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The use of ultra-thin films as dressings for cutaneous wounds could prove advantageous in terms of better conformity to wound topography and improved vapour transmission. For this purpose, ultra-thin poly(epsilon-caprolactone) (PCL) films of 5-15 microm thickness were fabricated via a biaxial stretching technique. To evaluate their in vivo biocompatibility and feasibility as an external wound dressing, PCL films were applied over full and partial-thickness wounds in rat and pig models. Different groups of PCL films were used: untreated, NaOH-treated, untreated with fibrin, NaOH-treated with perforations, and NaOH-treated with fibrin and S-nitrosoglutathione. Wounds with no external dressings were used as controls. Wound contraction rate, histology and biomechanical analyses were carried out. Wounds re-epithelialized completely at a comparable rate. Formation of a neo-dermal layer and re-epithelialization were observed in all the wounds. A lower level of fibrosis was observed when PCL films were used, compared to the control wounds. Ultimate tensile strength of the regenerated tissue in rats reached 50-60% of that in native rat skin. Results indicated that biaxially-stretched PCL films did not induce inflammatory reactions when used in vivo as a wound dressing and supported the normal wound healing process in full and partial-thickness wounds.

The primary objective of this study was to assess the skin stripping of wounds (defined as periwound skin blistering; Fowler, 1990) when treated with an adhesive hydrocellular foam dressing (Allevyn trade mark Adhesive, Smith and Nephew) and a self-adherent soft silicone foam dressing (Mepilex trade mark Border, MöInlycke Health Care). The secondary objectives were to assess wound healing, wound appearance and pain. Data were collected over one year from 403 wounds in 206 patients treated in nursing homes. At follow-up assessment, there was some evidence of skin stripping with both products - 5% (5/106) with the adhesive hydrocellular, and 4% (4/100 with the self-adherent dressing. The results of the study reveal that the closure rates achieved with the two dressings were similar, and that both dressings were equally safe in terms of skin stripping. Independent nurse evaluations highlighted the failure of the self-adherent soft silicone foam dressing to either initially adhere to the wound area, or to remain in contact for more than a few days, and frequently needed the application of additional tape to ensure adhesion. The failure of the self-adhesive soft silicone foam dressing to adhere to the periwound area was a significant deterrent to staff to use this type of dressing routinely.

Staphylococcal scalded skin syndrome (SSSS) may cause significant morbidity in children. It is common practice for adhesive occlusive dressings to be used to apply topical local anaesthetic prior to venepuncture. We report two cases in which removal of these dressings from children with SSSS caused injury and discomfort in areas previously free from blistering. We recommend that an alternative method of topical anaesthetic application is used to minimize skin trauma in these patients.

Occlusion, widely used to enhance percutaneous absorption of drugs, also increases penetration of other chemicals and antigens, and hence may exacerbate irritant and allergic contact dermatitis. This overview summarizes the adverse effects of occlusion.

In order to investigate the effect of occlusion on the skin, the flexor sides of both upper arms were covered with column-shaped with column-shaped closed chambers, 30 mm in outer diameter, 20 mm in inner diameter, and 5 mm in height, which were made of polyethylene foam. The tops of the chambers were sealed by plastic films with various levels of water vapor permeability to control moisture in each chamber. The raised chamber walls prevented direct contact between the skin and the plastic film. After 24 h of application, morphological changes of the skin surface were observed microscopically by the nitrocellulose-replica method. Although no visual alterations were found on all areas of occluded skin, microscopic evaluation showed that simple occlusion by films induced an increase in the number of deepened skin furrows on the skin surface. this increase was associated with lower water vapor permeability of the films, as well as with higher values of both temperature and humidity of the test day. Thus, since conditions which facilitate perspiration from the skin tend to cause skin irritation, prolonged exposure of the skin to sweat by simple occlusion may act as a primary skin irritant.

It is common practice following mastoid and middle ear surgery to apply a pressure bandage to the ear for a short post-operative period to reduce local swelling. The bandage is usually secured in such a way as to lift it away from the eye, sometimes with a length of ribbon gauze tied in a knot over the temporal region. Pressure from the knot may cause injury to the underlying tissues leading to post-operative complications which hitherto have not been described.

Porcine full-thickness excisional wounds were treated with 4 different hydrocolloid (HCD) dressings--DuoDERM (ConvaTec/E. R. Squibb), Intrasite HCD (Smith and Nephew Medical), Tegasorb (3M) and Replicare (Smith and Nephew Medical). Animals were killed at 4, 10, 21 and 90 d post-wound, excision sites were fixed in formalin and processed for histological analysis. Granulomatous lesions were observed following treatment with each of the 4 HCD dressings. Such lesions developed between 4 and 10 d post-wound, exhibiting little evidence of resolution at 90 d post-wound. Of the 4 dressings examined, DuoDERM and Intrasite HCD precipitated the most severe reaction, each treatment resulting in granulomata with a distinct and different morphology. Treatment with DuoDERM resulted in granulomata characterised by a random distribution of dendritic cells, epithelioid cells, multinucleated giant cells, lymphocytes and plasma cells. In contrast, treatment with Intrasite HCD resulted in highly organised granulomata, consisting of a central focus of epithelioid cells surrounded by a peripheral cuff of macrophages, lymphocytes and plasma cells. This experimental study highlights chronic inflammatory lesions that may, if reflected in the clinical environment, question the efficacy and indication of HCD dressings in the treatment of wounds having a number of different aetiologies.

An occlusive dressing was applied to the unaffected skin of the back of a patient with familial benign chronic pemphigus (FBCP). Small lesions of FBCP appeared after 48 h, and the ultrastructure of successive biopsies was studied. It was concluded that: (a) the initial phenomenon in FBCP is the result of an insufficiency of cellular adhesion. This confirms several previous reports. (b) desmosomes are separated in two halves, invaginated in vacuoles and later deeply included in the cell. The particular fate of these disrupted desmosomes has already been observed after the action of several enzymes on the epidermis and in Darier's disease.

The effect of occlusion on the cutaneous microbial flora in patients with atopic dermatitis and psoriasis was measured. Significant increases in the density of Staphylococcus aureus and lipophilic diphtheroids were noted after occlusion in eczematous and psoriatic skins. While the incidence of S. aureus increased in psoriatic skin after occlusion, this trend was not noted in dermatitic skin.

Clinically normal skin was occluded for 3, 6, 24, and 48 hours with aluminium cups used for patch testing. Electron microscope sections from occluded skin showed morphological alterations in the Langerhans' cells and apposition of mononuclear cells. After occlusion an increased number of mononuclear cells were found in the epidermis, compared with normal skin.