ultraviolet therapy ultraviolet radiation (uvr) in electromagnetic spectrum uvr ranges from 2000 to...
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Ultraviolet TherapyUltraviolet TherapyUltraviolet TherapyUltraviolet Therapy
Ultraviolet Radiation(UVR)
Ultraviolet Radiation(UVR)
• In electromagnetic spectrum UVR ranges from 2000 to 4000 Å
• Divided into three ranges: – UV-A- near UV- 3200 to 4000 Å
• Little or no physiologic effect
– UV-B- middle UV- 2900 to 3200 Å • Associated with sunburn and age-related skin
changes
– UV-C- far UV- 2000 to 2900 Å• Bactericidal
• In electromagnetic spectrum UVR ranges from 2000 to 4000 Å
• Divided into three ranges: – UV-A- near UV- 3200 to 4000 Å
• Little or no physiologic effect
– UV-B- middle UV- 2900 to 3200 Å • Associated with sunburn and age-related skin
changes
– UV-C- far UV- 2000 to 2900 Å• Bactericidal
Ultraviolet RadiationUltraviolet Radiation
• UVR apparatus most likely to be used would generate UVR in UV-B, UV-C or both ranges
• UVR is absorbed within first 1 to 2 mm of human skin
• Most of physiologic effects are superficial
• Used to treat various skin disorders
• UVR apparatus most likely to be used would generate UVR in UV-B, UV-C or both ranges
• UVR is absorbed within first 1 to 2 mm of human skin
• Most of physiologic effects are superficial
• Used to treat various skin disorders
Effect On CellsEffect On Cells
• Exposure of skin to UVR causes chemical excitation of cells which leads to physiologic changes within these cells
• Alteration of cell biochemistry and cellular metabolism which affects synthesis of DNA and RNA
• This leads to alterations in protein and enzyme production
• Exposure of skin to UVR causes chemical excitation of cells which leads to physiologic changes within these cells
• Alteration of cell biochemistry and cellular metabolism which affects synthesis of DNA and RNA
• This leads to alterations in protein and enzyme production
Short-Term Effects on SkinShort-Term Effects on Skin• Skin consists of two
layers– Epidermis
• Contains keratinocytes which produce keratin,- fibrous protective protein of skin
– Dermis • Papillary layer - rich blood
supply• Reticular layer - heavy
connective tissue containing fibroblasts, histocytes, and mast cells
• Skin consists of two layers– Epidermis
• Contains keratinocytes which produce keratin,- fibrous protective protein of skin
– Dermis • Papillary layer - rich blood
supply• Reticular layer - heavy
connective tissue containing fibroblasts, histocytes, and mast cells
ErythemaErythema
• Generalized response to UVR exposure culminates in development of an acute inflammatory reaction
• End results of active inflammation are – Erythema - reddening of skin associated
with sunburn– Pigmentation -tanning– Increased epidermal thickness
• Generalized response to UVR exposure culminates in development of an acute inflammatory reaction
• End results of active inflammation are – Erythema - reddening of skin associated
with sunburn– Pigmentation -tanning– Increased epidermal thickness
InflammationInflammation
• Inflammatory response characterized by local vasodilation and increased capillary permeability causing erythema
• Permits certain proteins to move from capillaries into dermis resulting in a change in osmotic pressure
• Water drawn into area and edema occurs
• Phagocytic cells eliminate dead cells
• Inflammatory response characterized by local vasodilation and increased capillary permeability causing erythema
• Permits certain proteins to move from capillaries into dermis resulting in a change in osmotic pressure
• Water drawn into area and edema occurs
• Phagocytic cells eliminate dead cells
PhotosensitizationPhotosensitization
• Over sensitization to UVR as a result of excitation of a chemical by UVR exposure
• Acute effects of UVR exposure can be exacerbated if certain chemicals or medications are present on skin or in body
• Over sensitization to UVR as a result of excitation of a chemical by UVR exposure
• Acute effects of UVR exposure can be exacerbated if certain chemicals or medications are present on skin or in body
TanningTanning• Increase of pigmentation in skin • Protective mechanism activated by UVR
exposure• Increase of melanin (pigment responsible
for darkening) within skin causes tan – Functions as a biologic filter of UVR
• By scattering radiation • By absorbing UVR• By dissipating absorbed energy as heat
• Increase of pigmentation in skin • Protective mechanism activated by UVR
