The invention relates to a composition having antimicrobial and hygroscopic properties and the composition comprises a carboxylic acid compound as well as at least one C3-C6 diol and at least one C8-C12 diol. The composition of the invention may be used for cleansing, disinfection, surface treatment, impregnation and for antimicrobial treatment. The composition is particularly useful for treatment of fungal infections of the nail (onychomycosis).