Different skin manifestations whether benign or
malignant may result from physical injuries to the skin. Melanomas
and other malignant tumors occur mainly in older age groups.
Actinic injury: The different clinical
manifestations of actinic injury are:
Photo-allergic dermatitis
Photo-toxic dermatitis
Chronic actinic dermatitis
Sunburn
Polymorphous light eruption
Freckles
Xeroderma pigmentosum
Colloid milium
Hydroa vacciniforme
Radio dermatitis
Neonatal cold injury
Skin tumors mainly melanomas.
SKIN AND SUN
The incidence of sunlight that can induce skin
tanning and photo damage has been increased in the past few years.
Children and susceptible individuals especially those with light
colored complexion of the skin are more susceptible to the harmful
effect of sun.
Serious and even fatal problems due to melanoma
and non-melanoma skin cancer do occur due to unwise excess exposure
to sunlight. That is “a hazardous
effort for a trivial cosmetic bronzing reward“.
SOLAR RADIATION
The radiation striking the earth is either
visible or invisible light. The harmful effect of the light spectrum
is the UV radiation. Ultra violet is of two types; UVA (10 per
cent), where it‘s intensity declines
from the noontime and UVB which constitutes (90 per cent) of the UV
reaching the ground.
Solar radiation includes the electromagnetic
spectrum, which begins from the short, high energy cosmic, gamma and
x-ray to the longer energy ultraviolet (UV), visible, infrared (IR),
microwave and radio waves. Most of the harmful solar radiation is
absorbed high in the atmosphere by the ozone at around 20 kilometers
above the sea level.
Factors affecting skin reaction
Skin reaction due to the effect of sunlight
depends on different factors mainly:
-
Age - Children are more susceptible
due to their delicate skin.
-
Type of skin - Blond and patients
with white skin and blue eyes are more susceptible than Asians and
Negroes. The dark skin has more defense mechanisms to the effect
of sunlight. This is due to the increased number and activity of
melanosomes in individuals with the dark skin.
-
Time of exposure - the harmful effect
of UVA :is more during the noontime (from 10a.m -4 p.m.).
The effects of UVA decrease by four o‘clock
in the afternoon. This is due to most of the rays are burnt at
that time and there is little in the atmosphere. UVB Effect :is
almost allover the day light.
-
Place of exposure - Exposure on the
seashores has more effect due to reflection of UVR by water and
sand. Snow also reflects UVR and this why the effect is more on
snowy mountains.
-
Duration of exposure: The effect is
more with increased time of exposure especially in those who are
not accustomed to expose their skin to direct sun light such as
infants and children.
Immunologic factors
Immunologic factors have an important role.
Patients who have photosensitivity will have a direct effect on the
sun-exposed areas and may involve also covered areas of the body.
Drugs
Systemic drugs:
The effect of solar radiation is more severe with
patients who are receiving medications causing photosensitization
such as Tetracycline or Phenothiazines.
Topical preparations:
Topical Psoralenes, plants containing
Furocoumarines, perfumes and cosmetic preparations may act as
photosensitizers causing photodermatitis.
Clinical manifestation of effect of sunlight.
A. Acute solar reaction.
Sunburn
Erythema is the immediate response that may be
mild or severe. Vesiculo bullous eruption appears later on the
exposed areas with severe burning sensation and oozing of the skin
surface. The reaction may be a burn of the first or second degree.
The severity of erythema depends on different
factors mainly the skin color where it is more in blond and white
races. Melanin in the dark skinned individuals acts as a protective
screen from the effect of sunlight, where it reflects, absorbs and
scatters ultraviolet radiation.
Fig. 338. Sun burn |
Fig. 339. Freckles |
The type of reaction due to sun exposure is an
immediate erythema, photodermatitis or sunburn due to UVA or delayed
erythema, which begins after few hours from exposure to UVB
radiation. UVB has an effect on the exposed and covered parts of the
body on contrast to UVA that has its effect on the sun exposed
areas. This reaction may resolves after few days leaving skin
tanning. Tanning occurs as a result of increased production of
melanin in the melanocytes in response to UVB, which increases the
binding of the circulating melanocyte stimulating hormone to the
melanocytes leading to melanocyte proliferation,
Dendritic arborization leading to skin tanning.
