A novel
in vivo model for evaluating agents that protect
against ultraviolet A-induced
photoaging.
Takeuchi T; Uitto J; Bernstein EF
Department of Dermatology, Jefferson Institute of
Molecular Medicine, Thomas Jefferson University,
Philadelphia, Pennsylvania 19107, USA.
J Invest Dermatol (United States) Apr 1998, 110
(4) p343-7
Increasing evidence demonstrates that
ultraviolet A radiation (UVA) contributes to
photoaging, which results in the accumulation of
massive amounts of abnormal elastic material in
the dermis of photoaged skin. To study UVA-induced
photoaging in an in vivo system, we utilized a
line of transgenic mice containing the human
elastin promoter linked to a chloramphenicol
acetyl transferase reporter gene. Our prior work
demonstrates promoter activation in response to
ultraviolet B radiation (UVB), UVA, and psoralen
plus ultraviolet A radiation in the skin of these
mice. The addition of psoralen (8-MOP) prior to
administration of UVA results in substantial
increases in promoter activation, as compared with
UVA alone. To demonstrate the utility of these
mice as a model of UVA-induced photodamage, we
administered four lotions to the skin of our
transgenic mice that included: a sunscreen
containing octyl methoxycinnamate and
benzophenone-3 with a sun protection factor (SPF)
of 15, the UVA filter butyl
methoxydibenzoylmethane, the SPF 15 sunscreen and
the UVA filter together, and the lotion vehicle
alone. Following sunscreen administration, mice
received a single psoralen plus ultraviolet A
radiation treatment. All sunscreens decreased
chloramphenicol acetyl transferase activity with
the SPF 15 sunscreen , the UVA filter, and the
combination SPF 15 sunscreen and UVA filter,
resulting in increasing degrees of protection
against psoralen plus ultraviolet A radiation.
These results demonstrate that this model
functions as a rapid and sensitive model of UVA
photodamage for the identification and comparison
of compounds that protect against UVA-induced
photoaging.
Complications of laser resurfacing.
Methods of prevention and management.
Fulton JE Jr
Dermatol Surg (United States) Jan 1998, 24 (1)
p91-9
BACKGROUND: Modern skin resurfacing began with
wire brush surgery. The short-pulse carbon dioxide
(CO2) lasers provide an alternative approach for
facial rejuvenation. However, the potential for
the same complications exist.
OBJECTIVES: To review the more common
complications, the reasons for their development,
and their possible avoidance.
METHODS: After pre-op evaluation and skin
conditioning, a protocol for resurfacing was
followed with standardized settings on the
Ultrapulse CO2 laser. On the glabrous skin 300 mJ
of energy and 60 W of power were used. On the
eyelid skin the settings were reduced to 250 mJ
and 50 W. After three passes with the Computer
Pattern Generator (CPG), a semi-occlusive dressing
was applied for the first 5 days after surgery.
Then, a bland petrolatum ointment was applied for
an additional 5 days. Finally, a moisturizer with
sunscreen or a bleaching cream was used.
RESULTS: It was possible at these energy
fluences to avoid excessive collagen denaturation
and to facilitate wound healing with occlusive
dressing. However, complications still occurred.
Examples of these are presented in detail.
CONCLUSION: Complications can be minimized with
patient education, using optimal laser settings,
applying occlusive dressings, and recognizing
pending problems early.
Effectiveness of antioxidants
(vitamin C and E) with and without sunscreens as
topical photoprotectants.
Darr D; Dunston S; Faust H; Pinnell S
North Carolina Biotechnology Center, Raleigh,
N.C., USA.
Acta Derm Venereol (Norway) Jul 1996, 76 (4)
p264-8
Considerable interest has been recently
generated concerning the use of natural compounds,
anti-oxidants in particular, in photoprotection.
Two of the best known anti-oxidants are vitamins C
and E, both of which have been shown to be
somewhat effective in different models of
photodamage. Very little has been reported,
however, on the effectiveness of a combination of
the two (known to be biologically the more
relevant situation); nor have there been detailed
studies on the ability of these antioxidants to
augment commercial sunscreen protection against UV
damage. We report that (in swine skin) vitamin C
is capable of additive protection against acute
UVB damage (sunburn cell formation) when combined
with a UVB sunscreen . A combination of both
vitamins E and C provided very good protection
from a UVB insult, the bulk of the protection
attributable to vitamin E. However, vitamin C is
significantly better than vitamin E at protecting
against a UVA-mediated phototoxic insult in this
animal model, while the combination is only
slightly more effective than vitamin C alone. When
vitamin C or a combination of vitamin C and E is
formulated with a commercial UVA sunscreen
(oxybenzone), an apparently greater than additive
protection is noted against the phototoxic damage.
