Search PubMed⌕ Search

Biomedical subjects

H C Wulf

Publications and source records attributed to H C Wulf.

At least 19 recordsLinked to original sources
PubMed2006

Carcinogenesis related to intense pulsed light and UV exposure: an experimental animal study.

This study examines whether intense pulsed light (IPL) treatment has a carcinogenic potential itself or may influence ultraviolet (UV)-induced carcinogenesis. Secondly, it evaluates whether UV exposure may influence IPL-induced side effects. Hairless, lightly pigmented mice (n=144) received three IPL treatments at 2-week intervals. Simulated solar radiation was administered preoperatively [six standard erythema doses (SED) four times weekly for 11 weeks] as well as pre- and postoperatively (six SED four times weekly up to 26 weeks). Skin tumors were assessed weekly during a 12-month observation period. Side effects were evaluated clinically. No tumors appeared in untreated control mice or in just IPL-treated mice. Skin tumors developed in UV-exposed mice independently of IPL treatments. The time it took for 50% of the mice to first develop skin tumor ranged from 47 to 49 weeks in preoperative UV-exposed mice (p=0.94) and from 22 to 23 weeks in pre- and postoperative UV-exposed mice (p=0.11). IPL rejuvenation of lightly pigmented skin did not induce pigmentary changes (p=1.00). IPL rejuvenation of UV-pigmented skin resulted in an immediate increased skin pigmentation and a subsequent short-term reduced skin pigmentation (p<0.002). Postoperative UV radiation resulted in re-pigmentation of IPL-induced pigment reduction (p=0.12). No texture changes were observed. Postoperative edema and erythema were increased by preoperative UV exposure (p<0.002). IPL rejuvenation has no carcinogenic potential itself and does not influence UV-induced carcinogenesis. UV exposure influences the occurrence of side effects after IPL rejuvenation in an animal model.

Animals↗
PubMed2006

Ultraviolet radiation exposure pattern in winter compared with summer based on time-stamped personal dosimeter readings.

BACKGROUND: Personal annual ultraviolet (UV) radiation data based on daily records are needed to develop protective strategies. OBJECTIVES: To compare UV radiation exposure patterns in the winter half-year (October-March) and the summer half-year (April-September) for Danish indoor workers. METHODS: Nineteen indoor workers (age range 17-56 years) wore personal UV dosimeters, measuring time-stamped UV doses continuously during a year. The corresponding sun exposure behaviour was recorded in diaries. Similar data were collected for 28 volunteers during sun holidays in the winter half-year. The relationship between UV dose and sun exposure behaviour was analysed. RESULTS: The ambient UV dose during the winter in Denmark (at 56 degrees N) was 394 standard erythema doses (SED) or 10.5% of the annual ambient UV dose. In winter compared with summer the subjects had: (i) a lower percentage of ambient UV radiation, 0.82% vs. 3.4%; (ii) a lower solar UV dose in Denmark, 3.1 SED (range 0.2-52) vs. 133 SED (range 69-363); (iii) less time outdoors per day with positive dosimeter measurements, 10 min vs. 2 h; and (iv) no exposure (0 SED) per day on 77% vs. 19% of the days. Sun holidays outside Denmark in winter gave a median 4.3 SED per day (range 0.6-7.6) and 26 SED (range 3-71) per trip. CONCLUSIONS: In the winter half-year indoor workers received a negligible UV dose from solar exposure in Denmark and needed no UV precautions. No UV precautions are needed from November to February during holidays to latitudes above 45 degrees N, while precautions are needed the whole year around at lower latitudes.

Adolescent↗
PubMed2006

Life quality assessment among patients with atopic eczema.

