Review of methods used for quantifying excess water in Mandy Fader

advertisement
Skin Research and Technology 2010; 16: 1–8
Printed in Singapore All rights reserved
doi: 10.1111/j.1600-0846.2009.00380.x
r 2010 John Wiley & Sons A/S
Skin Research and Technology
Review of methods used for quantifying excess water in
over-hydrated skin using evaporimetry
Mandy Fader1, Sinead Clarke-O’Neill2, W. K. Rebecca Wong2, Bo Runeman3, Anne Farbrot3 and
Alan Cottenden2
1
Continence Technology and Skin Health Group, School of Health Sciences, University of Southampton, Southampton, UK, 2Continence and Skin
Technology Group, Department of Medical Physics and Bioengineering/Department of Medicine, University College London, London, UK, and 3SCA
Hygiene Products AB, R&D, Göteborg, Sweden
Background: Advances in diapers and skin barrier products are often aimed at reducing water penetration of the
skin to prevent diaper dermatitis and evaporimetry has
commonly been measured to quantify excess water in the
skin. The aim of this study was to critically review the
methods used to measure water vapour flux density
(WVFD) using evaporimetry in order to identify a standardised methodology.
Methods: We used MEDLINE (1980–2008) and hand
searching to identify published papers that used evaporimetry to measure WVFD when the skin has been exposed to
water/saline/urine. We compared the papers with respect to
subjects, sites, methods of hydrating the skin, the conditions
of logging, timing and analysing the evaporimetry data.
Results: We identified 10 papers. Methods and techniques
for measuring WVFD and analysing data varied consider-
ably between studies and it was not possible to identify a
standardised method. The main sources of error and variation are discussed.
Conclusion: Little work has been carried out to establish
the optimum methods and techniques needed to minimise
variation in measurements of WVFD using evaporimetery.
There is a need to develop more robust, standardised
methods and to demonstrate their reliability for further work.
D
penetration of the skin and evaporimetry (use of a
device which measures water evaporation from
the skin) has often been used to quantify excess
water in the skin as an indicator of product
efficacy. Although such evaporimetry measurements have commonly been referred to as transepidermal water loss (TEWL), this term does not
accurately describe measurement of water loss
from the skin which has entered the stratum
corneum externally such as via a wet diaper,
because this water does not pass through the
epidermis. We have therefore limited the use of
the term TEWL to situations where water has
evaporated from the skin surface having entered
the stratum corneum from the tissues below and
have used the term ‘baseline TEWL’ to describe
trans-epidermal water loss under equilibrium conditions. Measurement of baseline TEWL is usually
made either before the skin has been exposed to
occlusion or external water (or both) or after full
recovery from such exposure. We have used the
is a common problem which
affects almost all infants at some time (1)
and up to about 50% of adults wearing incontinence pads (2). Over-hydrated skin is more
easily damaged by friction, and is more vulnerable to chemical irritation and bacterial colonisation than dry skin (3). Based on experimental
work Berg (4) postulated a ‘wet’ skin model of
diaper dermatitis, whereby increased water in the
skin, combined with faecal enzymes and rising
pH lead to the development of dermatitis. In
adults, pressure ulcers are associated with incontinence (5) and the higher coefficient of friction of
over-hydrated skin is believed to contribute to
mechanical abrasion damage (6), particularly
over bony prominences such as the sacrum and
coccyx. Reduction in skin water loading has
therefore been an important goal for manufacturers of diapers and topical barrier products.
Advances in diaper technology and in skin
barrier products are often aimed at reducing water
IAPER DERMATITIS
Key words: diapers – trans-epidermal water loss – skin
hydration – review
& 2009 John Wiley & Sons A/S
Accepted for publication 30 June 2009
1
Fader et al.
general term water vapour flux density (WVFD) to
describe the evaporative loss of water from the
skin surface, whatever its source. The measurement of interest in wet diaper studies is the excess
water in the skin and this is obtained by determining the area under the desorption curve (WVFD
against time), having subtracted baseline TEWL.
We have referred to this as the skin surface water
loss (SSWL) and it is measured in g/m2.
