A skin model comprises keratinocytes capable of overexpressing filaggrin. A method for evaluating the in vitro activity of a formulation or of at least one active agent on the healing of nipple skin and/or on the reduction of nipple skin inflammation, by bringing said active agent or said formulation into contact with a skin model comprising keratinocytes overexpressing filaggrin and also comprising a lesion, and measuring the level of production of at least one biological marker chosen from lactate dehydrogenase (LDH), TNFα, filaggrin, TGFβ1 and β1 integrin.