The invention concerns a composition containing at least an oxazolin, optionally combined with at least a compound such as a metalloprotease inhibitor, a PKC inhibitor, an anti-inflammatory agent, a soothing agent, an immunosuppressor, an ion chelating agent, an alkanolamide, an oxazolidinone and a carbamic acid derivative. The invention also concerns the use of such a composition as medicine, in particular for preventing or treating skin pathologies of allergic and/or inflammatory and/or irritative origin or resulting from a danger signal. The invention further concerns a method for cosmetic treatment of sensitive, irritated, intolerant, allergy-prone, ageing skin and/or mucosa exhibiting skin barrier disorder, or exhibiting non-pathological immunologic imbalance, which consists in applying such composition on the skin and/or mucosa.