exposure• Increase of melanin (pigment responsible
for darkening) within skin causes tan – Functions as a biologic filter of UVR
• By scattering radiation • By absorbing UVR• By dissipating absorbed energy as heat
TanningTanning
• Immediate tanning occurs following UVR exposure– Appears most often in darkly
pigmented individuals– Represents the darkening of
melanosomes already present in the skin
– Begins to fade 1 hour after exposure and is hardly noticeable 3 to 8 hours
• Immediate tanning occurs following UVR exposure– Appears most often in darkly
pigmented individuals– Represents the darkening of
melanosomes already present in the skin
– Begins to fade 1 hour after exposure and is hardly noticeable 3 to 8 hours
TanningTanning
• Delayed tanning results from formation of new pigment (melanin) through melanogenesis – Delayed tanning usually becomes
apparent 72 hours after UVR exposure
• Delayed tanning results from formation of new pigment (melanin) through melanogenesis – Delayed tanning usually becomes
apparent 72 hours after UVR exposure
Artificial Tanning DevicesArtificial Tanning Devices
• Manufacturers claim tanning beds produce only UVR in UV-A spectrum and are safe – Production of this type of UV-A generator
is largely unregulated – Effects of long-term exposure to UV-A
are unknown – Caution should be exercised before using
an artificial source to expose to UVR
• Manufacturers claim tanning beds produce only UVR in UV-A spectrum and are safe – Production of this type of UV-A generator
is largely unregulated – Effects of long-term exposure to UV-A
are unknown – Caution should be exercised before using
an artificial source to expose to UVR
Long-Term Effects on SkinLong-Term Effects on Skin
• Premature aging of the skin – Dryness, cracking, and a decrease in
elasticity of skin resulting from epidermal solar elastosis • Alteration in the skin's elastic fibers • Linked to UVR-induced DNA damage
• Premature aging of the skin – Dryness, cracking, and a decrease in
elasticity of skin resulting from epidermal solar elastosis • Alteration in the skin's elastic fibers • Linked to UVR-induced DNA damage
Long-Term Effects on SkinLong-Term Effects on Skin• Skin cancer
– Most common malignant tumor found in humans
– Damage to DNA suspected as cause – Major types of skin cancer
• Basal cell carcinoma( rarely metastasizes) • Squamous cell carcinoma (metastasizes in 5%) • Malignant melanoma (Usually metastasizes
– Rate of cure exceeds 95% with early detection
• Skin cancer – Most common malignant tumor found in
humans – Damage to DNA suspected as cause – Major types of skin cancer
• Basal cell carcinoma( rarely metastasizes) • Squamous cell carcinoma (metastasizes in 5%) • Malignant melanoma (Usually metastasizes
– Rate of cure exceeds 95% with early detection
SunscreensSunscreens
• Sunscreen’s effectiveness in absorbing sunburn inducing radiation is expressed as sun protection factor (SPF)
• SPF of 6 indicates you can be exposed to UVR six times longer than without a sunscreen before receiving a minimal erythemal dose
• Sunscreen’s effectiveness in absorbing sunburn inducing radiation is expressed as sun protection factor (SPF)
• SPF of 6 indicates you can be exposed to UVR six times longer than without a sunscreen before receiving a minimal erythemal dose
Effect On EyesEffect On Eyes• UVR exposure of the eyes causes an acute
inflammation called photokeratitis– Delayed reaction occurring within 6 to 24 hours– Conjunctivitis develops, accompanied by
erythema of adjacent facial skin – Sensation of a foreign body on eye – Photophobia– Increased tear production– Spasm of the ocular muscles
• UVR exposure of the eyes causes an acute inflammation called photokeratitis– Delayed reaction occurring within 6 to 24 hours– Conjunctivitis develops, accompanied by
erythema of adjacent facial skin – Sensation of a foreign body on eye – Photophobia– Increased tear production– Spasm of the ocular muscles
Systemic EffectsSystemic Effects
• Photosynthesis of vitamin D following irradiation of skin by UVR in UV-B range– UVR can be used as treatment for
disorders of calcium and phosphorus metabolism, such as rickets and tetany
– Treatment of choice for such problems is dietary supplementation
• Photosynthesis of vitamin D following irradiation of skin by UVR in UV-B range– UVR can be used as treatment for
disorders of calcium and phosphorus metabolism, such as rickets and tetany
– Treatment of choice for such problems is dietary supplementation
