Ultraviolet radiation can be used therapeutically to treat various skin conditions. It has both immediate physiological effects like erythema, tanning, and long term effects like aging and cancer. There are different types of UV generators that produce UVA, UVB or UVC. Dosage is carefully determined based on skin type and response. PUVA treatment uses oral photosensitizing drugs before UVA exposure to treat conditions like psoriasis. Precautions must be taken with UV therapy due to risks of overexposure like burns, aging and skin cancer.

1. ULTRA VIOLET
RADIATION
KEERTHI PRIYA MPT NEURO,
ASSISTANT PROFESSOR

2. CONTENTS
INTRODUCTION
TYPES
PRODUCTION
PHYSIOLOGICAL EFFECTS
THERAPEUTIC EFFECTS
SENSITIZERS
INDICATIONS
PRECAUTIONS

3. INTRODUCTION
Ultraviolet radiation (UVR) covers a small part of electromagnetic spectrum
lying between the visible light and X-ray region.
Electromagnetic waves which is invisible to human eye wave length is between 10-400nm
Frequency =0.75X1015 HZ to 3X1015 HZ.
Properties Of Reflection, Refraction &
Absorption, Penetration.
Penetration Depends On:
• Wave Length ,
• Thickness
• Amount Of Melanin
Absorption Is more in air
Transfer of energy is more which causes chemical changes

4. TYPES OF UVR : NATIONAL RADIOLOGICAL PROTECTIVE BOARD
1. UVA 400 – 315 nm, Near/ Long UV, Black light
2. UVB 315 – 280 nm, Middle UV , Medium/ Erythemal UV
3. UVC 280 – 100 nm, Far/Short UV, Vacuum UV /Germicidal UV
BIOTIC
ABIOTIC

5. PRODUCTION
IONIZATION
VAPORISATION
RELEASE OF PHOTON
GENERATORS OF UVR:
 Low Pressure Mercury Vapour Burner
Kromayer Lamp
Fluorescent Lamp
Therakitn Tunnel
PUVA Apparatus

6. Mercury vapour
lamp
 Burner U- shaped, quartz tube containing
traces of argon gas and mercury under reduced
pressure.
 Ends of the tube are closed with metal caps
and electrodes are fixed .
 The electrodes are connected to an AC

7. Mercury vapour
lamp
 Current of 400 volts are passed into the
circuit.
 Ionization of argon takes place
 Followed by vaporization of mercury & also
release of photon

8. Conversion of quartz to silica- tridymite.
Trydimite causes opacity of the burner
output of lamp gradually falls as tridymite
increases.
As quartz changes to tridymite, resistance reduced,
intensity of current increased.
Trydimite Formation

9. Cooling:
A portion of output of burner is infra red
which is converted to heat.
For safety lamp is placed at 50 cm from
treatment area.
Ozone Formation
Shorter UV (<250 nm) converts oxygen to ozone .
Ozone toxic gas hazards are prevented by good
ventilation
Levels detected by smell at extremely low levels

10. Kromayer Lamp
Medium-pressure mercury vapour lamps designed to be used in contact with the
tissues, both on the skin surface and in body cavities.
Water-cooled lamps, wavelength at 366nm give both UVA & UVB,
Used for treating localized lesions as pressure areas, ulcers, shelves and sinuses
in open areas.

11. Fluorescent Lamps
These are low-pressure mercury discharge tubes with a phosphor coating on inside.
The particular wavelengths and the amount of each emitted will depend on the composition of
the phosphor used. (mixtures of phosphates, borates, and silicates.)
This gives a considerable UVA and UVB output but no UVC.

12. Theraktin Tunnel
Semi cylindrical frame which are mounted with four fluorescent tubes
Each tube mounted in its own reflector in such a way that an even irradiation of patient is
produced.
Whole body treatment in 2 halves
Normally fluorescent tubes with a spectrum of 280-400 nm used

13. PUVA Apparatus
Irradiation with UVA only may be performed with special fluorescent tubes, mounted in a vertical
battery on a wall or
On four sides of a box totally surrounding patient
This is given two hours after patient has taken photoactive drug- Psoralen, hence Psoralen ultra
violet A

14. PHYSIOLOGICAL EFFECTS
Immediate/acute effects
1. Erythma
2. Pigmentation
3. Increased skin growth
4. Vitamin D production
5. Esophylactic effect
6. Immunosuppressive effects
7. Effects on eye

15. Erythema
Erythma is reddening of the skin as a result of an inflammatory reaction stimulated by ultraviolet
rays .
Time period between exposure to appearance of erythema is said to be latent period
→Release of histamine,prostaglandins & prostacyclins substance
→ Dilatation of the capillaries and arterioles in dermis and exudation of fluid into skin

