Contact dermatitis in hospital patients.

Contact dermatitis in hospital patients resulting from diagnostic and therapeutic procedures presents various causes and clinical aspects. Antiseptics are the most frequent cause of contact dermatitis in patients undergoing surgery. Thimerosal may cause allergic sensitization mainly in patients previously exposed to contact with different sources of these mercurials, such as tinctures and preservatives in other products. Iodine-containing solutions and quaternary ammonium compounds rarely sensitize. They may cause irritation under certain circumstances, however. Adhesive tapes formulated on a rubber and colophony base are rarely found nowadays in medical adhesives; however, some tapes and skin closures have still been found to contain them. Acrylate-based adhesives sensitize less frequently. Cardiology patients may present contact dermatitis from several different sources. Electrode gels and pastes may cause allergic contact dermatitis mainly from preservatives. Modern electrocardiographic equipment does not require the use of these products, so many of these problems are now easy to avoid. Adhesive-coated pregelled foam disks for holding long-term chest contacts may cause irritant dermatitis. Transdermal drug delivery systems such as nitroglycerin disks may cause irritation attributable to the acrylic adhesives. Silicone-based adhesive disks are a good alternative in this case. Sensitization to nitroglycerin itself is rare. Dermatitis originated from implantation of pacemakers is attributable either to epoxy resin or to the metal used for the casing of the pacemaker. Changing to a different material solves the problem. In other instances, the etiology remains unclear. Dermatoses in patients with stomas constitute an important problem not only because of their frequency but also because of the multiplicity of pictures involved. Irritant dermatitis from intestinal efflux in ileostomy patients is the most frequent problem. Allergic dermatitis may originate from the ostomy device, cementing materials, or topical medicaments. Individuals receiving hemodialysis have been reported to develop widespread dermatitis, probably secondary to rubber or metal components leached out from the hemodialysis apparatus. Systemic exposure to these compounds, although not certainly proved, seems to be the explanation. Allergic dermatitis at the puncture site on arteriovenous shunts has been demonstrated to be produced by epoxy resin adhesives present in catheters. Identification of the allergen allows one to find a safe alternative for these patients who depend on this procedure to survive. Contact dermatitis in hospital patients requires a precise diagnosis. Extensive patch testing is sometimes needed for establishing the cause, which in turn provides a more accurate prognosis and a rational treatment.