Adhesion molecules are considered to have an important role in inflammatory reactions. We investigated the kinetics of ICAM‐1 expression on keratinocytes and correlated this with the numbers of lymphocytes expressing LFA‐1 in the dermis and epidermis of evolving allergic contact dermatitis reactions. In nickel‐sensitive individuals, after application of a nickel patch, increased expression of ICAM‐1 on keratinocytes was observed as early as 3 h and reached a maximum at 48 h. The number of lymphocytes expressing LFA‐1 in the dermis and epidermis was greatest at 48 h. The LFA cells were observed to be in close proximity to keratinocytes expressing ICAM‐1, thus supporting the hypothesis that T‐lymphocytes attach to keratinocytes via LFA‐1/ICAM‐1 molecules.