16. Pigmentation
Pigmentation or tanning of the skin follows the erythma, due to stimulation of melanocytes.
Increased deposition of the pigment melanin formed in the basal cell layer of the skin by the
melanoblasts, and migrates to the superficial layers of the epidermis.
Formation & migration of melanin
Appears 2 days after exposure
Melanin forms an umbrella
Decreases penetration of UV

17. Desquamation
 Desquamation is the casting off of the cells which have been destroyed by the UVR,
 Desquamation is peeling of skin & is proportional to the intensity of the erythema
 Increases UVR penetration

18. Vitamin D Production
UVB is able to convert sterols in the skin, such as 7-dehydro-cholesterol to vitamin D
vitamin D is required to assist in the absorption of calcium and phosphorous from the intestine to
blood stream.
Suberythmal doses of UVB are adequate to promote vitamin D synthesis

19. Thickening Of Epidermis
 Stimulation of keratinocytes.
Increases cell turnover
Decreases penetration of UVR

20. Immunosuppressive Effects
UV destroys Langerhan’s cells and stimulates the proliferation of suppressor T cells.
T cells are regulatory in that they inhibit antibody production
In short, UV radiation induces a state of relative immunosuppressant that prevents tumor
rejection.
The resistance of the body to infection is increased as a result of stimulation of reticulo-
endothelial system → antibodies against bacteria and toxins.

21. Effects On Eye
Strong doses of UVB and C radiation to the eyes can lead to conjunctivitis and photokeratitis.
Results in irritation of the eye, a feeling of grit in the eye, watering of the eye and aversion to light
(photophobia).
In severe cases intense pain and spasm of the eyelid may be present. This is also known as ‘snow blindness’
While UVB and C are absorbed in the cornea, UVA can pass through to be absorbed mainly in the lens of the
eye.
The strong doses of UVA may lead to formation of cataracts.

22. - Long term/chronic effects:
1. Solar elastosis or ageing
2. Cancer
PHYSIOLOGICAL EFFECTS

23. Solar Elastosis & Ageing
Ageing accelerated with continuous exposure to UVR
Thinning of epidermis, loss of epidermal ridges, loss of melanocytes, dryness due to poor
functioning of sebaceous and sweat glands
Wrinkling due to lack of dermal connective tissue

24. Often seen in members of fair skinned races in sunny climate- Australia, South Africa/ faces of
farmers and sailors- wrinkling marked
Sunbathers- cautious of cumulative and deleterious effects of prolonged UV exposure

25. Antibiotic Effect
Short UV rays destroy bacteria and other small organisms- fungi commonly found in wounds
E4 dose effectively destroys all such organisms

26. Cancer
Cancer - skin cancers, basal cell and squamous cell carcinomas.
Carcinogenesis is a danger, as these rays may have an effect on DNA and thus on cell replication.
Shorter ultraviolet waves should be avoided and courses of treatment should not exceed four
weeks.

27. DOSAGE
Skin response to UVR depends upon:
1. Quantity of UVR energy applied to the skin
2. Biological responsiveness of skin

28. 1. Quantity of UVR energy applied to the skin which depends upon:
a) Output of the lamp
b) Distance between the lamp and the skin
c) Angle at which radiation fall on the skin
d) Time for which radiations are applied on the skin

29. Biological responsiveness of skin:
Erythma response-
A minimal erythmal dose (MED) is the length of the ultraviolet exposure required to produce a
mild erythma, which appears within 6 to 8 hours and still just visible after 24 hours.

30. Erythema
Damage to cells causes release of histamine like substances from epidermis and superficial
dermis
Gradual diffusion of this until sufficient accumulated around blood vessels in skin- dilate- latency
of erythma
Erythmal reaction used to classify doses of UVR given to patients
E1- appears last and disappears first.

31. Four degrees of erythma-
Dose Latency
period
(hours)
appearance pigmentation desquamation
E1 Upto 12 Slightly pink Nil Nil
E2 4-6 Red Slight Powdery
E3 1-4 Fiery red and
painful
marked In sheets
E4 As E3 but with blisters

32. CALCULATION OF TEST DOSE
Test Dose - 30 sec. 60 sec. 90 sec.
Calculation of dosage E1 is determined from the skin test and the other erythmal dosages can be
calculated as follows:
Suberythmal 75% of E1.
E2 = 2.5 x E1.
E3 = 5 x E1.
 E4 = 10 x E1.
 Double E4 = 20 x E1.
 E4 & Double E4 are used on open wounds.