These results confirm the utility of anti-oxidants
as photoprotectants but suggest the importance of
combining the compounds with known sunscreens to
maximize photoprotection.
Synergistic topical photoprotection
by a combination of the iron chelator
2-furildioxime and sunscreen.
Bissett DL; McBride JF
Miami Valley Laboratories, Procter & Gamble
Company, Cincinnati, OH 45253-8707, USA.
J Am Acad Dermatol (United States) Oct 1996, 35
(4) p546-9
BACKGROUND: Iron is a factor in skin
photodamage, apparently by way of its
participation in oxygen radical production.
Certain topical iron chelators are
photoprotective.
OBJECTIVE: Our purpose was to determine the
level of topical photoprotection provided by the
iron chelator 2-furildioxime (FDO) in combination
with sunscreen in short- and long-term
photoprotection models.
METHODS: Guinea pigs were treated topically
with FDO, sunscreen , and a combination of the two
and were then exposed to varying doses of UV
radiation to determine the sun protection factor
(SPF). Hairless mice were treated topically with
FDO, sunscreen , and a combination of the two and
then subjected to long-term exposure to a
suberythemal dose of UV radiation. The mice were
evaluated for skin wrinkling and skin tumors.
RESULTS: In guinea pigs, topical FDO combined
with sunscreen provided more than additive
protection; 5% FDO alone provides approximately
SPF 4, whereas 5% FDO combined with an SPF 4
sunscreen product yielded an SPF of more than 30.
In hairless mice exposed long term to UV
radiation, 5% FDO and sunscreen delayed tumor
onset by a mean of 8 and 12 weeks, respectively.
The combination of FDO and sunscreen delayed tumor
onset by a mean of 58 weeks. A similar more than
additive level of protection was observed for skin
wrinkling.
CONCLUSION: Topical FDO combined with sunscreen
is a potent photoprotection system against both
short- and long-term UV radiation exposure.
A review
of skin ageing and its medical
therapy.
Gilchrest BA
Department of Dermatology, Boston University
School of Medicine, MA 02118, USA.
Br J Dermatol (England) Dec 1996, 135 (6)
p867-75
Intrinsic (chronological) skin ageing is
characterized by atrophy of the skin with loss of
elasticity and slowed metabolic activity. The
superposition of environmental damage,
particularly exposure to ultraviolet radiation
(photodamage), on the intrinsic ageing process
results, at least initially, in a hypertrophic
repair response, with a thickened epidermis and
increased melanogenesis. Even more striking
changes occur in the dermis: massive elastosis
(deposition of abnormal elastic fibres), collagen
degeneration, and twisted, dilated
microvasculature. Regular use of a sunscreen alone
appears to allow some repair as well as protection
from further photodamage. Topical tretinoin has
been shown to partially reverse the clinical and
histological changes induced by the combination of
sunlight exposure and chronological ageing. A
formulation of tretinoin in an emollient cream
(Retinova, Renova), developed specifically for the
treatment of photodamaged skin, has been
extensively investigated in multicentre,
double-blind trials and has been shown to produce
significant improvement within 4-6 months of daily
use, compared with vehicle alone, as part of a
regimen including sun protection and moisturizer
use. Histological changes in the epidermis and
dermis noted after 12 months suggest tretinoin
repairs photodamage by reconstitution of the rete
pegs, repair of keratinocyte ultrastructural
damage, more even distribution of melanocytes and
melanin pigment, deposition of new papillary
dermal collagen, and improvements in vasculature.
Alpha-hydroxy acids (AHAs) have also been widely
used for therapy of photodamaged skin, and these
compounds have been reported to normalize
hyperkeratinization and increase viable epidermal
thickness and dermal glycosaminoglycans content.
The single randomized controlled study now
available appears to substantiate AHA efficacy and
safety. In summary, recent work has substantially
elucidated the ageing processes that affect the
skin and has demonstrated that many of the
unwanted changes can be improved by topical
therapy. (50 Refs.)
Sun
exposure and skin disease.
Taylor CR; Sober AJ
Department of Dermatology, Harvard University,
Massachusetts General Hospital, Boston 02114,
USA.
