ABSTRACT
LOCAL OR MECHANICAL Skin Considering the risk factors for the development of infections in the immunocompromised host, such as the cancer patient, especially during treatment, the skin barrier integrity represents a major contributor of host defense [2]. When intact, this mechanical barrier is one of the first lines of defense against the invasion of microorganisms. Very few microorganisms have the ability to penetrate the skin on their own; they require other means to overcome this barrier. In the case of a cancer patient, these means may include an intravenous catheter, a surgical incision, a disruption of the skin by trauma, or also for the general population an arthropod vector sting. The skin has unfriendly conditions for pathogens, such as dryness and desiccating properties and mild acidic pH of 5 to 6. The normal skin flora also antagonize the proliferation of other pathogenic bacteria. The action of indigenous flora on skin secretions such as sebum creates a hostile acidic environment for bacteria. From a mechanical point of view, normal exfoliation of skin scales promotes the simultaneous shedding of microorganisms. Skin inflammation is associated with augmentation of water permeability and easier colonization by microorganisms. The number of skin-penetrating indwelling arterial and venous catheters has been described as a factor facilitating pathogen invasion in the immunocompromised host [2]. Hemorrhagic diathesis with resulting hematomas in association with mechanical skin disruption such as that due to needle sticks is also a factor that promotes increased skin permeability and pathogen invasion [2]. Thorough evaluation and careful examination of the skin is a very important part of the care of the cancer patient. Skin integrity disruption by rashes, petechiae, ecchymosis, hematomas, ecthyma, or catheter insertion sites can result in local and systemic infection. This clinical information is important in decision making regarding the choice of antibiotics, dosages, or the need to change treatment [3]. The importance of skin barrier integrity protection is well known to those caring for cancer patients with infections. On the other hand, the skin can also be a temporary carrier for pathogens. Currently, the mainstay in the prevention of patient cross contamination is thorough hand washing after examining patients and in between
procedures [4). Graft-versus-host disease (GVHD) in the allogeneic bone marrow, stem cell, or cord blood transplantation along with its immunocompromising effects changes the skin structure dramatically and may contribute to an increase risk of infection.
