UV transmission and UV protection factor (UPF) measured on split skin following exposure to UVB radiation — correlation with the minimal erythema dose (MED)

In this study the ultraviolet (UV) transmission of split skin exposed to UVB radiation and of non-exposed skin was compared in the 280-390 nm wavelength range and quantified. In addition, the correlation between the increase in the minimal erythema dose (MED) associated with a defined exposure to UVB and the ultraviolet protection factor (UPF) calculated from the transmission data was investigated. The study population consisted of 12 patients. Two pieces of split skin of the same thickness (0.3 mm) were taken from the right thigh of each patient. One specimen was removed from an area of non-exposed healthy skin and the other from an area which had been exposed to UVB radiation for a period of 12 days in which the initial dose of 1/3 MED was raised by 1/3 MED every 4 days. The split skin specimens were stretched over a special frame; subsequently, the UV transmission was determined with a spectrophotometer. The mean values obtained for UV transmission were all significantly below the initial data for non-exposed split skin. In the UV range of 280--390 nm, the transmission measured in the exposed specimens was 49.1% of the value measured in the non-exposed split skin (P<0.05). The corresponding values for the UVA range (315--390 nm) and the UVB range (280--315 nm) were 50.1% and 29.5%, respectively (P<0.05), based on the initial transmission data obtained from non-exposed skin. The clinical determination of MED after 12 days of exposure to UVB yielded mean values that were 3.2 times the initial values. Moreover, the mean UPFs calculated from the transmission data measured at the end of the 12-day exposure period were also about three times the initial values. The present study has thus established a significant correlation between the clinical MED values and the UPFs calculated from the transmission data measured following exposure to UVB.     

Immunohistologic characterization of stasis dermatitis transformed skin of the lower leg

Antibodies against human T-lymphocytes and their subpopulations were applied to frozen sections obtained from skin affected with stasis dermatitis of the lower leg from 13 patients suffering from chronic venous insufficiency. In all cases, we observed an intense staining reaction with HLA-DR antibodies, i.e. mainly monocytes, macrophages, fibroblasts, and endothelial cells. Control sections of clinically normal skin taken from patients without stasis dermatitis showed only staining of endothelial cells and of dendritic epidermal cells with HLA-DR antigens. The dermal infiltrate in stasis dermatitis displayed only moderate staining with antigens directed against T-helper and T-suppressor cells. Our findings of large quantities of HLA-DR positive cells in skin affected with stasis dermatitis points to their possible role with regard to the induction and persistence of contact allergies so frequently encountered in this group of patients.     

Effects of UV irradiation with one minimal erythema dose on human afferent skin lymph in vivo

Ultraviolet (UV) irradiation of the skin induces complex local and systemic immunomodulatory reactions. The biological effects of UV irradiation on human skin derived afferent lymph however are unknown. The aim of this study was to examine the effects of a single combined UV-A and UV-B irradiation with 1 minimal erythema dose (MED) on human skin derived lymph in vivo. After cannulation of a superficial lymph vessel on the lower leg, lymph flow and cell output per hour were determined before and for 6 days after UV irradiation of the lymph draining skin area in 5 volunteers. Furthermore, expression of CDla, CD4, CD8, CD28, CD54, CD80, CD86 and HLA-DR on migrating lymph cells and cytokine levels (IL-1α, IL-1β, IL-2, IL-6, IL-8, IL-10, IL-13, TNF-α and IFN-γ) in the afferent lymph were analyzed by cytofluorometry and ELISA. After UV irradiation a small initial enhancement in the daily lymph flow per hour was noticed in correlation with the slight erythematous skin reaction. Following resolution of the skin reaction, a delayed increase in cell output in correlation with an additional peak in the lymph flow was found between the 4th and 6th day after UV irradiation. However, no changes in the expression of CDla, CD4, CD8, CD28, CD54, CD80, CD86 and HLA-DR on migrating lymph cells were detectable. Interestingly, in parallel to the increased lymph flow and cell output, only elevated IL-8 protein levels were reproducibly detected in the afferent lymph after UV irradiation. Furthermore, using immunohistochemistry positive staining for IL-8 was found on migrating mononuclear lymph cells. In conclusion, our data demonstrate that a single UV irradiation of the skin with 1 minimal erythema dose leads to a delayed enhancement of lymph flow, number of migrating lymph cells and cytokine levels of IL-8. Moreover, we provide evidence that migrating lymph cells, besides resident epidermal and dermal cells, may contribute to the detected levels of IL-8 in the afferent lymph.     

Comparison of inpatient bed rest and home convalescence following split thickness skin grafting to the lower leg

There has been a substantial move towards care of patients in an outpatient setting. This study was performed to determine if discharge home following split thickness skin grafting to the lower leg compromised graft results or morbidity compared with admission to hospital. Cases were reviewed retrospectively from the dermatology department's surgical records. All split thickness skin grafts to the lower legs over a 12-month period were included. All clinical notes were reviewed and phone calls made to patients and relatives. A total of 61 cases were included: 31 admitted as inpatients, 30 discharged home. There was no significant difference between the two groups' age, sex or comorbidities. A trend was seen in inpatients towards increased infection (P = 0.19) and venous thrombosis (P = 0.34). There is a lack of significant difference between admitted and discharged patients in all outcomes including bleeding, number of dressing clinic follow ups and graft loss. These results suggest that home convalescence after split thickness skin grafting to the lower legs compares favourably with inpatient care.     