B. Photo toxic reaction
C. Photo allergic reaction
D. Polymorphous light eruption
E. Chronic effect of sun exposure
Chronic solar effect
Skin tanning
and thickening of the stratum corneum are the mildest hazard from
chronic exposure to sunlight. Solar keratoses, melanomas and skin
squamous carcinoma are very serious complication where fatal cases
from melanomas are much increased during the past few years due
to excess sun exposure especially on the sea shores to get tanned
skin. Wrinkles and premature skin aging due to collagen degeneration
from the effect of sun light.
Fig. 340. Squamous cell carcinoma |
Photodynamic and phototoxic reactions.
Drugs and other chemicals with photodynamic and
phototoxic activity potentiate the pigmentogenic effect of UV lights
causing photodermatitis. Tanning follows the sunburn-like reactions
to certain drugs such as that of tetracycline, but not photoallergic
reactions.
Fig. 341. Polymorphous light Eruption |
Fig. 342. Phtodermatitis |
If the photodynamic agent is applied directly to
the skin the intensity of the pigmentary response is greatly
enhanced and the hypermelanosis may be heavy and persistent.
Phytophotodermatitis
Phytophotodermatitis is an inflammatory and
pigmentary reaction of the skin due to the effect of sunlight,
predisposed by contact with furocoumarins in plants or other
compounds.
The reaction occurs in the areas exposed to
sunlight after these plants have been crushed on the skin surface.
There is some individual variation in
susceptibility, but with adequate exposure most will react. If the
inflammatory phase is severe, bullae are formed, but in milder cases
only the pigmentary changes are conspicuous and follow the irregular
pattern of the points of contact of the plant stems and leaves with
the uncovered skin.
The most
common clinical syndrome is therefore a
bizarre network of pigmented streaks, often on the legs and
frequently in a child.
BERLOQUE DERMATITIS
Berloque dermatitis results from the potentiation
of the stimulation of melanogenesis by light by 5-methoxypsoralen or
bergamot oil contained in perfumes, notably eau-de-Cologne.
Wavelengths of light above 320 nm are involved.
There is wide individual variation in susceptibility and the
reaction occurs in only a small proportion of those exposed to the
effect of sun.
Abraded or macerated skin surface is more
susceptible to the harmful effect of sun.
Hot, humid conditions favor absorption.
|
Fig. 343. Berloque dermatitis
|
The pigmentation occurs in susceptible subjects
who have been exposed to light after the application of perfume. The
distribution of the lesions is therefore variable but their
configuration is usually distinctive.
Deep-brown pigmentation follows the pattern
formed by the droplets of perfume over the skin from their points of
application. The pigmentation fades after weeks or months. The
condition is now much less frequent, though it is a continuing
cosmetic problem.
Topical photosensitizers.
Following the application of Psoralenes to the
skin and irradiation with long-wave UV light. There is an increase
in the number of functional melanocytes. These cells are more
dendritic and more dopa-positive. There is an increase in
melanogenesis and the distribution pattern of the melanosomes in the
keratinocytes is changed from the aggregated to the non-aggregated
form.
The bronze pigmentation gradually fades after
discontinuation of phototherapy.
|
Fig. 344a. Phtotoxic reaction
(Trisoralene & PUVA)
|
The hazardous effect of sun light exposure is
more serious in infants and young age groups. Recorded deaths have
been reported in several affected neonates, either from kernicterus
or from extra hepatic biliary duct atresia.
Phototherapy
Phototherapy with blue light at 420-460 nm leads
to the trans cutaneous photo-oxidation of bilirubin, and has become
firmly established as a safe and effective treatment for neonatal.
A number of minor cutaneous side effects have had
been described.
Some babies develop a macular erythematous rash.