BACKGROUND: Quantification of quality of life (QoL) related to disease severity is important in patients with atopic eczema (AE), because the assessment provides additional information to the traditional objective clinical scoring systems. OBJECTIVES: To measure health-related QoL (HRQoL) in patients with AE; to analyse discriminant, divergent and convergent validity by examining the association between various QoL methods; and to examine the association between disease severity assessed by an objective Severity Scoring of Atopic Dermatitis (SCORAD) and QoL. METHODS: HRQoL was assessed at two visits at a 6-monthly interval in 101 patients with AE and 30 controls with one dermatology-specific questionnaire [Dermatology Life Quality Index (DLQI) or Children's DLQI (CDLQI)], one generic instrument (SF-36) and three visual analogue scales (VASs) of severity and pruritus. Objective SCORAD was used to measure disease severity. RESULTS: Patients with AE had significantly lower QoL than healthy controls and the general population. DLQI /CDLQI, pruritus, and patient and investigator overall assessment of eczema severity were significantly (P < 0.0001) and positively correlated with SCORAD, while the generic questionnaire showed only poor correlation. A gender difference was found for the mental component score of SF-36 (P = 0.019). CONCLUSIONS: AE has an impact on HRQoL. Patients' mental health, social functioning and role emotional functioning seem to be more affected than physical functioning. A simple VAS score of patients' assessment of disease severity showed the highest and most significant correlations with most of the HRQoL methods used. There is evidence to support the ability of patients with AE to make an accurate determination of their disease severity and QoL.

Adolescent↗
PubMed2006

Photodynamic therapy of acne vulgaris using methyl aminolaevulinate: a blinded, randomized, controlled trial.

BACKGROUND: Inflammatory acne vulgaris is a very common condition, particularly in adolescents and young adults, and new effective and well-tolerated treatments are needed. OBJECTIVES: To evaluate the efficacy and tolerability of methyl aminolaevulinate-based photodynamic therapy (MAL-PDT) in patients with moderate to severe facial acne vulgaris in a randomized, controlled and investigator-blinded trial. METHODS: Twenty-one patients were assigned to the treatment group and 15 patients to the control group. The treatment group received two MAL-PDT treatments, 2 weeks apart. Both groups were evaluated 4, 8 and 12 weeks after treatment. Efficacy evaluation included changes from baseline in numbers of noninflammatory and inflammatory lesions, changes from baseline in global acne severity grade and clinical assessments of clinical improvement by patient and evaluating dermatologist. Pain scores during treatment and local adverse effects were also evaluated. RESULTS: Twelve weeks after treatment the treatment group showed a 68% reduction from baseline in inflammatory lesions vs. no change in the control group (P=0.0023). We found no reduction in number of noninflammatory lesions after treatment. All patients experienced moderate to severe pain during treatment and developed severe erythema, pustular eruptions and epithelial exfoliation. Seven patients did not receive the second treatment due to adverse effects. CONCLUSIONS: MAL-PDT proved to be an efficient treatment for inflammatory acne. The treatment was associated with severe pain during treatment and severe adverse effects after treatments. Efforts must be made to optimize the treatment regimen and to avoid adverse effects.

Acne Vulgaris↗
PubMed2006

Evidence-based review of hair removal using lasers and light sources.

BACKGROUND: Unwanted hair growth remains a therapeutic challenge and there is a considerable need for an effective and safe treatment modality. OBJECTIVE: From an evidence-based view to summarize efficacy and adverse effects from hair removal with ruby, alexandrite, diode, and Nd:YAG lasers and intense pulsed light (IPL). METHODS: Original publications of controlled clinical trials were identified in Medline and the Cochrane Library. RESULTS: A total of 9 randomized controlled (RCTs) and 21 controlled trials (CTs) were identified. The best available evidence was found for the alexandrite (three RCTs, eight CTs) and diode (three RCTs, four CTs) lasers, followed by the ruby (two RCTs, six CTs) and Nd:YAG (two RCTs, four CTs) lasers, whereas limited evidence was available for IPL sources (one RCT, one CT). Based on the present best available evidence we conclude that (i) epilation with lasers and light sources induces a partial short-term hair reduction up to 6 months postoperatively, (ii) efficacy is improved when repeated treatments are given, (iii) efficacy is superior to conventional treatments (shaving, wax epilation, electrolysis), (iv) evidence exists for a partial long-term hair removal efficacy beyond 6 months postoperatively after repetitive treatments with alexandrite and diode lasers and probably after treatment with ruby and Nd:YAG lasers, whereas evidence is lacking for long-term hair removal after IPL treatment, (v) today there is no evidence for a complete and persistent hair removal efficacy, (vi) the occurrence of postoperative side-effects is reported low for all the laser systems. CONCLUSION: The evidence from controlled clinical trials favours the use of lasers and light sources for removal of unwanted hair. We recommend that patients are pre-operatively informed of the expected treatment outcome.

Controlled Clinical Trials as Topic↗
PubMed2005

Ultraviolet exposure patterns of Irish and Danish gardeners during work and leisure.