Other methods for measurement of excess
water in the skin exist, such as measurement of
impedence or conductance but these are proxy
measures of water loading and measurement of
water evaporation has the advantage of providing a more fundamental method of quantifying
water in skin. Although the reliability and validity of evaporimetry measurement has been well
described for the purposes of assessing skin
barrier function, and guidance for standardisation has been published (7, 8) much less work has
been published on the method when used to
measure ‘wet’ skin conditions.
Aim
The aim of this study was to critically review the
methods used to measure WVFD using evaporimetry in order to identify a standardised methodology to use for further work.
Methods
We searched the literature using MEDLINE
(1980–2008) to identify papers where evaporimetry had been used to quantify the excess water
penetration of skin following the application of
wet material, with the aim of reviewing the
methodologies used, rather than the outcomes
of the studies. We used hand searching to complete our search.
Results
Ten studies were identified (3, 9–19) and they are
listed in Tables 1 and 2, which summarise their
key features. All used a Servo Med Evaporimeter
(in its various models) (Servo Med AB, Kinna,
Sweden) to measure WVFD.
Zimmerer et al. (3) published the first substantial study to characterise skin that had been over
hydrated by occlusion with wet diaper materials,
and described in some detail the extensive WVFD
measurements they made. Adults and babies
2
were studied using different fluid loadings on
diapers (Dyne solution for babies) and on patches
cut from diapers (urine for adults). WVFD from
their skin was measured on patch/diaper removal. Each measurement involved determining
the maximum WVFD value during a 20-s logging
period. For adults – and a limited number of the
babies – a first WVFD reading was taken immediately after patch removal, followed by periodic
readings until the WVFD returned to its baseline
value (after 15–20 min). WVFD was then plotted
against time – having first subtracted the baseline
TEWL value – and the area under the graph up to
20 min (SSWL) was determined as an estimate of
the excess water in the skin caused by contact
with the wet diaper material. For most of the
babies a single WVFD measurement was taken
2 min after patch removal (when the rate of fall in
the WVFD reading had abated somewhat). Analysis of data from the entire WVFD decay curves
recorded for the minority of babies revealed that
a spot reading at 2 min after diaper removal
correlated quite well with the SSWL up to
20 min, and was much easier to obtain.
Subsequent researchers have based their methods on those used by Zimmerer but there has
been considerable variation in components of the
method. In addition none of these studies appears to have conducted repeat experiments on
the same subjects under the same conditions.
Accordingly, the repeatability of the methodologies used is unknown.
We discuss the main sources of variation below
with a particular focus on the methods of water
loading the skin and the type of WVFD outcome
measure used when measuring the dynamic
status of over-hydrated skin.
Subjects, Sites and Methods of
Hydrating the Skin (Table 1)
Table 1 shows the characteristics of the subjects
included in the studies, the various skin sites
used and the different methods adopted to hydrate the skin. A variety of test fluids was used at
different loadings in patches/products. In most
studies, fluid loading was insufficient to achieve
full saturation in patches/products and, except in
the studies by Hatch et al. (12, 18), Markee et al.
(19) and Cameron et al. (13) there was no attempt
to distribute sub-saturation fluid loading uniformly throughout a test piece. Accordingly, the
environment experienced by skin will have var-
3 knitted fabrics
(1 cotton; 2 polyester)
8 diaper brands;
1 washable;
7 disposable
Volar forearm
Volar forearm
Suprapubic area
and buttock (thigh
for baseline
TEWL)
Volar forearm
33 adults
Unknown gender
5 male adults
1601 infants
Unknown gender
5 male adults
Hatch et al. (1992)
and Markee et al.