Darkening of treated areas of skin lasting for
several months has been reported in racially black babies.
Fig.344b.
Dermatitis & scarring
due to physical injuries (Burn)
|
“Bronze baby“
syndrome
This is a rare complication of neonatal
phototherapy in which a dark brown (‘bronze‘)
pigmentation of the skin, serum and urine follows phototherapy, and
remains as the hyper bilirubinaemia fades.
Hepatic disease appears to be a prerequisite for
the development of this complication.
The bronze pigmentation gradually fades after
discontinuation of phototherapy, but death has been reported in
several affected neonates, either from kernicterus or from extra
hepatic biliary duct atresia.
METHODS OF PROTECTION FROM THE EFFECT OF SUN
The harmful effects of sun are strongest between
10 a.m. and 4 p.m.
-
Use a broad-spectrum sunscreen with a Sun
Protection Factor.
-
Re-apply
sunscreen every 2 hours when
outdoors, even in cloudy days especially when in seashores and snowy areas.
-
Wear protective , tightly woven clothing ,
such as long sleeved shirts and pants .
-
Wear a wide-brimmed hat and sunglasses when
outdoors.
-
Stay in the shade whenever possible. If your
shadow is shorter than you are, you are likely more exposed to sun
damage.
-
Avoid reflecting surfaces.
-
Children are more sensitive to the effect of
sun.
-
Minimize sun exposure.
-
Avoid tanning beds.
-
Avoid photosensitizers whether drugs or
certain plants and trees.
SUN SCREENS
Sunscreens are UV-absorber that contain certain
ingredients such as p-amino benzoic acid esters, methyl-, phenyl-
and benzyl salicylates, benzyl cinnamate, digalloyl trioleate
(photosensitizer), 4-isopropyl-dibenzoylmethane,
3-(4-methylbenzylidene)-camphor and
4-tertiarybutyl-4'-methoxy-dibenzoylmethane.
Sunscreens were presented in the market in 1928
as an emulsion of benzyl salicylic acid and benzyl cinnamate and
later other sunscreens were available as quinine bisulfate and
quinine oleate. Sun block usually reflects or scatters all UV rays.
This should be applied about 20 minutes before exposure to sun and
should be reapplied after two hours. It should be noted that
children and other sensitive groups should be instructed to use
sunscreens routinely, like brushing their teeth.
Sunscreens of at least 15 SPF lip preparation is
available and should be used to protect the lips from actinic
injury.
Eye protection from the effect of UV by using
special sunglasses, which have the ability to block UVA and UVB wide
brim hats can also have some protection.
All skin types of different age groups especially
infants and children need protection from solar UV. Those with Type
I and Type II with blond and light skin color are more susceptible.
Broad-spectrum sunscreens with an SPF of at least 15 offer
substantial protection against sun burning, especially for
fair-skinned people.
It is very important to minimize exposure from 10
AM to 4 PM and try to be in the shade. Shade can‘t
give complete protection from the effect of sun, since sand, water,
snow and grass reflect UV rays even if the body is in a shady area.
Umbrella used outdoors, on the seashores or personal one can give
some protection . The most effective protection in all cases is the
broad-spectrum sun block.
Para-amino benzoic acid and its derivative is a
popular sunscreen agent.
Sunscreens containing p-amino benzoic acid
esters, methyl-, phenyl- and benzyl salicylates, benzyl cinnamate,
digalloyl trioleate, (photosensitizer) are used as sunscreens.
It should be noted that some sunscreens may cause
photosensitization. It is important to select the effective and
non-sensitizing type of sunscreen.
