The present invention relates to an antibacterial composition, preferably for topical use, comprising triethyl citrate and a peptide consisting of 15 amino acids of sequence FAKALKALLKALKAL-NH2, wherein F is phenylalanine, A is alanine, K is lysine and L is leucine, particularly for the treatment of acne, suppurative or non-suppurative hidradenitis, atopic dermatitis characterized by colonization by