uv rays and role in health

1. ULTRAVIOLET RADIATION
AB 1

2. PHYSICAL PROPERTIES OF UVR
• Ultraviolet (UV) Radiation is
electromagnetic radiation with the
following properties:
• Frequency range of 7.5x1014 to over
1015 Hz
• Wavelength from 400nm to below 290
nm
• The frequency of UV radiation lies
between that of X-rays and visible light
• UV is divided into three bands
 UVA----320 to 400 nm (long waves
produces fluorescence)-little or no
physiological effect
 UVB----290 to 320 nm (middle waves
produces skin erythema)-sun burn and
age related skin changes
 UVC----less than 290 nm (short waves
AB
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3. AB 3

4. PHYSIOLOGICAL EFFECTS
Can produce localized and
generalized effects
• Erythema reaction
• Thickening of
epidermis
• Desquamation
• Pigmentation
• Solar elastosis and
aging
• Antibiotic effect
• Vitamin D formation
• General tonic effect
• Cancer
AB
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5.  ERYTHEMA REACTION:
• The severity of erythema depends on the
intensity of chemical reaction produced by the
release of Histamine substance
• Release of H substance produces triple
response like dilatation of capillaries, dilatation
of arteries, exudation.
AB
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6. DEGRES OF ERYTHEMA:
Depending upon severity of chemical reaction and cessation
time, erythema is divided into four degrees
• First degree erythema(E1):
Characterized by slightly pink skin with no irritation. It
subsides with in 24 hours
• Second degree(E2):
Reddening with slight irritation, it subsides in two or
three days
• Third degree (E3):
Obvious reddening of the skin, painful which is hot,
sore and edematous, the reaction lasts for about a
week with pigmentation and peeling of skin.
• Fourth degree erythema (E4):
Here all the third degree erythema changes are
present but in addition to this there is blister formation
AB
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7. AB 7

8.  PIGMENTATION :
• Ultraviolet rays causes conversion of the amino
acid
tyrosine into the pigment melanin
• It is more in those with dark skin than with fair
skin.
 SOLAR ELASTOSIS AND AGING:
• Aging of the skin due to
 Thinning of the epidermis
 Loss of epidermal ridges
 Loss of melanocytes and dryness of skin
AB
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9. AB 9

10. AB 10

11.  THICKENING OF EPIDERMIS:
Ultraviolet rays causes sudden over activity of the
basal
layer of epidermis and leading to thickening of skin.
 DESQUAMATION:
The increased thickness of the epidermis is lost as
it dies out.
The process by which dead cells are casted off is
known
as peeling
 CANCER:
Long exposure may have an effect on DNA and
thus
increases the cell division and cell multiplication.
AB
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12. AB 12

13.  ANTIBIOTIC EFFECT:
• Short ultraviolet rays can destroy bacteria and
other
micro organism commonly found in wounds.
• E4 dose can effectively destroy all such organisms
found in wound.
 VITAMIN D FORMATION:
• Ultraviolet rays may cause conversion of
dehydrocholestrol into vitamin D (7-DHS is
present in
sebum of the skin).
AB
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14. AB 14

