Uv radiation with types , generators , indication of ultraviolet light and contraindications of ultraviolet light and uses

1. ULTRAVIOLETRADIATION

2. Ultraviolet radiation (UVR) covers a small
part of electromagnetic spectrum lying
between the visible light and X-ray region.
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3. Typesof UVR
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Typesof UVR
UVA
400 – 315 nm, near UV
Effects: Erythema without pigmentation
UVB
315 – 280 nm, middle UV
Effects: Erythema without pigmentation,
formation of vit D,skin tanning(blister/burn)
UVC
280 – 100 nm, far UV
Kills bacteria, formation of vit. D,skintanning

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Production
• Therapeutic UVusually produced by the passage
of acurrent through an ionized vapour – often
mercury vapour
• at low pressure or hightemperatures.
Devicescommonly used are either
•air cooled (using air circulation withfan),
or
• water cooled (using awater jacketsurrounding
the burner with continually circulatingwater).

6. Mercury VaporLamp
• produced by mercury
vapor lamp
• which consists of a
quartz burner tube
containing traces of
argon gasand mercury
under reduced
pressure.
• An electrode is inserted
at each end of burner
tube.
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7. Mercury VaporLamp
• Thecurrent is applied to the
electrodes,
• causesthe formation of free
mercuryionsand electrons
• When free electrons are being
accelerated in the tube, many
collisions with neutral mercury
vapour atoms will occur:
• By elastic collisionsnot
affecting theatom
• By knocking an electron offthe
atom – ionization
• By moving an electron to a
higher energy level – excitation
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8. Fluorescentlamps
• Theseare low-pressure
mercury discharge tubes with
aphosphorcoating on inside.
• Theparticular wavelengths
andthe amount of each
emitted will dependonthe
compositionof the phosphor
used.(mixtures of
phosphates, borates, and
silicates.)
• Thisgives aconsiderable UVA
and UVBoutput but noUVC.
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9. TheraktinTunnel
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10. AlpineLamp
• Medium – PressureMercury
ArcLamp/ high-altitudelamps
• wavelength 253nm (short
wavelength) used in treatment
of generalised skin conditions
asacne and psoriasis.
• ShortUVRreact with oxygenin
the air to producea small
quantity of ozone(O3),
• Ozoneistoxicat high
concentrationssoventilation
shouldbeadequate around
these lamps.
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11. Kromayerlamp
• medium-pressuremercury
vapourlampsdesignedto be
usedin contactwith the
tissues,both onthe skin
surfaceandin body cavities.
• Water-cooled lamps,
wavelength at 366nmgive
both UVAand UVB,
• used for treating localised
lesions aspressure areas,
ulcers, shevesand sinusesin
open areas.
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Physiologicaleffects
• Immediate/acute effects
1. Erythema
2. Pigmentation
3. Increased skin growth
4. Vitamin Dproduction
5. Esophylactic effect
6. Immunosuppressive effects
7. Effects on eye

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Erythema
• Erythema is reddening
of the skin asaresult of
an inflammatory
reaction stimulated by
ultraviolet rays→
• release of histamine
and prostaglandin-like
substance from the
epidermis and
superficial dermis→
• dilatation of the
superficial dermal
blood vessel

14. •Another important cutaneous vasodilator, nitric
oxide has recently been shown to contribute in the
maintenance of erythema due to UVB.
•An Erythema appears sometimes after the
application of UVR, this is often a matter of hours
and is called as Latent Period.
• The effectiveness of UVR in producing erythema
, increases with decreasing wavelength
•To get an erythema equivalent to UVB , it require
a dose that is 100-1000 gtimes of UVA.

15. Degree of Erythema

16. Pigmentation
• Pigmentation or tanning of theskin follows
the erythema,
• its amount varies with the intensity of the
erythema.
• It is due to the increased deposition of the
pigment melanin formed in the basal celllayer
of the skin by the melanoblasts, and migrates
to the superficial layers ofthe epidermis.
• This process takes a little time and usually
noticeable about 2 days after exposure, this
delayed process of pigmentation is known as
tanning.

17. •The melanin forms an umbrella, over the
nucleus of the cell in order to protect it from
the further effect of the UVR.

18. Desquamation
• Is the casting off of
the cells which have
been destroyed by
the UVR, occurs at
the early stage of skin
growth.
• Desquamation or
peeling is
proportional to the
intensity of the
erythema.

19. Vitamin Dproduction
• UVBisable to convert
sterolsinthe skin,suchas
7-dehydro-cholesterolto
vitamin D
• vitamin Dis required to
assist in the absorption of
calcium and phosphorous
from the intestine toblood
stream.
• Suberythemaldosesof UVB
are adequate to promote
vitamin Dsynthesis(280-
300nm)
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20. TheEsophylactic effect
• Theresistance of the body to infection is
increased asaresult of stimulation of reticulo-
endothelial system→
• antibodies against bacteria and toxins.

