Staphylococcus aureus has a peculiar ability to colonize the skin of patients with atopic dermatitis. We examined the possibility that this might be due to a specific ability of this pathogenic staphylococcus to adhere to atopic stratum corneum. We used an in vitro model to show that S aureus does have an unusual ability to adhere to atopic corneocytes when compared with corneocytes obtained from patients with other cutaneous diseases, including psoriasis. Protein A--a component of the staphylococcal cell wall--may be responsible in part for this adherence phenomenon. This trait did not extend to the other gram-positive bacteria tested.