(1993)
Berg et al. (1994)
Hatch et al. (1997)
2 different fabrics
Patches cut from 20
brands of incontinence
pads; 3 washable; 17
disposable (10 with
superabsorbent polymer,
7 without)
Patches cut from 16
brands of diapers; 7
washable; 9 disposable
(5 with superabsorbent
polymer, 4 without)
Dallas and Wilson
(1992)
Volar forearm
80 adults
Unknown gender
4 disposable diapers
(2 with superabsorbent
polymer; 2 without)
Patches cut from
1 disposable and
1 cloth diaper
Whole disposable
or cloth diapers
(one variant of each)
Diaper/patch
material
Wilson and Dallas
(1990)
Buttock
Suprapubic area
Volar forearm
Skin site
for measurement
150 infants
Mixed gender
32 male babies
Unknown N adults
Unknown gender
Subjects
Davis et al. (1989)
Expt #2
Zimmerer (1986)
Expt #1
Authors
(year)
TABLE 1. Subjects, sites and methods of hydrating the skin
Occlusive Hilltop
chamber
Not applicable
Occlusive Hilltop
chamber
Knitted wrap
retainer
Elastic mesh
retainer
Not applicable
Not applicable
Elastic mesh
bandage
Patch held
in place by
Distilled
water
Subjects’
own urine
Distilled
water
1% saline
with 0.025%
Triton
1% saline
with 0.025%
Triton
Subjects’
own urine
Dyne solution
Subjects’
own urine
Fluid
2h
7 mL in 6.3 6.3 cm patch
( 5 ‘moderate loading’)
3 3 cm patches immersed in
water, put through ringer with
chromatography paper either side to
give uniform distributions of 35
(PET fabric), 44 or 75 (cotton fabric)
% saturation
30 or 60 min
Variable
1, 2, 5, 10, 20,
30, 45 or 60 min
2h
7 mL in 6.3 6.3 cm patch
( 5 ‘moderate loading’)
38.6% saturated (just cotton); or fully
saturated (all 3 fabrics). For partial
saturation, 3 3 cm patches
immersed in water, put through
ringer with chromatography paper
either side to give uniform
distributions
Whatever infant had voided
Variable
1h
2h
Diaper/patch
wear time
Whatever infant had voided
(measured on diaper removal)
0, 50, 100 or 150 mL
1–6 dry patch
weight
Fluid
load
Review of methods using evaporimetry in over-hydrated skin
3
4
1h
1, 3 or 6 h
Fluid delivered into in situ diaper to
simulate micturition. Fluid loading
level unclear.
3 mL in product centre
Normal
saline
Physiological saline
(except for dry
pads worn for
3 h as controls)
Physiological saline
Whole menstrual pad
with standard or vapourpermeable backing
Elastic mesh
bandage
Methods and Conditions of Logging,
Timing and Analysing WVFD Data
(Table 2)
Expt #2
TEWL, trans-epidermal water loss.
Volar forearm
10 female adults
Suprapubic area
Expt #2
Shafer et al. (2002)
Expt #1
Tape and nylon
netting.
Not applicable
3 disposable diapers
(all with superabsorbent
polymer; one with a
microporous backing,
two without)
Volar forearm
Unknown N
female adults
Unknown N
infants
Mixed gender
Grove et al. (1998) and
Akin et al. (1997)
Expt #1
ied with position beneath a given patch, and from
patch-to-patch in different experiments under
nominally identical conditions. Likewise, diapers
which were loaded naturally by their infant
wearer may have varied greatly in the environment they provided for occluded skin, depending
on how much urine the infant voided and when.
Although such methods have often proved
capable of detecting gross differences between
products (e.g. diapers with and without superabsorbent polymers) a more reliable way of
hydrating the skin is needed to examine the
repeatability of WVFD measurements.
3h
40 min
2.5 2.5 cm patches immersed in
water, put through ringer with
chromatography paper either side to
give uniform distribution
Occlusive Hilltop
chamber
16 different fabrics
35 female
adults
Cameron et al.
(1997)
Volar forearm
Subjects
Authors
(year)
TABLE 1. Continued
Skin site
for measurement
Diaper/patch
material
Patch held
in place by
Distilled
water
Fluid
Fluid
load
Diaper/patch
wear time
Fader et al.
Perhaps most importantly, the procedure for
logging WVFD data and processing it to obtain
some measure of skin wetness has varied greatly
between studies (Table 2). This is most easily
reviewed by considering an example WVFD
drying curve for very wet skin (Fig. 1). Following
the initial delay in machine response, evaporation of water from the surface of the skin dominates, resulting in the high value, low gradient
portion of the curve. If the skin is not very wet or
surface water has been blotted away before data
logging, this element of the curve may be much
shorter or completely absent. Once surface water
has evaporated, water loss from within the stratum corneum dominates and, as the stratum
corneum dries out, the WVFD value falls –
initially very rapidly – until the baseline TEWL
level recorded for the skin before over-hydration
is reattained.