21. ImmunosuppressiveEffects:
• UVdestroysLangerhan’scellsandstimulates
the proliferation of suppressorTcells.
• (Tcells are regulatory in that theyinhibit
antibody production)
• This immunosuppressive effects may
contribute to the development ofskincancer.
• In short, UVradiation induces astate of
relative immunosuppression that prevents
tumor rejection.

22. R
Effectson eye
• Strong dosesof UVBand Cradiation to the eyescanlead
to conjunctivitis(corneaalongwitheyelid
inflammation) and photokeratitis (inflammation of
cornea)resultsin irritation of the eye,a feeling of grit
in the eye,watering of the eyeandaversionto light
(photophobia)
• In severe casesintense pain and spasmofthe eyelid may
be present. Thisis also known as‘snowblindness’
• While UVBand Care absorbed in the cornea, UVAcan
pass through to be absorbed mainly in the lens of the
eye.
• Thestrong dosesof UVAmay lead to formationof
cataracts.

23. Physiologicaleffects
• Long term/chroniceffects
1. Solar elastosis or aging
2. Cancer

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SolarElastosis& Ageing
• Prolonged exposure of UVR lead to
premature ageing of the skin;this is
especially soin the fair-skinned.
• decreasedfunctionof sebaceousandsweat
glands
• lossof elastictissue
• Theskinbecomeswrinkled, dry,and leathery.

25. C
ancer
• skincancers,basalcellandsquamouscell
carcinomas.
• Carcinogenesis is a danger, as short UV rays
may have an effecton DNA and thus on cell
replication.
• shorter ultraviolet wavesshould be avoided
and coursesof treatment should notexceed
four weeks.

26. UVRdosage
• Skinresponse to UVRdependsupon:
1. Quantity of UVRenergy applied to theskin
2. Biological responsiveness of skin

27. UVRdosage
1. Quantity of UVRenergy applied to theskin
which depends upon:
a) Output of thelamp
b) Distance between the lamp and theskin
c) Angle at which radiation fall on theskin
d) Time for which radiations are appliedon
the skin

28. UVRdosage
2. Biological responsiveness of skin:

29. Erythemal response

30. TestDose
30 sec. 60 sec. 90 sec.
A minimal dose (MED) is the length of the ultraviolet
exposure required to produce a mild erythema, which
appears within 6 to 8 hours and still just visible after 24
hours.

31. TestDose
T
estapplied
11.00am
Monday
Monday Tuesday
3pm 7pm 11pm 7am 11am
Lookat the areas at the times shown and place atick in the box if anyrednessis seen.
If no rednessis seenput across

32. Calculation of dosage
E1is determined from the skin test and theother
erythemal dosages can be calculated asfollows:
• Suberythemal 75%of E1.
• E2=2.5 xE1.
• E3=5 xE1.
• E4=10 xE1.
• Double E4=20 xE1.
• E4& Double E4are used on open wounds.

33. Progressionof UV dosage
Doses can be progressed asfollows:
• Suberythemal – previous dose plus 12.5%.
• E1 – previous dose plus25%.
• E2 – previous dose plus50%.
• E4 – previous dose plus75%.
Dosagesused on open wounds are not
progressed becausethere is no epidermisto
thicken.

34. Alteration of the intensitywith distance
• T
oirradiate asmaller area the source is moved
nearer to the patient but the time of exposure
must be altered to maintain the same
intensity in accordance with the law of inverse
squares.
Now time =Old time x(newdistance)2
(Old distance)2

35. Therapeuticuses
• Psoriasis
1. Goeckermanregimen
2. Ingram/Leedsregimen
3. Photochemotherapy
• Acne Vulgaris
• Eczema
• Chronic
infection/wound
• Vitiligo
• Protection for
hypersensitive skin
• Vitamin Ddeficiency
• Mild hypertension
• Pruritis
• Psychological benefits
• Non infected wounds
• Intact skin

36. Psoriasis
• Chronicskin condition of unknown
reason, manifested as silvery scales
covering the pink or red plaque
which presents localized plaques. In
which the rate of cell turnover from
the basal layer through to the
superficial layer is too rapid. From 28
to 45-70 days is being reduced to 5
days
• Theaim of ultraviolet irradiation is to
decrease the rate of DNAsynthesisin
the cells of the skin and thus slow
down their proliferation
(immunosuppressive effect of UVR).

37. Psoriasis
GoeckermanRegimen:
• This consists of coal tar applications 2 to 3 times a
day with general (total body) UVB radiation given
once aday asasuberythemal or E1 dose.
Ingram or LeedsRegimen:
• Thepatient hasacoaltar bath before being
irradiated with aminimal erythema doseof UVB;
• the psoriatic lesions are covered with dithranol.
• Next day the dithranol is cleaned off and theprocess
is repeated.