Primary and secondary skin cancers affecting the lower extremity: Tumorous leg ulcers

Skin cancer can be primary or de novo, as in the commonest of cases, those due to chronic sun exposure. Alternatively, secondary malignancies less frequently can he associated directly with benign dermatoses. These secondary cancers may be internal, as in hepatoma developing in patients with porphyria cutanea tarda, or external, as in the association of epidermodysplasia verruciformis with squamous cell carcinoma of the skin. Some of these primary and secondary neoplasms may also affect or have a tendency to involve certain regions of the body such as the lower extremity. De novo skin cancers affecting the lower extremity include: Kaposi's sarcoma, malignant melanoma, lymphoma and metastases. Secondary cutaneous malignancies that affect the legs and feet are mostly within the category of chronic ulcerative and scarifying conditions such as burn scars, frostbite, osteomyelitis, radiation dermatitis, stasis, infections, trauma, aerodermatitis chronica atrophicans, epidermolysis bullosa. and lichen planus. Other dermatoses directly related to skin cancer development on the lower limb include the KID syndrome, porokeratosis, tylosis, verrucous carcinoma, and lymphedema.     

Mechanisms of reactive oxygen species-induced skin erythema and superoxide dismutase activities in guinea pigs

Reactive oxygen species (ROS)-induced skin erythema was produced by injection of xanthine oxidase (XOD) and hypoxanthine (HPX), an ROS-producing system, into guinea pig skin. The clinical course of the erythema was examined in relationship to the age of the animal as well as to superoxide dismutase (SOD) activity of the skin. The ROS-induced skin erythema reached a peak 24 hr after injection of XOD and HPX macroscopically and histologically with the reduction of skin SOD activity, and the severity of erythema was age-dependent. The increased severity of the skin erythema with age was related to the reduction of the skin SOD activities after XOD plus HPX injection. This skin erythema will provide a good model for the investigation of oxidative tissue injuries observed in several skin disorders.     

Onychomycosis in patients with chronic leg ulcer and toenail abnormalities

Nails have a limited number of reactive patterns to disease. Accordingly, toenail changes of different etiologies may mimic onychomycosis.

OBJECTIVE

To determine the prevalence of toenail onychomycosis among patients with leg ulcer and toenail abnormalities attending a dermatology clinic.

METHODS

A cross-sectional study was conducted through the analysis of clinical records and results of mycological examination.

RESULTS

A total of 81 patients were included, with a median age of 76.0 years. Most ulcers were of venous etiology, followed by those of mixed and arterial pathogenesis. The mycological evaluation confirmed the diagnosis of onychomycosis in 27.2% of the patients. The etiologic agent was a dermatophyte in 59.1% of isolates in nail samples, while Trichophyton interdigitale was the most frequent fungal species (40.9%).

CONCLUSIONS

Most toenail abnormalities in patients with chronic leg ulcer were not onychomycosis. This study highlights the importance of systematic mycological examination in these patients, in order to avoid overtreatment with systemic antifungals, unnecessary costs and side effects.     

The self-recovery of facial skin barrier and erythema after nanochip treatment

Objective: To determine the degree of acute skin damage and the time required for the recovery of facial skin barrier function after the skin was treated with micro-needles and nanochips of various tip lengths. Methods: For this split face comparative study, a total of 16 subjects were enrolled and randomly divided into 2 groups. In the first group, one of the facial side of each subject was treated with 0.25-mm long nanotips for a total of 6 times while the other facial side was treated with 0.25-mm traditional micro-needles with a straight blade for a total of 6 times. In the second group, one of the facial side was treated with 0.5-mm nanotips for a total of 6 times while the other facial side was treated with 0.5-mm traditional micro-needles with a straight blade for a total of 6 times. Evaluations for trans-epidermal water loss (TEWL), skin hydration and erythema were carried out at baseline, 0, 4, 8, 24, 48 and 72 hours after the treatment. Results: There was no significant difference in TEWL, skin hydration and erythema between the two facial sides of the subjects in the Group one who were treated with 0.25 mm nanochips and traditional micro-needles. However, in the subjects of the Group two, the mean TEWL of the facial side treated with 0.5 mm nanochips was relatively lower than that of the 0.5 mm traditional micro-needles treated facial side at 0, 4, 8 and 24 hours after the treatment. Mean erythema of the facial side treated with 0.5-mm nanochips micro-needles was also relatively lower than that of the 0.5-mm traditional micro-needles treated facial side at 8 hours after the treatment. Rapid recovery of skin barrier function was observed within 4–8 hours after treatment with various lengths of nanochips while it took at least 48–72 hours for recovery of skin barrier function after treatment with various lengths of traditional micro-needles as measured by TEWL. Conclusion: The skin disruption caused by nanotips treatment recovers quicker than the traditional microneedle treatment at equal lengths.