Annu Rev Med (United States) 1996, 47 p181-91
Sunlight exposure produces a variety of adverse
cutaneous effects. Erythema, photosensitivity, and
immunologic alterations represent acute events,
whereas photoaging and carcinogenesis are
long-term consequences. These adverse cutaneous
sequelae can be minimized by photoprotection in
the form of sun avoidance, regular cover-up with
clothing, and sunscreen application. This chapter
reviews the diagnosis and treatment of sun-related
skin disorders and recommendations for reducing
photodamage. (40 Refs.)
Current
concepts. Photoprotection.
Kaminester LH
Department of Dermatology and Cutaneous Surger,
University of Miami (Fla), USA.
Arch Fam Med (United States) May 1996, 5 (5)
p289-95
Photoprotection encompasses all methods to
prevent UV radiation (UVR) damage to the skin,
including sunscreens, clothing, seeking shade, and
duration and time of the day spent outdoors under
UVR. As scientific research validates short- and
long-term detrimental effects of UVR, physicians
and the public must become increasingly aware of
these problems to avoid them. Photoaging is
defined. Choice of sunscreens, their Food and Drug
Administration labeling, and future sunscreen
products are reviewed. Hazards of UVR on the skin
include acute sunburn, photocarcinogenesis,
immunologic suppression, and photoaging.
Distinguishing between UV-A and UV-B damage to the
skin is discussed. Education of physicians and
their patients is crucial to reduce future
photodamage to our population, especially with a
reduction of the ozone layer and with patients
having more free time. The complete skin
examination is emphasized as a method to detect
photodamaged skin and give patients insight to
provide themselves with future photoprotection. A
summary of advice for patients is provided for
physicians to give to their patients. (135
Refs.)
The
effects of chronic sunscreen use on the histologic
changes of dermatoheliosis
Boyd AS; Naylor M; Cameron GS; Pearse AD;
Gaskell SA; Neldner KH
Department of Medicine, Vanderbilt University,
Nashville, TN 37232-5227, USA.
J Am Acad Dermatol (United States) Dec 1995, 33
(6) p941-6
BACKGROUND: Sunscreen application to the skin
of hairless mice is effective in reversing the
histologic changes associated with photoaging
(solar elastosis, epidermal thickening, collagen
depletion, glycosaminoglycan deposition). These
reparative processes have not been studied in
human beings.
OBJECTIVE: The aim of this study was to
evaluate histologically the effects of daily
application of a UVA/UVB sunscreen versus
placebo.
METHODS: We examined 46 patients who were given
either sunscreen or vehicle and asked to apply it
daily for 24 months. Punch biopsy specimens were
obtained from preauricular skin at 0, 12, and 24
months. Each specimen was examined for epidermal
thickening and organization and dermal
inflammatory infiltrate by light microscopy.
Computer-generated analysis of tissue sections was
used to evaluate solar elastosis.
RESULTS: A significant difference in solar
elastosis was found between the treatment groups;
however, the other features remained largely
unchanged.
CONCLUSION: The dermal changes of photoaging
may be affected differently than epidermal changes
when UV radiation exposure is diminished. UVA and
UVB may contribute diversely to these cutaneous
changes. Computer-generated evaluation of
dermatoheliosis may be more accurate than visual
inspection.
Effect of
a conjugated oestrogen (Premarin) cream on ageing
facial skin. A comparative study with a placebo
cream.
Creidi P; Faivre B; Agache P; Richard E;
Haudiquet V; Sauvanet JP
Service de Dermatologie I, Centre Hospitalier et
Universitaire, Hopital Saint-Jacques, Besancon,
France.
Maturitas (Ireland) Oct 1994, 19 (3) p211-23
The effects of Premarin cream on ageing facial
skin were studied in a randomised, double-blind,
parallel group study. Fifty-four women aged 52-70
years who had moderate to severe facial cutaneous
ageing, applied 1 g of either Premarin cream
(0.625 mg conjugated oestrogens per gram of
cream), or placebo cream (same composition with
the exclusion of conjugated oestrogens) to the
face nightly for 24 weeks. Each morning these
women protected their face with a sunblock SPF 15.
Skin thickness was measured by B-scan ultrasonic
echography, and skin microrelief by profilometry.
Each subject's facial appearance was also
evaluated by the subject herself and by the
clinician. A statistically significant difference
(P = 0.013) in favour of Premarin cream was
detected in skin thickness at week 24. Skin
thickness (dermal plus epidermal) for the women
who used Premarin cream increased from 1.56 +/-
0.20 mm at baseline to 1.68 +/- 0.19 mm, compared
with 1.52 +/- 0.20 mm at baseline to 1.59 +/- 0.19
mm in the placebo group. Premarin cream was also
significantly more effective than placebo cream in
improving fine wrinkles according to the results
at weeks 12 and 24 (P = 0.010 and P = 0.012,
respectively). Significant improvement from
baseline was detected in both groups for
roughness, laxity and mottled pigmentation and/or
lentigines; however, there was no significant
difference in these parameters between the two
treatment groups. No subjects discontinued
treatment for a safety reason. In conclusion,
Premarin cream produced better results than the
placebo cream; the difference was statistically
significant for skin thickness and fine wrinkles.