Topical
Sunscreen agents
-
Total
block (Louis med)
-
Presun
- Coppertone Kids Sunblock
- DuraScreen
- Eclipse Lip & Face Protectant
- Eclipse Original Sunscreen
- Eucerin Dry Skin Care Daily Facial
- Formula 405 Solar
- Hawaiian Baby Faces Sunblock
- Johnson's Baby Sunblock Extra Protection
- Johnson's Baby Sunblock
- Johnson's No More Tears Baby Sunblock
- Maxafil Cream
- Mentholatum Lip Balm
- Neutrogena Chemical-Free Sunblocker
- Neutrogena Deep Glow
- Neutrogena Intensified Day Moisture
- Neutrogena Light Glow
- Neutrogena Lip Moisturizer
- Neutrogena Moisture Untinted & with Sheer Tint
- Neutrogena No Stick Sunscreen
- Neutrogena Sunblock
- Nivea Sun
- Noxzema Moisturizer
- Oil of Olay Daily UV Protectant Beauty Fluid
- Oil of Olay Daily UV Protectant
- Oil of Olay Moisture Replenishment
- PreSun Active Clear
- Aminobenzoic Acid, Padimate O, and Oxybenzone combination
- Aminobenzoic Acid and Titanium Dioxide combination
- Aquaderm Sunscreen Moisturizer
- Aquaray Sunscreen
- Bain de Soleil All Day For Kids
- Bain de Soleil All Day Sunfilter
- Bain de Soleil Mega Tan
(WEB MED)
N.B.
: More details can be found in chapter 05 " Dermatological
treatment"
Precautions
Allergic reaction : sensitization to the active ingredient or the
base of the sunscreen product may occur especially in patients
having a history of an allergic reaction to drugs such as”
caine” group such as benzocaine, anesthetics artificial sweetening
agent such as saccharine, antidiabetics, analine dyes, sulfa ,
diuretics such as thiazides, perfumes , tooth paste, preservatives
and others.--
.
Skin Type (complexion)
|
Appropriate
Sunscreen Agent
|
Very
fair--Always burns easily; rarely tans
|
Use
SPF 20 to 30
|
Fair--Always
burns easily; tans minimally
|
Use
SPF 12 to 20
|
Light--Burns
moderately; tans gradually (light brown)
|
Use
SPF 8 to 12
|
Medium--Burns
minimally; always tans well (moderate brown)
|
Use
SPF 4 to 8
|
Dark--Rarely
burns; tans profusely (dark brown)
|
Use
SPF 2 to 4
|
- Pregnancy--Studies on effects in
pregnancy have not been done in either humans or animals.
- Breast-feeding--Sunscreen
agents have not been reported to cause problems in nursing babies.
- Children--Infants under 6 months of age
should be kept out of the sun. Sunscreen agents should not be
used on infants under 6 months of age because of increased chance of
side effects
- Age --Do not use
sunscreen agents on infants less than 6 months of age. For
children 6 months of age and older, use a lotion form of
sunscreen with SPF of 15 or higher. Avoid
using alcohol-based sunscreen products for this age group.
- Site of application
--For
the ear and nose, use a physical sunscreen agent. For the lips,
use a gel-based lip sunscreen or lip balm.
- Skin condition
--If your
skin is dry, use a cream or lotion form of sunscreen agent. If
your skin is oily, use an alcohol or gel-based sunscreen. Avoid
using alcohol-based sunscreens on eczematous or inflamed skin.
Before every exposure to the sun, apply an appropriate sunscreen
product that protects you against ultraviolet sun rays. For maximum
sun protection, sunscreens should be applied uniformly and thickly
to all exposed skin surfaces (including the lips, using lip
sunscreen or lip balm). Sunscreen products containing aminobenzoic
acid, lisadimate, padimate O, or roxadimate should be applied 1 to 2
hours before sun exposure. Other sunscreen products should be
applied 30 minutes before sun exposure, unless otherwise directed by
the package instructions. Lip sunscreens should be applied 45 to 60
minutes before sun exposure.
Because most sunscreens are easily removed from the skin, you
should reapply these products liberally every 1 to 2 hours for
adequate protection. You should reapply sunscreen especially after
swimming or heavy perspiration. Lip sunscreens should be reapplied
liberally at least once every hour while you are in the sun and also
before and after swimming, after eating and drinking, and during
other activities that remove it from the lips.
