17C as a biomarker for ART and we propose this as a possible new approach to discriminate ART from OSA.