Premarin cream was well tolerated locally, and its
general safety was good.
Sunbathing: college students'
knowledge, attitudes, and perceptions of
risks.
Vail-Smith K; Felts WM
Health, Physical Education, Recreation, and
Safety Program, East Carolina University,
Greenville, North Carolina.
J Am Coll Health (United States) Jul 1993, 42 (1)
p21-6
This study assessed the knowledge, attitudes,
and behaviors of college students regarding
intentional sun exposure (sunbathing). Results are
based on responses of 296 Caucasian students to
the Sun and Skin Inventory. Frequent sunbathers
were more likely than infrequent sunbathers to be
women and to report fewer self-perceived risk
factors, and were less likely to use sunscreen .
They were also more likely to believe that they
look better with a tan, that suntanned skin is
more attractive, and that suntans look healthy.
Forty-three percent of the female respondents and
61% of the men rarely, if ever, used sunscreens,
and only 9% of all respondents reported they used
sunscreens with every intentional sun exposure of
30 minutes or longer. These results suggest that
concern with attractiveness appears to be a major
motivation for frequent intentional sun exposure.
Consequently, educational strategies that stress
health outcomes only may be less effective than
those that also stress photoaging, the detrimental
cumulative effect to appearance of suntanning.
Photoaging and the skin. The effects
of tretinoin.
Green LJ; McCormick A; Weinstein GD
Department of Dermatology, University of
California, Irvine.
Dermatol Clin (United States) Jan 1993, 11 (1)
p97-105
The appearance of photoaged skin is
cosmetically unacceptable to many in our society.
Ostensibly, avoidance of ultraviolet light and
sunlight from early childhood is most desirable
but not likely to happen in our culture. Tretinoin
is the only pharmacologic compound shown to
partially reverse some signs of photoaging.
Improvement with tretinoin therapy has been
quantified clinically and histologically. A major
degree of improvement occurs in 6 to 12 months,
and maintenance treatment one to three times per
week may continue this response. Tretinoin therapy
should optimally be used with daily moisturizer
and sunscreen applications. Psychosocial benefits
of tretinoin therapy, use of tretinoin for
intrinsically aged or non-Caucasian skin, and
higher-strength tretinoin therapy for severely
photoaged skin need to be further explored. It is
possible that some subsets of patients with
photoaged skin may respond better than others. (25
Refs.)
In vivo
evaluation of photoprotection against chronic
ultraviolet-A irradiation by a new sunscreen
Mexoryl SX.
Fourtanier A; Labat-Robert J; Kern P; Berrebi
C; Gracia AM; Boyer B
L'OREAL, Laboratoire de Recherche Fondamentale,
Aulnaysous-bois, France.
Photochem Photobiol (England) Apr 1992, 55 (4)
p549-60
In a previous study on the hairless mouse it
was shown that sub-erythemal doses of pure UV-A
enhanced the numerous changes normally observed
during chronological aging. A new sunscreen (a
bis-benzylidene campho sulfonic acid derivative)
has been synthesized in our research laboratory
(lambda max: 345 nm, epsilon: 47,000). Its
photoprotective properties against UV-A induced
damages were assessed in our mouse model. Three
month old albino hairless mice were exposed for 1
y to suberythemal doses (35 J/cm2) of UV-A
obtained from a xenon source filtered through a WG
345 filter. One group of animals was exposed
untreated, the other received a formulation
containing 5% of the sunscreen prior to
irradiation. At the end of the study the cutaneous
properties of protected mice were compared to
those of unprotected animals and to 3 and 15 month
old unirradiated controls. We found that the
visible changes induced by UV-A irradiation were
mainly sagging and wrinkling. Histological and
electron microscopic alterations consisted of
hyperkeratosis, increased density of elastic
fibers with alteration of fiber orientation and
increased glycosaminoglycan deposits. Biochemical
changes consisted of decreases in total collagen
and collagen hydroxylation and increases in both
collagen III/I + III ratio and fibronectin
biosynthesis. All these changes were reduced or
abolished by the sunscreen .
Photoprotective effects of sunscreens
in cosmetics on sunburn and Langerhans cell
photodamage.