Ultraviolet GeneratorsUltraviolet Generators
• Carbon arc lamp
• Xenon compact arc lamp
• Fluorescent ultraviolet lamp (blacklight)
• Mercury arc lamp
• Carbon arc lamp
• Xenon compact arc lamp
• Fluorescent ultraviolet lamp (blacklight)
• Mercury arc lamp
Carbon Arc LampCarbon Arc Lamp
• Composed of two carbon electrodes • Two electrodes move slightly apart
causing current to arc across small gap • UVR is emitted between 3500 and 4000
Å • Electrodes gradually burn and must be
replaced – Burning is noisy and causes an unpleasant
odor
• Composed of two carbon electrodes • Two electrodes move slightly apart
causing current to arc across small gap • UVR is emitted between 3500 and 4000
Å • Electrodes gradually burn and must be
replaced – Burning is noisy and causes an unpleasant
odor
Xenon Compact Arc LampXenon Compact Arc Lamp
• Composed of compressed xenon gas enclosed in a vessel
• Electric arc passed through gas • Gas is heated to 6000° C • Emits infrared, visible, and UVR in
range of 3200 to 4000 Å
• Composed of compressed xenon gas enclosed in a vessel
• Electric arc passed through gas • Gas is heated to 6000° C • Emits infrared, visible, and UVR in
range of 3200 to 4000 Å
Fluorescent UV Lamp(Blacklight)
Fluorescent UV Lamp(Blacklight)
• Low-pressure mercury lamp • Tube of UV-transmitting glass coated
with phosphors • Phosphors are fluorescing
substances that absorb the UVR and then reemit it at a longer wavelength
• UVR emitted ranges from 3000 to 4000 Å
• Low-pressure mercury lamp • Tube of UV-transmitting glass coated
with phosphors • Phosphors are fluorescing
substances that absorb the UVR and then reemit it at a longer wavelength
• UVR emitted ranges from 3000 to 4000 Å
Mercury Arc LampMercury Arc Lamp
• Most likely kind of UVR lamp to be used • Either low-pressure or high-pressure
mercury arcs – Mercury contained in a quartz envelope– An electric arc passes through vaporizing
mercury– At 8000° C atoms become incandescent
and emit ultraviolet, infrared, and visible light
• Most likely kind of UVR lamp to be used • Either low-pressure or high-pressure
mercury arcs – Mercury contained in a quartz envelope– An electric arc passes through vaporizing
mercury– At 8000° C atoms become incandescent
and emit ultraviolet, infrared, and visible light
Mercury Arc LampMercury Arc Lamp
• High-pressure = Hot Quartz• Most of UVR produced falls within UV-
B range• Mainly used to produce erythema and
accompanying photochemical reactions
• High-pressure = Hot Quartz• Most of UVR produced falls within UV-
B range• Mainly used to produce erythema and
accompanying photochemical reactions
Mercury Arc LampMercury Arc Lamp
• Low-pressure = Cold quartz lamp– Temperature of the quartz envelope is about 60° C – UVR spectrum limited to 1849 Å and 2537 Å – Does not require a warm up or cool down period, and is
used mainly where bactericidal effect of UVR is desired
• Low-pressure = Cold quartz lamp– Temperature of the quartz envelope is about 60° C – UVR spectrum limited to 1849 Å and 2537 Å – Does not require a warm up or cool down period, and is
used mainly where bactericidal effect of UVR is desired
Techniques of ApplicationTechniques of Application
• Effectiveness of lamp assessed by determining skin sensitivity to UVR – Measured by the minimal erythemal dose
(MED) • Exposure time needed to produce a faint
erythema of the skin 24 hours after exposure• Question patient regarding photosensitizing
drugs
– Area of skin to be tested should have pigmentation similar to area to be treated
• Effectiveness of lamp assessed by determining skin sensitivity to UVR – Measured by the minimal erythemal dose
(MED) • Exposure time needed to produce a faint
erythema of the skin 24 hours after exposure• Question patient regarding photosensitizing
drugs
– Area of skin to be tested should have pigmentation similar to area to be treated
Measuring MEDMeasuring MED
• Patient is draped except for test site• Piece of paper with five cutouts 1” square
and 1”apart placed over the test site • Height of lamp from patient adjusted to
same level as for treatment• Shutters are opened and cutouts exposed at
15-sec intervals 15, 30 , 45, 60, and 75 secs.
• Patient is draped except for test site• Piece of paper with five cutouts 1” square
and 1”apart placed over the test site • Height of lamp from patient adjusted to
same level as for treatment• Shutters are opened and cutouts exposed at
15-sec intervals 15, 30 , 45, 60, and 75 secs.