BACKGROUND: Skin cancer, caused by solar ultraviolet (UV) radiation, is a growing problem in Europe. Reliable data on occupational exposure of outdoor workers are needed to develop protective strategies. OBJECTIVES: To compare UV radiation exposure patterns between outdoor workers in two European populations. METHODS: Fifty-three gardeners, 31 Irish and 22 Danish (age range 24-69 years) wore personal UV dosimeters, measuring time-stamped UV doses continuously during a 4-month summer period. The current and historical sun exposure pattern was recorded by means of a diary and questionnaire. Assessment of pigmentation, naevi, freckles and solar lentigines was performed. The relationship between UV dose and sun exposure pattern was analysed. RESULTS: Regarding work days, the Irish had a significantly lower percentage of ambient UV exposure than the Danes, 4.5% vs. 8.1%; a lower UV dose per day, 0.97 standard erythema dose (SED) vs. 1.6 SED; a lower UV dose between 12.00 and 15.00 h, 0.43 SED vs. 0.75 SED; and fewer hours with positive dosimeter measurements, 3.2 h vs. 4.8 h (all values are medians, P < 0.01). Regarding days off work, the same patterns emerged for both UV doses and exposure hours. The Irish had significantly fewer days off than the Danes, median 21 days vs. 49 days, and fewer days with risk behaviour (sunbathing/exposing upper body), median 0 days vs. 8 days (P < 0.01). CONCLUSIONS: The lower UV exposure received by the Irish gardeners may have been due to indoor breaks during peak ambient UV. Other contributing factors may include differences in natural shade between the parks. Our data suggest that consideration of such factors in scheduling of outdoor work can significantly reduce the occupational UV exposure.

Adult↗
PubMed2004

Allergic contact dermatitis to 5-aminolaevulinic acid methylester but not to 5-aminolaevulinic acid after photodynamic therapy.

We report a patient with an allergy induced by photodynamic therapy (PDT) following simultaneous treatment with both 5-aminolaevulinic acid (ALA) and ALA methylester (ALA-ME). After several PDT treatments the patient presented with acute eczema of the treated areas and itch and hyper-reactivity of the untreated skin. Patch testing demonstrated a strong +++ reaction to ALA-ME only, indicating that derivatives common to ALA and ALA-ME were not involved. This is the first case of allergy to ALA-ME.

Adult↗
PubMed2004

Skin autofluorescence as a biological UVR dosimeter.

BACKGROUND/PURPOSE: Collagen is one of the major endogenous skin fluorophores. Alteration in the structure of collagen due to chronic ultraviolet radiation (UVR) exposure may influence the intensity of the autofluorescence. The aim of this study was to investigate the relation between collagen-linked autofluorescence and sun exposure to clarify whether the skin can be used as a biological UVR dosimeter. METHODS: We conducted an in vivo study with 131 healthy volunteers. Fluorescence was measured from sun-exposed (dorsal forearm, forehead and shoulder) and sun-protected (buttock) skin and corrected for the impact of pigmentation and redness. The excitation wavelengths (Ex) and emission wavelengths (Em) were: Ex330:Em370, Ex330:Em455 and Ex370:Em455 nm. Individual UVR exposure data were collected both retrospectively and prospectively using questionnaires and electronic personal UVR dosimeters for a summer period. RESULTS: Age, but not sex, skin type or smoking habits correlated significantly positively with skin autofluorescence at Ex370:Em455 at all body sites (P<0.001, r(2)=0.08-0.26), and at Ex330:Em455 only at the buttock (P=0.001, r(2)=0.08), whereas age was not correlated with Ex330:Em370. Sun-protected buttock skin had significantly higher autofluorescence than sun-exposed skin (P-values<0.0001). Because of great between-subject differences in autofluorescence at different body sites, and because the autofluorescence at the unexposed buttock represents the baseline value, individual correction of skin autofluorescence measurement with that of the buttock was performed. Different measures of individual chronic cumulative UVR doses correlated significantly negatively with the skin autofluorescence ratio (F(ratio)), but the correlations were poor (r(2)=0.03-0.10). CONCLUSION: The results indicate that the collagen-linked skin F(ratio) might be best to use as a measure of individual photodamage, a UVR dose effect, and that it is also a better marker of individual cumulative UVR dose than the used UVR exposure measurements. The methods used to obtain UVR exposure data might not be sensitive and specific enough.

