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result to the study done by Tagami and Yoshikuni. They found that there was reduced skin hydration
and increased TEWL in plaque type psoriasis [28]. Based on this study, it seemed that in case of skin
barrier defected, for example; in psoriatic lesion LP could reduce TEWL better than CB. In such as case,
LP is an occlusive which protects the revaporation of water from the psoriasis lesions therefore it
indirectly enhances reduced TEWL more than CB. Meanwhile, CB as mentioned earlier is an humectant.
It absorbs water from underlying dermis into epidermis by which it is increase risk of water loss from
the epidermis to the environment.
ǰ
Comparisons of skin hydration (arbitrary unit, AU) change from baseline between areas applied
with LP and CB in normal skin and psoriasis lesions
Normal skin
: At the end of a 4-week treatment, both studied areas showed significant increase
of skin hydration (p<0.0001) when compared to their baseline values. Comparing the mean difference
values of pre/post treatment from both areas, the mean difference of both studied areas (median
LP-5.04 and CB-4.20 AU) was not different (p=0.810). Based on this study, liquid paraffin (LP) was equal
to cream base (CB) in terms of increase skin hydration. Repeated applications of moisturizers on
normal skin have been reported to increase skin hydration without changing TEWL [29] as the author
has discussed earlier under heading comparison change of TEWL on normal skin.
Psoriasis lesions:
At the end of a 4-week treatment, psoriasis lesions treated with either LP or
CB showed significant increase of skin hydration (p<0.0001, p<0.0001, respectively) when compared to
their baseline values. Comparing the mean difference values of pre/post treatment from both areas,
the mean difference of both studied areas (median LP-2.65 and CB-4.00 AU) there was statistically
significant difference (p=0.006), CB was better than LP in increasing skin hydration on the psoriasis
lesions. CB was classified as emollient. The use of emollient to maintain skin hydration and barrier
function remains the principal treatment for dry skin conditions [30]. Emollients should have effect on
reducing the clinical signs of dryness, such as roughness or scaling, and improving sensations, such as
itching and tightness [31] as it was confirmed that a moisturizer alone (without concomitant medication
use) could decrease skin dryness in patients with psoriasis [18]. Additionally, an emollient was able to
normalize cell proliferation and cell differentiation in psoriatic plaques. [18]. Fluhr, J Cavallotti, C and
Berardesca, E. reported that moisturizers showed wide range of benefit on skin diseases such as to
restore barrier function of the epidermis, to provide a soothing protective layer and to hydrate
epidermis [17].
Conclusion
Psoriasis much affects on a patient’s quality of life. Management strategies including the use of
moisturizers are most important for psoriasis treatment. Moisturizers contribute in the treatment
process by protecting skin barrier function and preventing water loss through the skin. The instrumental
measurement in this study confirmed the effectiveness of LP and CB in treating psoriasis lesions. In
conclusion, cream base showed a better hydrating effect on the psoriasis lesions than liquid paraffin.