Elmets CA; Vargas A; Oresajo C
Department of Dermatology, Case Western Reserve
University, Cleveland, Ohio.
Photodermatol Photoimmunol Photomed (Denmark) Jun
1992, 9 (3) p113-20
It has become common practice to add
sunscreening agents of variable potency to
cosmetics to protect against the adverse effects
of ultraviolet (UV) radiation exposure. The
purpose of this study was to determine whether
cosmetic preparations containing sunscreening
agents protected against the adverse effects of
acute UV radiation exposure and, if so, to
identify the components responsible for the
photoprotective effects. Pretreatment of skin with
one such cosmetic product provided complete
protection against UV-induced erythema, sunburn
cell formation and Langerhans cell damage in
volunteers, skin types II and III, whose skin was
exposed to a 1.5 minimal erythema dose daily for 4
consecutive days. When individual components of
the cosmetic preparation were analyzed for their
photoprotective activities, it was found that both
the cinnamate and benzophenone sunscreen
combination and an extract of baker's yeast
present in the preparation had photoprotective
properties. These studies indicate that
incorporation of photoprotective agents into
cosmetic preparations provides a beneficial
function and should therefore be encouraged.
Experience with tretinoin therapy in
temperate regions.
Caputo R; Monti M; Rigoni C; Pinelli S; Motta
S; Barbareschi M
First Department of Dermatology and Paediatric
Dermatology, University of Milan, Italy.
Br J Dermatol (England) Sep 1992, 127 Suppl 41
p51-3
In a previously reported study on the
anti-photoageing effects of topical tretinoin, the
following regimen produced good patient
compliance: 0.01% for 1 month, 0.025% for 1 month;
and 0.05% for 4 months. The majority of patients
(60/89) enrolled in the initial study continued to
apply the cream to the face, and a further 140
patients were enrolled for a long-term study (mean
duration 2 years). The prolonged study showed that
91.4% of patients used tretinoin in an attempt to
slow down skin aging , and 8.6% sought subjective
skin benefits. Of the 163 patients who completed
the study, 58.8% sought an improvement of
wrinkles, 30.1% skin trophism and 14.7% reduced
pigmentation. The product was used throughout the
year by 66.9% of patients, but 8.0% stopped using
it during the summer. A daytime moisturizing cream
was required by 77.9% of patients, and 82.8% used
a sunscreen in the summer. Tretinoin was applied
to other areas of the body by 63.8% of
patients.
Facial
moisturizers and wrinkles.
Jackson EM
Dermatol Nurs (United States) Jun 1992, 4 (3)
p205-7
Facial moisturizers are part of the cosmetic
category known as skin care products, which also
includes other facial products such as
astringents, toners, soaps, and bath products.
This article describes the composition and
pharmaceutics of currently marketed moisturizers,
the use of fragrances and preservatives in these
products, how cosmetic facial moisturizers work on
wrinkles, sunscreen -containing facial
moisturizers, and the Food and Drug
Administration's record regulating drug claims for
anti-wrinkling products.
Sunscreens with low sun protection
factor inhibit ultraviolet B and A photoaging in
the skin of the hairless albino
mouse.
Harrison JA; Walker SL; Plastow SR; Batt MD;
Hawk JL; Young AR
Photobiology Unit, United Medical School of Guy's
Hospital, University of London, United Kingdom.
Photodermatol Photoimmunol Photomed (Denmark) Feb
1991, 8 (1) p12-20
We examined the chronic effect of long daily
suberythemal, fluorescent solar-stimulated
radiation (FSSR; ultraviolet B (UVB)+A(UVA)) and
UVA alone on female Skh-1 hairless albino mouse
skin. Mice were dorsally irradiated 8 h every
weekday for 16 weeks with FSSR or UVA, or 32 weeks
with UVA alone. Various topical, low
concentration, UVB and/or UVA sunscreens were
applied before irradiation. Damage was assessed by
skin-fold thickness, histology and biochemically
by changes in the proportion of type III collagen.
All FSSR-exposed mice showed increased skin
thickening, elastic fibre hyperplasia, collagen
damage and an increased proportion of type III
collagen. Application of the UVB sunscreen (2.00%)
resulted in marked protection for all
nonbiochemical endpoints. There was no obvious
advantage of adding 0.75% UVA sunscreen to the UVB
sunscreen , but adding 2.00% UVA sunscreen reduced
biochemical changes and connective tissue damage.
