What? Allergic contact dermatitis (ACD) is a common inflammatory skin disease that affects approximately 15% of the adult European population. ACD develops when T cells are activated after exposure of the skin to a contact allergen. Due to the potential side effects of current treatments, sensitized individuals must take lifelong precautions to avoid re-exposure to allergens and prevent ACD flare-ups. Why? Not all develop ACD after exposure to contact allergens; instead, some develop tolerance towards the allergen through a currently unknown mechanism. However, recent research suggests that B cells may play a key role in inducing tolerance and preventing ACD. My research project will investigate the role of B cells in ACD and immune tolerance, potentially paving the way for improved ACD treatments. How? The project will be done at the Swizz Institute of Allergy and Asthma Research (SIAF), Switzerland. B cells will be isolated from blood taken from 20 p-phenylenediamine (PPD)-allergic patients and 20 PPD-tolerant individuals. The phenotype and function of the B cells will be assessed by cutting-edge techniques, including single-cell RNA sequencing, proximity extension assays and 3D-skin modeling.