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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


Polymorphous light eruption


Xeroderma pigmentosum

Colloid milium

Hydroa vacciniforme

Radio dermatitis

Neonatal cold injury

Skin tumors mainly melanomas.



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“.



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:

  1. Age - Children are more susceptible due to their delicate skin.

  2. 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.

  3. 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.

  4. 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.

  5. 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.


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.


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 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 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 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.



The harmful effects of sun are strongest between 10 a.m. and 4 p.m.

  1. Use a broad-spectrum sunscreen with a Sun Protection Factor.

  2. Re-apply sunscreen every 2 hours when outdoors, even in cloudy days especially when in seashores and snowy areas.

  3. Wear protective , tightly woven clothing , such as long sleeved shirts and pants .

  4. Wear a wide-brimmed hat and sunglasses when outdoors.

  5. Stay in the shade whenever possible. If your shadow is shorter than you are, you are likely  more exposed to sun damage.

  6. Avoid reflecting surfaces.

  7. Children are more sensitive to the effect of sun.

  8. Minimize sun exposure.

  9. Avoid tanning beds.

  10. Avoid photosensitizers whether drugs or certain plants and trees.



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
    • Lotion 
  • Aminobenzoic Acid and Titanium Dioxide combination
    • Cream
  • Aquaderm Sunscreen Moisturizer 
  • Aquaray Sunscreen
  • Bain de Soleil All Day For Kids
  • Bain de Soleil All Day Sunfilter 
  • Bain de Soleil Mega Tan 


  N.B. : More details can be found in chapter 05 " Dermatological treatment"


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)

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)



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  2. Kumakiri M, Hashimoto K, Willis I. Biologic changes due to longwave ultraviolet radiation in human skin. J InvestDermatol 1977; 69: 392-400.

  3. Mitchell RE. Chronic solar dermatosis: a light and electron microscopic study of the dermis. J Invest Dermatol 1967; 48:203-20.

  4. Sams WM. Sun induced aging. In: Gilchrest BA, ed. The Aging Skin. Philadelphia: WB Saunders. Dermatologic Clinics1986; 4: 509-16.

  5. Fitzpatrick TB. The validity and practicality of sun-reaction skin types I through VI. Arch Dermatol 1988; 124: 869-71.

  6. Johnson BE. Changes in sunburn and mechanisms of protection. J Soc Cosm Chem 1978; 23: 31.

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  8. Pfau RG, Hood AF, Morison WL. Photo-ageing; the role of UVB, simulated UVB and PUVA. Br J Dermatol 1986; 114:319-27.

  9. Sams WM. Sun induced aging. In: Gilchrest BA, ed. The Aging Skin. Philadelphia: WB Saunders. Dermatologic Clinics1986; 4: 509-16.

  10. Gilchrest BA, Blog FB, Szabo G. Effect of aging and chronic sun exposure on melanocytes in human skin. J InvestDermatol 1979; 73: 141-3.

  11. Findlay GH, Hull PR. Eruptive tumours on sun-exposed skin after benoxaprofen. Lancet 1982; ii: 95.

  12. 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.

  13. Thune P, Eeg-Larsen T. Contact and photocontact allergy in persistent light reactivity. Contact Derm 1984; 11: 98-107.

  14. 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.

  15. Thompson G, Maibach H, Epstein J. Allergic contact dermatitis from sunscreen preparations complicating photodermatitis.Arch Dermatol 1977; 113: 1252-3.

  16. Ramsay CA. Skin responses to ultraviolet radiation in contact photodermatitis due to Fentichlor. J Invest Dermatol 1979;72: 99-102.

  17. Kopf AW, Kripke ML, Stern RS. Sun and malignant melanoma. J Am Acad Dermatol 1984; 11: 674-84.

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