WVFD measurement in the reviewed studies
varied from recording the maximum value 2 min
after patch removal (minus the baseline TEWL)
(12) to measuring WVFD repeatedly over time,
constructing the desorption curve and measuring
the SSWL (the area under the curve above the
baseline measurement) (3). The approach of Zimmerer et al. (3) – who recorded the whole desorption curve and measured the area beneath it
having subtracted baseline TEWL – would seem
to be the most robust and defensible on theoretical grounds, although their decision to log
WVFD for only 20 s per reading is likely to have
introduced substantial errors. Other approaches
were probably developed primarily to reduce the
time and difficulty of capturing whole desorption
Review of methods using evaporimetry in over-hydrated skin
B
90
WVFD (gm–2h–1)
A
60
C
30
Baseline
TEWL
0
0
500
1000
Time (s)
1500
2000
Fig. 1. Example desorption curve for very wet skin. (A) Initial rapid increase in trace due to response time of machine. (B) Surface water evaporating.
(C) WVFD value falls as the stratum corneum dries out. WVFD, water vapour flux density; TEWL, trans-epidermal water loss.
curves – especially for measurements on infants.
Taking measurements immediately after patch
removal is particularly problematic as the desorption curve is changing very rapidly then (Fig. 1)
and so readings will depend critically on the
quantity of surface water on the skin (if any),
the length of any delay before starting to log data,
the time for which data are logged, and the way
the data are processed; for example, the mean
and maximum values over a period when WVFD
is falling rapidly will differ greatly.
Another important factor is that the Servo Med
Evaporimeter probe is known to take of the order
of 30–45 s to achieve a stable reading in measuring WVFD under equilibrium conditions on the
volar forearm and palm (20, 21). It seems unlikely
that it will deliver reliable readings in less than
this time under the non-equilibrium conditions
associated with skin drying curves. Accordingly,
the 2 min logging period chosen for most wet
skin studies is likely to have been too short. For
some work the logging period was 30 s or less (3,
12), a practice likely to have yielded particularly
inaccurate data. Notably, Cameron et al. (13)
logged for 2 min but discarded data from the first
30 s of logging.
Other Sources of Variation
None of the studies appears to differentiate
between surface water on the stratum corneum
and water held within the stratum corneum: in
general, Evaporimeter readings taken soon after
patch/product removal are likely to have included some water coming from each of these
two sources (Fig. 1). In another study of the
impact of initially dry fabrics on skin worn under
hot humid conditions, Hatch (1990) (22) addressed this issue by blotting sweat from the
skin surface before logging WVFD.
Subject, Environmental and Instrument
Variables
Tables 1 and 2 give the variables that are known
to be sources of variation according to published
guidelines for measuring baseline TEWL to characterise skin barrier function (rather than to
quantify excess water in the skin) (7, 8). Variables
have been usefully classified as (i) person-linked,
(ii) environmental and (iii) instrumental (8). Some
of the studies predated these guidelines and in
others some variables were unreported, but in
general, more recent studies have followed them
more closely. The guidelines indicate that the
anatomical site for TEWL measurement should
be specified precisely as TEWL varies considerably over the surface of the body. In particular,
there is some evidence that baseline TEWL may
vary between dominant and non-dominant arms
(23, 24) although some have found no difference
(25, 26). Similarly, there is evidence for TEWL
varying with position on the volar forearm (24, 27),
although some have found little variation, pro-
5
Fader et al.
TABLE 2. Methods and conditions of logging, timing and analysing evaporimetry data
Authors
(year)
Temp
(RH)
Acclimatisation
time
Timing of evaporimeter
measurement(s)
Outcome variable(s)
calculated
Zimmerer (1986)
Expt #1
Unknown
Unknown
‘Precise intervals’ until baseline
reached ( 20 min). Maximum
reading over 20 s taken as
WVFD value
Area under curve above baseline
Expt #2
Unknown
Unknown
First at 2 min after patch
removal, then periodically until
baseline reached ( 15 min).
Maximum reading over 20 s
taken as WVFD value
Value at 2 min after patch
removal (primarily)
Davis et al.