Sixteen weeks of UVA irradiation caused skin
thickening and laxity but the histology and
biochemistry were indistinguishable from the
controls. The mice irradiated with UVA for 32
weeks showed slight elastic fibre hyperplasia and
collagen damage histologically, and increased skin
thickening and laxity; these changes were
unmodified by the 0.75% UVA sunscreen. These mice
showed a significant increase in the proportion of
type III collagen against which the UVA sunscreen
offered protection. Our data suggest that UVA may
be important in photoaging and that the use of low
sun protection factor UVB+ UVA sunscreens on a
day-to-day basis may offer some protection from
solar photoaging.
Time-dependent decrease in sunscreen
protection against chronic photodamage in
UVB-irradiated hairless mouse skin.
Bissett DL; McBride JF; Hannon DP; Patrick
LF
Procter and Gamble Co., Miami Valley
Laboratories, Cincinnati, OH 45239-8707.
J Photochem Photobiol B (Switzerland) Jun 1991, 9
(3-4) p323-34
To determine the time dependence of sunscreen
protection against chronic photodamage in hairless
mice, the time was varied (0-8 h) between topical
sunscreen treatment and UVB radiation exposure.
Sunscreen products with labeled sun protection
factor (SPF) values of 2, 4 and 8 were evaluated;
these values were verified in a guinea pig model
for SPF determinations. When applied immediately
prior to UVB radiation exposure, these sunscreen
products were very effective in prevention of skin
wrinkling and tumor formation. Onset of
photodamage was delayed, the delay being greater
with higher SPF values. However, the sunscreen
actives were rapidly lost from the skin surface,
and their protective effect diminished strikingly
as the time between treatment and irradiation
increased. For daily protection against chronic
photodamage, this suggests a need for
photoprotectants with greater substantivity to
achieve a high level of protection throughout the
day.
Sunscreens and the prevention of skin
aging.
Lowe NJ
University of California, Los Angeles School of
Medicine.
J Dermatol Surg Oncol (United States) Oct 1990,
16 (10) p936-8
It has been well established in both human and
animal skin that ultraviolet radiation from both
ultraviolet B (UVB) (290 nm-320 nm) and
ultraviolet A (UVA) (320 nm-420 nm) can produce
profound changes in the skin that with recurrent
exposure, cause it to become what we recognize as
photoaged skin. Experimental studies in animals
have confirmed that some sunscreen chemicals are
capable of providing protection against
ultraviolet-induced photoaging. It is presumed
that regular use of these effective sunscreens
will also reduce skin aging changes in humans. (14
Refs.)
Photosensitivity in the
elderly.
Hawk JL
Photobiology Unit, St Thomas's Hospital, London,
U.K.
Br J Dermatol (England) Apr 1990, 122 Suppl 35
p29-36
Photosensitivity to drugs and chemicals in the
elderly is more prevalent due to more frequent use
of medications. Phototoxic reactions to common,
orally administered drugs such as diuretics,
cardiac agents and antidiabetics may occur and the
reactions may be remedied by discontinuing drug
therapy. Photocontact dermatitis due to the
ingredients in sunscreens or other agents, such as
perfumes, may also arise. Diagnosis is often
confirmed by photopatch testing and subsequent
avoidance of these agents leads to gradual
resolution. Idiopathic photodermatoses, such as
sunlight-induced polymorphic light eruption or
solar urticaria, may occur and persist from an
early age and, in elderly subjects, they can cause
mild to marked disability. The most disturbing
disorder of this type is the severe, widespread
eczematous chronic actinic dermatitis, which can
be difficult to diagnose. Porphyrias, such as
variegate porphyria or erythropoietic
protoporphyria, may persist from an early age,
whereas porphyria cutanea tarda generally begins
in later life. Porphyrias all have specific
clinical and biochemical features and, apart from
variegate porphyria, usually respond well to
treatment following diagnosis. Exposure of elderly
skin to sunlight may also cause deterioration of
many ordinary dermatoses, particularly seborrhoeic
eczema, which generally respond to protection from
UV exposure and to treatment of the underlying
abnormality. Progress in identifying the
underlying causes, the availability of
increasingly sophisticated diagnostic techniques,
and improvements in sunscreen preparations and
therapeutic medications will probably
significantly reduce abnormal photosensitivity in
the elderly in the near future. (44 Refs.)
Senescence and
sunscreens
Young AR
Institute of Dermatology, United Medical School
of Guy's Hospital, London, U.K.