- Keep sunscreen products away from the
eyes .
Some sunscreen agents contain alcohol and are flammable. Do
not use near heat, near open flame, or while smoking .
- Dosing--Follow your
doctor's orders or the directions on the label . The following
information includes only the average dose of sunscreen agents.For topical dosage forms (cream, gel, lotion, lip balm, oil,
spray, and stick):
- For
sunburn (prevention):
- Adults
and children 6 months of age and older--Apply liberally and
evenly to exposed area(s) of skin (including the lips, using
lip sunscreen or lip balm) before sun exposure. Reapply when
needed.
- Children
under 6 months of age--Use is not recommended.
( webmed)
REFERENCES
-
Kligman AM. Early destructive effects of
sunlight on human skin. J Am Acad Dermatol 1969; 210: 2377-80.
-
Kumakiri M, Hashimoto K, Willis I. Biologic
changes due to longwave ultraviolet radiation in human skin. J
InvestDermatol 1977; 69: 392-400.
-
Mitchell RE. Chronic solar dermatosis: a light
and electron microscopic study of the dermis. J Invest Dermatol
1967; 48:203-20.
-
Sams WM. Sun induced aging. In: Gilchrest BA,
ed. The Aging Skin. Philadelphia: WB Saunders. Dermatologic
Clinics1986; 4: 509-16.
-
Fitzpatrick TB. The validity and practicality
of sun-reaction skin types I through VI. Arch Dermatol 1988; 124:
869-71.
-
Johnson BE. Changes in sunburn and mechanisms
of protection. J Soc Cosm Chem 1978; 23: 31.
-
Pathak MA. Sunscreens: topical and systemic
approaches for protection against harmful effects of solar
radiation. J AmAcad Dermatol 1982; 7: 285-312.
-
Pfau RG, Hood AF, Morison WL. Photo-ageing;
the role of UVB, simulated UVB and PUVA. Br J Dermatol 1986;
114:319-27.
-
Sams WM. Sun induced aging. In: Gilchrest BA,
ed. The Aging Skin. Philadelphia: WB Saunders. Dermatologic
Clinics1986; 4: 509-16.
-
Gilchrest BA, Blog FB, Szabo G. Effect of
aging and chronic sun exposure on melanocytes in human skin. J
InvestDermatol 1979; 73: 141-3.
-
Findlay GH, Hull PR. Eruptive tumours on
sun-exposed skin after benoxaprofen. Lancet 1982; ii: 95.
-
Roelandts R, van Hee J, Bonamie A et al. A
survey of ultraviolet absorbers in commercially available sun
products. Int JDermatol 1983; 22: 247-55.
-
Thune P, Eeg-Larsen T. Contact and
photocontact allergy in persistent light reactivity. Contact Derm
1984; 11: 98-107.
-
Thune P. Basic mechanisms of
photosensitization. In: Frosch PJ, Dooms-Goossens A, LaChappelle LM
et al., eds. CurrentTopics in Contact Dermatitis. Berlin:
Springer-Verlag, 1989: 473-9.
-
Thompson G, Maibach H, Epstein J. Allergic
contact dermatitis from sunscreen preparations complicating
photodermatitis.Arch Dermatol 1977; 113: 1252-3.
-
Ramsay CA. Skin responses to ultraviolet
radiation in contact photodermatitis due to Fentichlor. J Invest
Dermatol 1979;72: 99-102.
-
Kopf AW, Kripke ML, Stern RS. Sun and
malignant melanoma. J Am Acad Dermatol 1984; 11: 674-84.
-
Zaynoun ST, Johnson BE, Frain-Bell W. A study
of oil of bergamot and its importance as a phototoxic agent: II.
Factorswhich affect the phototoxic reaction induced by bergamot oil
and psoralen derivatives. Contact Derm 1977; 3: 225-39.
-
Willis I, Kligman AM. The mechanism of
photoallergic contact dermatitis. J Invest Dermatol 1968; 51:
378-84.
Top
|