Determining MEDDetermining MED Patient returns in 24 hours and a visual
inspection determines MED • Areas tested that reveal no erythema 24 hours
after testing have received a suberythemal dose• Areas showing erythema at 24 hours have
received a minimal erythemal dose. • Erythema still present at 48 hours = 1st degree
erythemal dose • Erythema persists from 48-72 hours = 2nd degree
erythemal dose • Erythema lasts past 72 hours= 3rd degree
erythemal dose
Patient returns in 24 hours and a visual inspection determines MED • Areas tested that reveal no erythema 24 hours
after testing have received a suberythemal dose• Areas showing erythema at 24 hours have
received a minimal erythemal dose. • Erythema still present at 48 hours = 1st degree
erythemal dose • Erythema persists from 48-72 hours = 2nd degree
erythemal dose • Erythema lasts past 72 hours= 3rd degree
erythemal dose
Determining MEDDetermining MED
• 1st-degree and 2nd-degree doses can be estimated – 1st-degree erythemal doses
approximately correspond to 2.5 times minimal erythemal dose
– 2nd-degree doses correspond to 5 times minimal erythemal dose
• 1st-degree and 2nd-degree doses can be estimated – 1st-degree erythemal doses
approximately correspond to 2.5 times minimal erythemal dose
– 2nd-degree doses correspond to 5 times minimal erythemal dose
Determining MEDDetermining MED
• Since human skin adapts to UVR exposure, MED will gradually increase with repeated treatments
• Necessary to gradually increase exposure time to achieve the same reaction
• Once determined it is increased 5 seconds per treatment
• Height of lamp remains constant
• Since human skin adapts to UVR exposure, MED will gradually increase with repeated treatments
• Necessary to gradually increase exposure time to achieve the same reaction
• Once determined it is increased 5 seconds per treatment
• Height of lamp remains constant
Positioning The LampPositioning The Lamp
• Apply cosine law and inverse square law
• Distance of lamp must be kept constant if intensity of treatments is to be equal
• Generally standardized at each clinic usually ranging from 24 to 40 inches
• Apply cosine law and inverse square law
• Distance of lamp must be kept constant if intensity of treatments is to be equal
• Generally standardized at each clinic usually ranging from 24 to 40 inches
Treatment TechniqueTreatment Technique
• Patient should be draped and wear eye goggles
• Consistency in positioning of lamp is critical– Must be the same as in MED test
• Clinician must also wear goggles
• Open lamp shutters and begin timing simultaneously
• Patient should be draped and wear eye goggles
• Consistency in positioning of lamp is critical– Must be the same as in MED test
• Clinician must also wear goggles
• Open lamp shutters and begin timing simultaneously
Clinical ApplicationsClinical Applications
• Most common use of UVR is in treatment of dermatologic conditions such as psoriasis and acne and hard to cure infectious skin conditions such as pressure sores
• Development of oral and topical medications has greatly reduced the use of ultraviolet
• Most common use of UVR is in treatment of dermatologic conditions such as psoriasis and acne and hard to cure infectious skin conditions such as pressure sores
• Development of oral and topical medications has greatly reduced the use of ultraviolet
Indications for Ultraviolet TherapyIndications for Ultraviolet Therapy
• Acne • Aseptic wounds• Folliculitis• Pityriasis rosea• Tinea capitum• Septic wounds• Sinusitis• Psoriasis
• Acne • Aseptic wounds• Folliculitis• Pityriasis rosea• Tinea capitum• Septic wounds• Sinusitis• Psoriasis
• Pressure sores• Osteomalacia• Diagnosis of skin
disorders• Increased vitamin
D production • Sterilization• Tanning• Hyperplasia
• Pressure sores• Osteomalacia• Diagnosis of skin
disorders• Increased vitamin
D production • Sterilization• Tanning• Hyperplasia
Contraindications for Ultraviolet Therapy
Contraindications for Ultraviolet Therapy
• Porphyrias• Pellagra• Lupus erythematosus• Sarcoidosis• Xeroderma
pigmentosum• Acute psoriasis• Acute eczema • Herpes simplex
• Porphyrias• Pellagra• Lupus erythematosus• Sarcoidosis• Xeroderma
pigmentosum• Acute psoriasis• Acute eczema • Herpes simplex
• Renal and hepatic insufficiencies
• Diabetes• Hyperthyroidism• Generalized dermatitis• Advanced
arteriosclerosis• Active and progressive
pulmonary tuberculosis
• Renal and hepatic insufficiencies
• Diabetes• Hyperthyroidism• Generalized dermatitis• Advanced
arteriosclerosis• Active and progressive
pulmonary tuberculosis
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