(1989)
Unknown
Unknown
Data logged at 1 Hz for 2 min
straight after diaper removal
Area under drying curve
over first 2 min (apparently without
subtracting baseline TEWL)
Wilson and Dallas
(1990)
751F (241C)
40%
Unknown
First reading over 2 min straight
after patch removal. Six further
2 min readings, each separated
by 2 min rest. Means over each
2 min taken as WVFD value
Difference between
1st and 6th Evaporimeter
reading 5 ESW
Dallas and Wilson
(1992)
741F (231C)
42%
Unknown
Data logged for 2 min, starting
2 min after patch removal;
second 2 min WVFD after 2 min
rest. Baseline TEWL (on
adjacent skin) taken between
two other readings. Means
over each 2 min taken as
WVFD value
Difference between
2nd ‘wet’ Evaporimeter
reading and baseline 5 ESW
Hatch et al. (1992)
and Markee et al.
(1993)
211C
65%
Dry skin: 30 min;
80% hydrated skin:
1h
Data logged for 30 s, starting
2 min after patch removal.
Highest value during 30 s noted
Difference between maximum
from 30 s log after ‘treatment’
minus (mean) baseline value
Berg et al. (1994)
Unknown
Unknown
Immediately after diaper
removal and at 60 and 120 s
Hatch et al. (1997)
211C
65%
30 min
Cameron et al.
(1997)
201C
65%
10 min
Data logged for 30 s, starting
2 min after patch removal.
Maximum reading during 30 s
taken as WVFD value
1 reading of 2 min taken
immediate after patch removal,
but discarded first 30 s of data.
Mean taken as WVFD value
Mean of data at all times and both
locations (pubis and buttock)
minus baseline 5 skin wetness
Maximum value minus background
(on adjacent skin) 5 Change in
EWL
221C 40%
Unknown 22C
Unknown 40%
15 min
Unknown
251C
50%
201C, 30%
251C, 50%
301C, 75%
30 min
Grove et al. (1998)
and Akin et al. (1997)
Expt #1
Expt #2
Shafer et al. (2002)
Expt #1
Expt #2
Notes
Mean minus baseline
(taken on nearby skin)
4 h minimum
between test
and retest
Baseline: mean over last 15 s
of 30 s logging period. After
diaper removed: mean of 2 min
logging period or ? repeats
over various intervals over
5 min period ignoring first 10 s
Mean minus baseline TEWL
Probe holder used
Plexiglas dome used
for baseline infant
measurements to
reduce effects of
air currents
Immediately after patch
removal, data logged for 45 s
where centre of pad (with fluid
loading) was
Maximum value between
15 and 45 s. Baseline
TEWL not subtracted
ESW, excess skin wetness; EWL, excess water loss; WVFD, water vapour flux density; TEWL, trans-epidermal water loss.
vided the skin near the wrist and elbow creases is
avoided (25, 28, 29). TEWL also varies with skin
temperature and so the ambient temperature
should be noted and subjects should be acclima-
6
tised to ambient conditions for at least 15–30 min
before measurements are made (8). Furthermore,
when an ambient temperature probe is placed on
the skin, the TEWL reading increases as the probe
Review of methods using evaporimetry in over-hydrated skin
warms to skin temperature ( 30 1C). For a
Tewameters probe (Courage and Khazaka, Köln,
Germany) this has been shown (25, 30) to take 1015 mins (which is similiar to that of the Servo Med
device) and to be accompanied by a TEWL reading
change of about 0.6 g/m2/h/ 1C (30). Mathias et al.
(31) have provided a formula for normalising
TEWL to a skin temperature of 30 1C, which
some have adopted for studies of over-hydrated
skin (12, 13). The temperature of the investigator’s
hand can also affect readings from the hand-held
probe and some have suggested that (s)he should
wear an insulating glove (32) or that the probe
should be held by a clamp instead (33).
Physical, thermal and emotional sweating
should also be controlled and so subjects should
be calm and the ambient temperature such as to
avoid both shivering and excessive sweating (34):
20–22 1C is recommended (7, 8). Ambient humidity
also affects TEWL and 40% RH (7) and up to
50% RH (8) have been recommended. It is also
known that TEWL is affected by draughts, which
should be minimised and some have advocated the
use of shields around the probe (7, 8, 14, 16, 35). It is
recommended that the probe is held horizontal for
measurements (7, 8). Care should also be taken
with the pressure of the probe against the skin:
Barel and Clarys (30) found that increasing the load
on the Servo Med Evaporimeter probes from 100g
to 300 g force increased TEWL readings by about
10%.