Adolescent↗
PubMed2004

Minimal erythema dose after multiple UV exposures depends on pre-exposure skin pigmentation.

BACKGROUND/PURPOSE: Phototherapy consists of multiple ultraviolet (UV) exposures. Most previous studies have focused on erythema following a single UV exposure in fair-skinned persons. Although it is well known that phototherapy lowers the daily UV-threshold dose for erythema in clinical practice, this is insufficiently documented under controlled experimental conditions. The purpose of this study was to quantify the change in the daily threshold for a dose specific erythema grade after 1-4 consecutive daily UV exposures. METHODS: Forty-nine healthy volunteers (skin type II-V) with varying pigmentation quantified by skin reflectance. Two UV sources were used: a narrowband UVB (Philips TL01) and a Solar Simulator (Solar Light Co.). Just perceptible erythema after 24 h was chosen as the minimal erythema dose (+); besides + and ++ were assessed. RESULTS: We found a positive and significant exponential relationship between skin pigmentation and UV dose to elicit a specific erythema grade on the back after 1-4 UV exposures. After repetitive UV exposures the UV dose had to be lowered more in dark-skinned persons compared with fair-skinned persons to elicit a certain erythema grade. This applied to both UV sources and all erythema grades. CONCLUSION: In the dark-skinned persons the daily UV dose after the 4 days UV exposure should be lowered by 40-50% to avoid burns compared with the single UV exposure. For the most fair-skinned persons essentially no reduction in the daily UV dose was needed. Our results indicate that the pre-exposure pigmentation level can guide the UV dosage in phototherapy.

Adult↗
PubMed2004

Durability of the sun protection factor provided by dihydroxyacetone.

BACKGROUND/PURPOSE: The sunless tanning agent dihydroxyacetone (DHA) is known to protect against longwave ultraviolet radiation (UVA) and visible light. Recently, our laboratory has shown that DHA in addition offers a modest sun protection factor (SPF) in humans. We conducted this study in order to investigate the durability of the SPF provided by DHA. METHODS: Ten healthy volunteers were treated with 20% DHA cream twice in three areas on the volar forearm. One, 5 and 7 days after the second application the participants were phototested with simulated sunlight in each area. Blue reflectance was used to measure the skin coloration by DHA in the test sites. RESULTS: DHA generated a significant SPF of 3.0 at day 1, 2.0 at day 5 and 1.7 at day 7 (P<0.0001). The SPF was positively correlated to the change in blue reflectance (r=0.39, P=0.034). The loss of SPF unit/day was not significantly different between the subjects (P<0.122). However, the intercepts were significantly different (P<0.0001) indicating differences in the initial SPF obtained among the subjects. CONCLUSIONS: The SPF of DHA decreases with the same loss of SPF unit/day between humans and the durability of the SPF thus depends on the initial SPF provided.

Administration, Cutaneous↗
PubMed2003

Emollients and the response of facial skin to a cold environment.

BACKGROUND: It is debated whether the use of emollients, in cold weather, constitutes a protective factor or a risk factor for frostbite. OBJECTIVES: To compare the effects of two emollients [oil in water (O/W) and petrolatum] on facial skin in response to cold exposure. METHODS: Fifteen volunteers participated in the experiment, consisting of 60 min in a cold room (-5 degrees C), preceded and followed by 30 min of acclimatization at room temperature. In the cold room, O/W was applied on one cheek and petrolatum on the other. The cheeks were exposed to wind, produced by a fan, to cool further the skin by the wind chill index. Skin temperature, redness, and transepidermal water loss (TEWL) were measured on both cheeks. RESULTS: Facial skin treated with O/W was significantly colder (up to 1.3 degrees C) than facial skin treated with petrolatum, but the difference disappeared within 20 min. Agreement between temperature measurements and subjective thermal sensations was poor (Cohen's kappa = -0.13). At no point did the paired skin redness and the paired TEWL values vary significantly. The TEWL levels were significantly lower 30 min after the cold exposure than before, but had reached pre-exposure levels the following day. CONCLUSIONS: This study demonstrates that for a duration exposure of 20 min, facial skin treated with O/W achieves a lower temperature than facial skin treated with petrolatum. The two emollients had in all other aspects the same effect on the response of facial skin to cold.

