The invention relates to a dermatological or pharmaceutical composition comprising at least one aqueous phase and at least one active phase comprising at least one active compound chosen from avermectin compounds and at least one solvent and/or propenetrating agent of avermectin compounds, where the composition comprises less than 3% by weight of solid fatty substances at room temperature and at atmospheric pressure, relative to the total weight of the composition.The invention relates also to the composition for use in the treatment of rosacea, of common acne, of seborrheic dermatitis, of perioral dermatitis, of acneiform rashes, of transient acantholytic dermatosis, of acne necrotica miliaris and of atopic dermatitis, and preferably for use in the treatment of rosacea.Finally, the invention relates to a method for preparing the composition.