Br J Dermatol (England) Apr 1990, 122 Suppl 35
p111-4
The most reliable way to reduce the chronic
effects of solar UV radiation is to limit
exposure. Animal data using hairless albino mice
suggest that the routine use of sunscreens, which
usually act as UVB (280-315 nm) filters, may
prevent or inhibit skin photocarcinogenesis and
photoageing in man. Conditions of chronic use of
sunscreens in human skin, however, are not
established but it is possible that, under some
circumstances, sunscreen use could enhance skin
cancer risk. The use of sunscreens may prevent or
inhibit both sun-induced cancers and photoageing,
but as yet there is no established method of
designating the efficacies of sunscreens for the
prevention of the chronic effects of solar UV
radiation. This is an important research
objective. (31 Refs.)
Drug
treatment of photoaged skin
Griffiths C.E.M.
Prof. C.E.M. Griffiths, Section of Dermatology,
Phase II, Hope Hospital, Eccles Old Road, Salford
M6 8HD United Kingdom
cgriffit@fs1.ho.man.ac.uk
Drugs and Aging (New Zealand) 1999, 14/4
(289-301)
Although the prevention of skin aging is a holy
grail of the cosmetic and pharmaceutical
industries, this venture may be misplaced. The
predominant clinical and biochemical features of
aged skin are mostly attributable to photoaging
rather than chronology. For instance chronic sun
exposure is the major determinant of age spots
(actinic lentigines) and wrinkles. Surgical
approaches to the treatment of photoaging include
face-lift, dermabrasion, chemical peeling,
collagen and botulinum toxin injections, and laser
re-surfacing. These approaches all have benefit
and improve the clinical features of facial
photoaging. Drug or pharmaceutical prevention and
treatment of photoaged skin is still in its
infancy. The main pharmaceutical approach to
prevention of photoaging lies in the assiduous use
of sunscreens. Recent evidence points to the
importance of ultraviolet A (UVA) radiation as
well as ultraviolet B (UVB) radiation in the
aetiology of photoaging and thus the need fur
sunscreens that block both UVB and UVA. Drug
treatment of photoaged skin can be categorised as
antioxidants, alpha-hydroxy acids and topical
retinoids. Of these 3 approaches only topical
retinoids, particularly tretinoin (all-trans
retinoic acid), have a well documented ability to
repair photoaged skin at the clinical,
histological and molecular level. Furthermore, the
use of topical retinoids may actually prevent
photoaging. The current interest in pharmaceutical
modulation of the photoaging process has attracted
considerable research into the mechanisms of
photoaging and cutaneous aging. It is likely that
treatment for, or prevention of, the chronological
aging process may result from such research.
Molecular mechanisms of cutaneous
aging: Connective tissue alterations in the
dermis
Uitto J.; Bernstein E.F.
Dr. J. Uitto, Dept. of Dermatol./Cutaneous
Biolgy, Jefferson Medical College, Bluemle Life
Sciences Building, 233 S. 10th Street,
Philadelphia, PA 19107-5541 United States
Journal of Investigative Dermatology Symposium
Proceedings (United States) 1998, 3/1 (41-44)
Cutaneous aging is a complex biological
phenomenon consisting of two distinct components,
(a) the intrinsic, genetically determined
degenerative aging processes and (b) extrinsic
aging due to exposure to the environment, also
known as 'photoaging'. These two processes are
superimposed in the sun- exposed areas of skin,
with profound effects on the biology of cellular
and structural elements of the skin. This overview
summarizes our current understanding of the
mechanisms of innate versus extrinsic aging with
emphasis on connective tissue alterations,
primarily collagen and the elastic fiber network.
We also introduce a novel transgenic mouse model,
expressing a human elastin promoter-reporter gene
construct, suitable for studies on biology and
preventive pharmacology of the cutaneous
aging.
The
role of cosmetology and the aesthetic within
dermatology in Spain
Torras H.
H. Torras, Servei Dermatologia, Hospital Clinic
Provincial, Villarroel 170, 08036 Barcelone
Spain
Nouvelles Dermatologiques (France) 1998, 17/4
(249-252)
Cosmetology is the science of art of treating
and improving the appearance of healthy skin. It
is almost as old as humanity. Until a few years
ago, dermatology was only concerned with skin
pathology. Cosmetology was mostly chemical, it was
concerned with the formulation of products for
modifying an aesthetic defect or improving the
appearance of ski. At that time, communication
between dermatology and Cosmetics was quite
limited. Today, 'Cosmetic dermatology' is
concerned with skin problems that are expression
of a skin dysfunction. So who must take care of
skin aging caused by the sun protection or
seborrheic or dry skin? The logical answer is the
dermatologist. During the last 20 years, the
number of dermatologists in Spain has doubled, and
this is one of the reasons for the increase in
cosmetic dermatology prescriptions. In 1973,
'cosmeceuticals' for the skin represented 30% of
total OTC products. In 1993 this percentage rose
to 64.7% or more than double. The recent evolution
of Cosmetic dermatology and the growing interest
shown by dermatologists are demonstrated by
several facts: - they often prescribe skin care
for normal skin, which was rare 20 years ago; -
they make a more precise evaluation of skin type;
- they are more interested in Cosmetics and skin
aging treatments; - there are more prescriptions
for 'cosmeceutical lines'. In the future,
socioeconomic progress shall increase the
development of new products. European countries
will show a progressive increase in
homogenization, but certain national differences,
specific to the culture of each country or region,
will remain.