15. THERAPEUTIC EFFECTS
 EFFECT ON ACNE:
• An erythema will bring more blood to the skin
and
improves the skin condition
• Desquamation will remove the damaged skin
cells
• It produce a sterilizing effect on the skin
• An E2 dosage is used.
 EFFECT ON PSORIASIS:
• The aim is to decrease the rate of DNA
synthesis in
the cells of the skin and thus to reduce the
growth. AB
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16.  EFFECT ON SKIN WOUNDS:
 INFECTED WOUNDS
 The aim is destroy the bacteria, remove the
slough(dead material) and promote healing.
 E3 or E4 dosage is used
 NON-INFECTED WOUNDS:
 The aim is to promote the healing of wound, an E1
dosage is used.
 EFFECT ON ALOPECIA:
 Causes reduced hair fall and growth of new hairs.
 PAIN RELIEF:
 Ultraviolet rays may cause irritation of superficial
sensory nerve endings , cause pain relief through
counter irritation (E3 dosage)
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17. INDICATIONS
• Psoriasis
• Acne
• Chilblains (The cold exposure damages
capillary beds in the skin, which in turn can
cause redness, itching, blisters, and
inflammation)
• Bedsores
• Alopecia
• Sluggish wounds (Ulcers, pressure sores or
surgical incisions)
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18. CONTRAINDICATIONS
1) Fever
2) Acute eczema (dermatitis- skin infection)
3) Irradiation into the thoracic region in the
presence of
pulmonary tuberculosis
4) Following X-ray therapy
5) Hypersensitive individuals
6) Systemic lupus erythematosus (autoimmune
diseases,
resulting in inflammation and tissue damage)
7) Photo allergy and skin grafts
8) Cardiac, kidney or liver disease
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19. DANGERS AND PRECAUTIONS
 Conjunctivitis
• Avoiding the exposure of eyes by using dark
glasses,
using shades around the lamp
 Overdose
• Overdose can be prevented by carrying out test
dosage on patients before application
 Electric shocks
• Electric shock can be prevented by regular
checkups for leakage of current and proper
earthen
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20.  Burns
• Burns can be avoided by asking the patient not
to
touch any part of the lamp
 Chilling sensation
• Maintaining the adequate room temperature and
simultaneous irradiation of patient with Ultra
violet
rays can prevent chill.
 Cancer
• Avoid prolonged use of UVR
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21. APPLICATION TECHNIQUES
 when applying UV radiation for therapeutic
purposes, one must first determine the
individual patient’s sensitivity to UV radiation
 This varies widely among the individuals and
can be affected by skin pigmentation, age, prior
exposure of UV radiations and use of
sensitizing medications
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22. DOSE-RESPONSE ASSESSMENT
The UV dose is graded according to the individual’s
erythemal response and is categorized as follows:
 Suberythemal dose (SED): no change in skin
redness occurs in the 24 hours after UV exposure
 Minimal erythemal dose (MED): the smallest dose
produces erythema within 8 hours after exposure that
disappears within 24 hours after exposure
 First degree erythemal dose (E1): Definite redness
with some mild desquamation appears within 6 hours
after exposure and lasts for 1 to 3 days
AB
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23. • Second degree erythema (E2): intense
erythema with edema, peeling and pigmentation
appears within 2 hours or less after treatment
and is like a severe sunburn
• third degree erythema (E3): erythema with
severe blistering, peeling and exudation.
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24. ULTRAVIOLET THERAPY APPLICATION
1. Place UV goggles on patient and clinician
2. Remove all clothing and jewelry and wash the
area least exposed to sunlight.
 The areas usually used are the volar forearm,
abdomen or the buttocks
3. Take a piece of cardboard and cut four square
holes
4. Place the cardboard on the test area and drape
the area around the cardboard so that the
surrounding skin will not be exposed to the UV
radiation
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25. 5. Place the lamp 60 to 80 cm away and
perpendicular to the area exposed. Record and
measure the distance of the lamp from the
exposed area
6. Cover all but not one hole in the cardboard
7. Turn on the lamp after it becomes warm, direct
the beam to the area exposed and start the timer
8. After 120 sec uncover the second hole
9. After another 60 secs uncover the third hole
10. After another 30 secs uncover the fourth hole
11. After another 30 secs turn off the lamp
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26. • According to the protocol, the first window is exposed
for 240 secs, second window for 120 secs, third for 60
secs and fourth for 30 secs
• The patient should observe the area for next 24 hours
after exposure
• Once the test dose is determined, the part to be
treated
is positioned in such a way that the radiations will
strike
the area at right angles
• The distance between the burner of the lamp and the
skin is carefully measured; usual distance is 50 cm
• After irradiation is completed the part is immediately
rescreened or the lamp switched off if not further
required.
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27. AB 27

28. PROGRESSION OF DOSAGES
 Doses can be progressed as follows:
• Suberythema: previous dose plus 12.5%
• E1: previous dose plus 25%
• E2: previous dose plus 50%
• E3: previous dose plus 75%
• Or it can be simply one minute per session
 Number of sessions depend upon the condition
of the patient
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