Adult↗
PubMed2003

Topical methyl aminolaevulinate photodynamic therapy in patients with basal cell carcinoma prone to complications and poor cosmetic outcome with conventional treatment.

BACKGROUND: Conventional treatment of basal cell carcinoma (BCC) causes morbidity and/or disfigurement in some patients because of the location (e.g. mid-face) and size of the lesion. OBJECTIVES: Following reports that such difficult-to-treat BCC lesions have been treated successfully with topical methyl aminolaevulinate (MAL) photodynamic therapy (PDT), a multicentre study was performed to determine the response of such BCC to MAL-PDT. METHODS: An open, uncontrolled, prospective, multicentre study was conducted comprising patients with superficial and/or nodular BCC who were at risk of complications, poor cosmetic outcome, disfigurement and/or recurrence using conventional therapy. Patients were given one or two cycles within 3 months of topical MAL-PDT, each consisting of two treatments 1 week apart. Tumour response was assessed clinically at 3 months after the last PDT, with histological confirmation of all lesions in clinical remission. The cosmetic outcome was rated. Patients with a BCC in remission will be followed up for 5 years for recurrence, of which the 24-month follow-up is reported here. Ninety-four patients with 123 lesions were enrolled and treated with MAL-PDT at nine European primary care and referral university hospitals. An independent blinded study review board (SRB) retrospectively excluded nine patients and a total of 15 lesions from the efficacy analysis, for not having a difficult-to-treat BCC according to the protocol. RESULTS: The lesion remission rate at 3 months was 92% (45 of 49) for superficial BCC, 87% (45 of 52) for nodular BCC, and 57% (four of seven) for mixed BCC, as assessed by clinical examination, and 85% (40 of 47), 75% (38 of 51), and 43% (three of seven), respectively, as assessed by histological examination and verified by the SRB. At 24 months after treatment, the overall lesion recurrence rate was 18% (12 of 66). The cosmetic outcome was graded as excellent or good by the investigators in 76% of the cases after 3 months follow-up, rising to 85% at 12 months follow-up, and 94% at 24 months follow-up. CONCLUSIONS: Topical MAL-PDT is effective in treating BCC at risk of complications and poor cosmetic outcome using conventional therapy. MAL-PDT preserves the skin and shows favourable cosmetic results.

Administration, Topical↗
PubMed2002

Aborted genital herpes simplex virus lesions: findings from a randomised controlled trial with valaciclovir.

OBJECTIVES: In prospective trials, episodic valaciclovir significantly increased the chance of preventing or aborting the development of painful vesicular genital herpes simplex virus (HSV) lesions compared with placebo. We explored the clinical outcome of aborted lesions and its association with early treatment in a study designed to compare 3 and 5 days' treatment with valaciclovir. METHODS: In a randomised controlled trial, valaciclovir 500 mg twice daily for 3 or 5 days was initiated at the first symptoms of a genital herpes outbreak. The primary end point was length of episode with pain, HSV shedding, and aborted lesions secondary end points. The effect of time from symptom recognition to treatment initiation on aborted lesions was assessed in a post hoc analysis. RESULTS: In 531 patients, no differences were observed between 3 and 5 days' treatment in episode duration (median 4.7 v 4.6 days), loss of pain/discomfort (2.8 v 3.0 days), or lesion healing (4.9 v 4.5 days). Vesicular lesions were aborted in 27% of patients treated for 3 days v 21% of patients receiving valaciclovir for 5 days. The odds of achieving an aborted episode were 1.93 (95% CI: 1.28 to 2.90) times higher for those initiating treatment with valaciclovir within 6 hours of first sign or symptom. CONCLUSIONS: There was no difference between 3 and 5 days' treatment in reducing episode duration or lesion abortion. Prompt treatment with valaciclovir can abort genital HSV reactivation episodes, preventing a vesicular outbreak. Maximum treatment benefit depends on prompt therapy after recognition of symptoms.

Acyclovir↗
PubMed2001

The molecular determinants of sunburn cell formation.