Conclusion
It is evident from this review that techniques and
methods have varied widely in studies on overhydrated skin and that a robust methodology
needs to be established for further work. Furthermore work to date has been confined to experiments on adult volar forearms or babies’ bottoms
although an important target patient group
for the development of better products to
reduce skin damage from over hydration is older
people and the target anatomical site is the skin
within an incontinence pad (i.e. buttocks, hips
and groins).
Acknowledgements
The authors would like to thank SCA Hygiene
Products AB (Sweden), the Smith and Nephew
Foundation (UK) and the Engineering and Phy-
sical Science Research Council for supporting this
work.
References
1. Ward DB, Fleischer AB, Feldman SR, Krowchuk DP.
Characterization of diaper dermatitis in the United
States. 2000; 154: 943–946.
2. Gray M, Bliss DZ, Doughty DB, Ermer-Seltun J, Kennedy-Evans KL, Palmer MH. Incontinence-associated
dermatitis: a consensus. J Wound Ostomy Continence
Nurs 2007; 34: 45–54.
3. Zimmerer RE, Lawson KD, Calvert CJ. The effects of
wearing diapers on skin. Pediatr Dermatol 1986; 3: 95–
101.
4. Berg RW. Etiology and pathophysiology of diaper dermatitis. Adv Dermatol 1988; 3: 75–98.
5. Spector WD, Fortinsky RH. Pressure ulcer prevalence in
Ohio nursing homes: clinical and facility correlates. J
Aging Health 1998; 10: 62–80.
6. Sivamani RK, Goodman J, Gitis NV, Maibach HI. Friction coefficient of skin in real-time. Skin Res Technol
2003; 9: 235–239.
7. Pinnagoda J, Tupker RA, Agner T, Serup J. Guidelines
for transepidermal water loss (TEWL) measurement. A
report from the Standardization Group of the European
Society of Contact Dermatitis. Contact Dermatitis 1990;
22: 164–178.
8. Rogiers V. EEMCO guidance for the assessment of
transepidermal water loss in cosmetic sciences. Skin
Pharmacol Appl Skin Physiol 2001; 14: 117–128.
9. Davis JA, Leyden JJ, Grove GL, Raynor WJ. Comparison
of disposable diapers with fluff absorbent and fluff plus
absorbent polymers: effects on skin hydration, skin pH,
and diaper dermatitis. Pediatr Dermatol 1989; 6: 102–
108.
10. Dallas M J, Wilson PA. Adult incontinence products:
performance evaluation on healthy skin. INDA J Nonwovens Res 1992; 4: 26–32.
11. Wilson PA, Dallas MJ. Diaper performance: maintenance
of healthy skin. Pediatr Dermatol 1990; 7: 179–184.
12. Hatch KL, Prato HH, Zeronian SH, Maibach HI. In vivo
cutaneous and preceived comfort response to fabric Part
VI: the effect of moist fabrics on stratum corneum
hydration. Textile Res J 1997; 67: 926–931.
13. Cameron B A, Brown A M, Dallas M J, Brandt B. Effect of
natural and synthetic fibers and film and moisture
content on stratum corneum hydration in an occlusive
system. Textile Res J 1997; 67: 585–592.
14. Grove GL, Lemmen JT, Garafalo M, Akin FJ. Assessment
of skin hydration caused by diapers and incontinence
articles. Curr Probl Dermatol 1998; 26: 183–195.
15. Berg RW, Milligan MC, Sarbaugh FC. Association of skin
wetness and pH with diaper dermatitis. Pediatr Dermatol 1994; 11: 18–20.
16. Akin FJ, Lemmen JT, Bozarth DL, Garafalo MJ, Grove
GL. A refined method to valuate diapers for effectiveness in reducing skin hydration using the adult forearm.
Skin Res Technol 1997; 3: 173–176.
17. Schafer P, Bewick-Sonntag C, Capri MG, Berardesca E.
Physiological changes in skin barrier function in relation
to occlusion level, exposure time and climatic conditions. Skin Pharmacol Appl Skin Physiol 2002; 15: 7–19.