38. Psoriasis
Photochemotherapy : (PUVA)
•Psoriasis can be treated with radiation of UVA, accompanied by
sensitizer
• Psoralen-type drug is given to the patient some 2 hours
previously,to make him/her sensitive to UVAradiations,
• Thiswill produce an erythema at lower intensitiesthan
normal.
• Thedrug 8-methoxy-psoralen is used making the patient
highly reactive to UVAonce it hasbeen absorbed, for some
6
– 8 hours.
• Asthe peak of PUVAerythema occursat 48 – 72 hours,
treatment shouldbegiventwice a week until clearance.
• Thisshouldbeapproximately 12 –18 exposures.

39. AcneVulgaris:
• Thisis achronic
inflammatory condition
of the pilosebaceous
unit especiallyaffecting
the face, chest,and
back.
• Using UVRis aiming to
produce desquamation
to open the blocked
pores and hair follicles.
• usuallyE2areused

40. Eczema:
• an inflammatory response
inthe skin,with associated
oedema, itchingwith
redness,scaling,vesicles,
andexudationof serumon
the skin.
• It may be causedbycontact
dermatitis, atopiceczema.
• It is often these who can
benefit from mildultraviolet
treatment.
•
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41. Infected Wound
• treated with high dosesofultraviolet
radiation.
• A Kromayer lamp is successful in
inhibiting bacterial colony growth.
• Thedosesgivenmustbean E4.capableof
killingthebacteria,andcausingminimal
erythema andtanning.

42. Non-Infected Wounds
• the aim of ultraviolet radiation isto stimulate
the growth of granulation tissueandthus
speedup repair.
• Canbe used in surgical incisions, pressure
areas, venous and arterial ulcers.
• UVA,E3dose issufficient.

43. Incipient pressureareas
• UVRmay be used to
prevent pressure areas from
breaking down and
• stimulate the growthof
epithelial cells and to
destroy the surface
bacteria.
• E1dose progressed daily
using the Kromayerlamp.
• In areas such as the heels or
the elbows where the skin is
thicker, an E2may beused.

44. Vitiligo
• an autoimmune disease in
which destruction of
melanocytes in local areas
causeswhite patches to appear
on the skin.
• Both UVAand Bstimulate
melanocyte activity
• UVAseemsto provoke adarker
and long-lasting tan although
the protective effects do not
seem to be somarked
• UVBprovokes more thickening

45. Protection for Hypersensitive Skin
• Polymorphiclight eruptionis the commonest
of photodermatoses
• increasedtoleranceto sunlightcanbe
achievedbya courseof UVB
• start with avery low dose andgradually
progressing.

46. Vitamin DDeficiency
• Vitamin D3isformedin skinbythe action of
UVBandCon 7-dehydrocholesterol.
• natural sunlight canalso be curativefor
vitamin Ddeficiencydiseases

47. Mild Hypertension
• Thegeneral (whole body)suberythemal
dosesof UVBcansignificantly lower blood
pressure
• it is believed to be due to calcium regulating
hormones associated with increased vitaminD
production.

48. Pruritus
• The intractable and serious itching thatcan
occur due to raised bile acid level in biliary
cirrhosis or uraemia.
• cansuccessfullytreated bysuberythemal
whole-bodyUVBeither alone or in
combinationwith the drugcholestyramine.

49. PsychologicalBenefit
• patients expect to feel betterand
• the consequent tanning makesthem look
better.

50. Contraindicationsto UVR
• Acuteskinconditions– acute eczema,dermatitis, lupus
erthematosis(auto-immune disease) and herpessimplex
• an existing ultravioletErythema.
• Skindamagedueto ionizingradiations – deep X-ray
therapy.
• Photoallergy – allergic reaction to ultravioletradiation.
• Acutefebrile illness– whole-body treatment should be
avoided.
• Recentskin grafts.

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Dangers
• Shock: the machine should be earthed and the main powercord
insulation intact.
• Eyes:it is important to protect the eyesof both patient and
therapist from scattered and reflected radiations. Thepatient
should wear goggleseven when not facing the source ofradiations.
Thephysiotherapist should be aware of the cumulative effect of
UVRthrough theday.
• Over dosage: to avoid long exposure to UVR,use an accurate timing
device especially for periods over about 1 minute. Overlap of doses
may lead to burn.
• In case of an accidental overdose infrared radiation may be given
to the area in an attempt to increase local circulation and thereby
disperse the histamine-like substance that produces theerythema.
• Sensitization: anumber of drugs and some foods in few patients
canalter the effect of UVRand causesensitivity.

52. References
1. Electrotherapy Explained by Low andReed
2. http://faculty.ksu.edu.sa/68417/RHS%20321/ULTRAVIOLET%20%20RADI
ATIONS%20(2).pdf
3. http://www.aarogya.com/conditions-and-
diseases/specialties/physiotherapy/4823-electrotherapy.html?start=2
4. Ultraviolet Radiation by SagarNaik. physio4all
5. Ultraviolet germicidal irradiation: current best practices by StephenB.
Martin, Jr.et al.ASHRAEJournal,August,2008