The
study on the ultraviolet-B blocking effect of
sunscreens in the epidermal Langerhans cells of
hairless mice
Won Y.H.; Yoo Y.E.; Lee S.C.; Kim Y.P.; Chun
I.K.
Department Dermatology, Chonnam University
Medical School,Kwangju 501-757 South Korea
Annals of Dermatology (South Korea) 1995, 7/4
(288-294)
Background: Sunscreens have been used widely to
prevent the photosensitive skin diseases, skin
cancer, and skin aging . However, no sunscreen
blocks all kinds of effects caused by ultraviolet
light(UVL), and the effect of sunscreens on the
impairment of immune function by UVL irradiation
is controversial. Objective: We try to evaluate
the efficiency of sunscreens for blocking the
depletion of LC induced by UVB irradiation.
Method: The ATPase positive LCs were observed in
the skin of hairless mice(Hr+/Kud) irradiated by
UVB with or without topical application of
sunscreens. Two commercially available sunscreens
with respective SPF 8 and SPF 30 were applied to
the dorsal trunk skin. The mice were irradiated
with different increasing doses of UVB at a single
time. Results: The ATPase positive LCs in the
irradiated dorsal and ear skin were significantly
decreased in densities according to the dosage,
and apparently revealed a loss of their dendrites,
granulation, and clumping from a UVB dose of more
than 60mJ/Cmsup 2. With both sunscreen treatment
on the dorsal trunk before irradiation, the
densities of LCs on the dorsal skin were
significantly higher compared to the untreated
groups at all ranges of UVB doses in spite of a
dose dependent decrease in their density. However
there was no significant difference on their
preventive effect between both sunscreens(SPF 8
and SPF 30) except at high UVB doses of more than
240 mJ/Cmsup 2. Conclusion: The LC depletion
induced by UVB can be partially protected through
the topical application of a sunscreen at a UVB
dose dependent fashion. However SPF(sun protective
factor) dose not appear to be a good indicator for
evaluating sunscreens immunologically.
Awarness tophotodamage versus the
actual use of sun protection methods by young
adults
Harth Y.; Schemer A.; Friedman-Birnbaum R.
Department of Dermatology, Rambam Med. Cter.,
Faculty Med.,Haifa 31096 Israel
Journal of the European Academy of Dermatology
and Venereology (Netherlands) 1995, 4/3
(260-266)
Objective. There is accumulating evidence that
in spite of the large campaigns against excessive
solar exposure undertaken by dermatologists
worldwide, children and adolescents are still
spending long periods in the sun, and do not
follow the recommended sun protection guidelines.
The purpose of the present study was to evaluate
sun exposure in a group of young Israeli adults
and to compare it to their knowledge and
application of the various sun protection methods.
Methods. 202 Caucasian volunteers, (mean age 21.4
+/- 2.6), filled out detailed questionnaires on
their sun exposure and sun protection habits.
Results. More than 80% of our study participants
are regularly sun exposed for longer than 2 h per
day whereas sunscreens are utilized only by 64.9%.
Sunscreen use was significantly more prevalent in
females than males (81.3% vs. 46.5%). The majority
of sunscreen users and nonusers believed that
sunscreen could prevent skin cancer (94.3% and
82.0%, respectively) and that these compounds can
slow skin aging (90.8% and 76.4% respectively).
The understanding of the meaning of the 'SPF' was
significantly higher in the sunscreen users (85%)
than in the nonusers (62.0%). The majority of
sunscreen users utilized less than 150 ml of the
compound per year which is probably an inadequate
amount for a year for full body protection. The
two most common reasons for-not using sunscreens
regularly; were that the application is time
consuming, and that sunscreens prevent tanning.
Conclusion. Our data reveals a discrepancy between
a considerably good understanding of the need for
sun protection and the still deficient application
of these measures especially in young adult
males.
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