18. Hatch KL, Markee NL, Prato HH et al. In vivo cutaneous
and perceived comfort response to fabric. Part V: effect
of fiber type and fabric moisture content on stratum
corneum hydration. Textile Res J 1992; 62: 638–647.
7
Fader et al.
19. Markee NL, Hatch KL, Prato HH, Zeronian SH, Maibach
HI. Effect of fiber type and fabric moisture content on
the hydration state of human stratum corneum. J Therm
Biol 1993; 18: 421–427.
20. Blichmann CW, Serup J. Reproducibility and variability
of transepidermal water loss measurement. Studies on
the Servo Med evaporimeter. Acta Derm Venereol 1987;
67: 206–210.
21. Hatch KL, Wilson DR, Maibach HI. Fabric-caused
changes in human skin: in vivo stratum corneum water
content and water evaporation. Textile Res J 1987; 57:
583–591.
22. Hatch KL, Markee NL, Maibach HI, Barker RL, Woo SS,
Radhakrishnaiah P. In vivo cutaneous and perceived
comfort response to fabric. Part III: water content and
blood flow in human skin under garments worn by
exercising subjects in a hot, humid environment. Textile
Res J 1990; 60: 510–519.
23. Treffel P, Panisset F, Faivre B, Agache P. Hydration,
transepidermal water loss, pH and skin surface parameters: correlations and variations between dominant
and non-dominant forearms. Br J Dermatol 1994; 130:
325–328.
24. Rodrigues LM, Pereira L. Basal transepidermal water
loss: right/left forearm difference and motoric dominance. Skin Res Technol 1998; 4: 135–137.
25. Rogiers V. Transepidermal water loss measurements in
patch test assessment: the need for standardisation. Curr
Probl Dermatol 1995; 23: 152–158.
26. Oestmann E, Lavrijsen AP, Hermans J, Ponec M. Skin
barrier function in healthy volunteers as assessed by
transepidermal water loss and vascular response to
hexyl nicotinate: intra- and inter-individual variability.
Br J Dermatol 1993; 128: 130–136.
27. Panisset F, Treffel P, Faivre B, Lecomte PB, Agache P.
Transepidermal water loss related to volar forearm sites
in humans. Acta Derm Venereol 1992; 72: 4–5.
28. Pinnagoda J, Tupker RA, Smit JA, Coenraads PJ, Nater
JP. The intra-individual and inter-individual variability
and reliability of trans-epidermal water-loss measurements. Contact Dermatitis 1989; 21: 255–259.
8
29. Pinnagoda J, Tupker RA, Coenraads PJ, Nater JP. Comparability and reproducibility of the results of water-loss
measurements – a study of 4 evaporimeters. Contact
Dermatitis 1989; 20: 241–246.
30. Barel AO, Clarys P. Study of the stratum corneum
barrier function by transepidermal water loss measurements: comparison between two commercial instruments: Evaporimeter and Tewameter. Skin Pharmacol
1995; 8: 186–195.
31. Mathias CG, Wilson DM, Maibach HI. Transepidermal
water loss as a function of skin surface temperature. J
Invest Dermatol 1981; 77: 219–220.
32. Agner T, Serup J. Time course of occlusive effects on skin
evaluated by measurement of transepidermal water loss
(TEWL). Including patch tests with sodium lauryl sulphate and water. Contact Dermatitis 1993; 28: 6–9.
33. Pinnagoda J, Tupker RA, Coenraads PJ, Nater JP. Comparability and reproducibility of the results of water-loss
measurements – a study of 4 evaporimeters. Contact
Dermatitis 1989; 20: 241–246.
34. Pinnagoda J, Tupker RA, Coenraads PJ, Nater JP. Comparability and reproducibility of the results of water-loss
measurements - a study of 4 evaporimeters. Contact
Dermatitis 1989; 20: 241–246.
35. Pinnagoda J, Tupker RA. Measurement of the transepidermal water loss. In: Serup J, Jemec GBE, eds. Handbook of non-invasive methods and the skin. Florida:
CRC Press, 1995: 173–178.
Address:
Mandy Fader RN, PhD
Continence Technology and Skin Health Group
School of Health Sciences
University of Southampton
Highfield, SO17 1BJ
UK
Tel: 144 23 8059 7979
Fax: 144 23 8059 8909
e-mail: mf@soton.ac.uk
Download