Sunburn cell (SBC) formation in the epidermis is a characteristic consequence of ultraviolet radiation (UVR) exposure at doses around or above the minimum erythema dose. SBC have been identified morphologically and biologically as keratinocytes undergoing apoptosis. There is evidence that SBC formation is a protective mechanism to eliminate cells at risk of malignant transformation. The level of DNA photodamage is a major determinant of SBC induction by a process controlled by the tumor suppressor gene p53. However, extra-nuclear events also contribute to SBC formation, such as the activation of death receptors including CD95/Fas. UVR triggers death receptors either by direct activation of these surface molecules or by inducing the release of their ligands such as CD95 ligand or tumor necrosis factor. Oxidative stress also appears to be involved, probably via mitochondrial pathways, resulting in the release of cytochrome C. Pathways which modify SBC formation are now extensively studied given the importance of apoptosis in eliminating irreparably damaged cells. A greater understanding of the mechanisms that induce and prevent UVR-induced apoptosis will contribute to our understanding of mechanisms relevant in genomic integrity.

Animals↗
PubMed2001

Solar UVR exposures of indoor workers in a Working and a Holiday Period assessed by personal dosimeters and sun exposure diaries.

BACKGROUND/AIM: The aim of this study was to quantify ultraviolet radiation (UVR) exposure of fully employed indoor workers during a Working Period and a Holiday Period in the summer months. A further aim was to investigate the correlation between individual personal UVR dosimeter reading and self-reported data in a diary about sun exposure habits and to investigate whether skin type, age and gender influence sun exposure. METHODS: The solar UVR, in standard erythema doses (SED) measured by UV sensitive spore-film filter type personal dosimeters (VioSpor), and sun exposure diaries were compared. The study included 44 healthy Danish adult indoor workers during a Working Period of a mean of 13 days and a Holiday Period of a mean of 17 days from June to September. RESULTS: The individual total UVR exposure correlated significantly (P<0.001) in both the Holiday and Working Periods with individual total hours spent outdoors from 07:00 to 19:00 and with skin area exposure hours. There was no significant correlation between sun exposure dose and gender, age or skin type I-IV, or between the individual solar exposure dose in the Working and the Holiday Period. However, subjects with UVR exposures in the upper quartile spent their Holiday Period in Southern Europe, and/or had been more than the mean time outdoors at the beach/sea and/or between 12:00 and 15:00. Subjects with UVR exposure in the lower quartiles spent their holidays in Denmark or Northern Europe and did not stay at the beach at all. They received an average solar UVR dose which was 22% of ambient in Denmark in the same period while subjects having their holidays in Southern Europe received as much as 90% of the ambient dose in Denmark. CONCLUSIONS: Despite information campaigns to avoid the midday sun, on average 35% of the recorded hours outdoors were spent between 12:00 and 15:00 in the Holiday Period. Total hours outdoors give the best estimate of the total sun exposure dose. Registration in a diary of total hours outdoors and whether the Holiday Period was in Northern or Southern Europe can be used to predict the solar exposure dose in a Holiday Period of a few weeks.

Adult↗
PubMed2001

Measurement of the mechanical properties of skin with ballistometer and suction cup.

BACKGROUND: There is no consensus on the methodology for describing the mechanical properties of human skin in vivo. Current descriptions are generally method dependent. METHOD: The mechanical properties of palmar skin of the hypothenar as well as dorsal and ventral forearm skin were studied in 17 healthy volunteers. Two methods were used: ballistometry [Dia-stron Torsional Ballistometer (Diastron Ltd., Andover, UK)] and suction cup [The Dermaflex machine (Cortex Technology, Hadsund, Denmark)]. RESULTS: A moderate degree of correlation was found between the methods (rs=0.315-0.540), while internal correlation between different measures obtained with one method was higher (rs=0.375-0.967). The suction cup method parameters (distensibility and elasticity) correlated significantly with the ballistometry parameters (indentation, alpha, area and coefficient of restitution), while the hysteresis did not correlate to ballistometry parameters. The coefficient of variation of both methods (CV=0.02-0.35) was within the range obtained with other non-invasive methods, e.g., TEWL. Regional differences were identified with both methods, while only the suction cup method identified age-related changes. CONCLUSIONS: The results suggest that while both methods may be useful, they describe related but not identical aspects of skin mechanics. The differences in measuring principle suggest that the suction cup method predominantly measures elasticity, while the ballistometer predominantly appears to measure stiffness. Hysteresis may be a unique measure of skin viscosity. Additional studies, however, are needed to specify the clinical significance of the various measures of skin mechanics.

Biomechanical Phenomena↗