33. Progression of UV dosage - Doses can be progressed as follows:
Suberythmal – previous dose plus 12.5%.
E1 – previous dose plus 25%.
E2 – previous dose plus 50%.
E3 – previous dose plus 75%.
Dosages used on open wounds are not progressed because there is no epidermis to
thicken.

34. Alteration of the intensity with distance
To irradiate a smaller 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.
New time = Old time x (new distance)2 (Old distance)2

35. Skin types:
I - always burn, never tan
II - always burn, slight tan
III - sometimes burn, always tan
IV - never burn, always tan
V - moderately pigmented skin
(Mediterranean, Mongoloid)
VI - heavily pigmented - black

36. SENSITIZERS
The substances which increase absorption of ultraviolet rays are said too be sensitizers.
Sensitizers are of 2 types:
1. Oral Drugs: Psoralins, Sulphonamids, Tetracyclins, Aspirin, Hypnotic Drugs,
2. Tropical Applicants: Coal Tar, Dithranol

37. THERAPEUTIC USES
Psoriasis
Acne Vulgaris
Chronic infection/wound
Vitiligo
Protection for hypersensitive skin
Vitamin D deficiency

38. Mild hypertension
Pruritis
Psychological benefits
Non infected wounds

39. THERAPEUTIC USES
Psoriasis - a skin condition, which presents localized plaques in which the rate of cell turnover
from the basal layer through to the superficial layer is too rapid.
The aim of ultraviolet irradiation is to decrease the rate of DNA synthesis in the cells of the skin
and thus slow down their proliferation (immunosuppressive effect of UVR).

40. Goeckerman Regimen
This consists of coal tar applications 2 to 3 times a day with general (total body) UVB radiation
given once a day as a suberythmal or E1 dose.

41. Ingram or Leeds Regimen
The patient has a coal tar bath before being irradiated with a minimal erythma dose of UVB;
the psoriatic lesions are covered with dithranol.
Next day the dithranol is cleaned off and the process is repeated.

42. Psoriasis Photo chemotherapy
Psoralen-type drug is given to the patient some 2 hours previously, to make him/her sensitive to
UVA radiations
This will produce an erythma at lower intensities than normal.
The drug 8-methoxy-psoralen is used making the patient highly reactive to UVA once it has been
absorbed, for some 6 – 8 hours.

43. As the peak of PUVA erythma occurs at 48 – 72 hours, treatment should be given twice a week
until clearance.
This should be approximately 12 –18 exposures.

44. Effect of psoralen- in nucleus, binds to DNA in presence of UVA- inhibits DNA synthesis and cell
division
UV dosage measured in J/ cm2, so output measured
Dosage depends on skin type and progression made according to energy density applied than
length of time

45. Acne Vulgaris
This is a chronic inflammatory condition of the pilo-sebaceous unit especially affecting the face,
chest, and back.
Using UVR is aiming to produce desquamation to open the blocked pores and hair follicles.
Usually E2 dosage used

46. Eczema
An inflammatory response in the skin, with associated oedema, itching with redness, scaling,
vesicles, and exudation of serum on the skin.
It may be caused by contact dermatitis, atopic eczema.
It is often these who can benefit from mild ultraviolet treatment.

47. Infected Wound
Treated with high doses of ultraviolet radiation.
A Kromayer lamp is successful in inhibiting bacterial colony growth.
The doses given must be an E4.

48. Non-Infected Wounds
the aim of ultraviolet radiation is to stimulate the growth of granulation tissue and thus speed up
repair.
Can be used in surgical incisions, pressure areas, venous and arterial ulcers.
UVA, E3 dose is sufficient.

49. Incipient pressure areas
UVR may be used to prevent pressure areas from breaking down,
stimulate the growth of epithelial cells and to destroy the surface bacteria.
E1 dose progressed daily using the Kromayer lamp.
In areas such as the heels or the elbows where the skin is thicker, an E2 may be used.

50. Vitiligo
An autoimmune disease in which destruction of melanocytes in local areas causes white patches
to appear on the skin.
Both UVA and B stimulate melanocyte activity
UVA seems to provoke a darker and long-lasting tan although the protective effects do not seem
to be so marked
UVB provokes more thickening

51. Protection for Hypersensitive Skin
Polymorphic light eruption is the commonest of photo dermatoses
Increased tolerance to sunlight can be achieved by a course of UVB
Start with a very low dose and gradually progressing.

52. Vitamin D Deficiency
Vitamin D3 is formed in skin by the action of UVB and C on 7-dehydrocholesterol.
natural sunlight can also be curative for vitamin D deficiency diseases

53. Mild Hypertension
The general (whole body) Suberythmal doses of UVB can significantly lower blood pressure
It is believed to be due to calcium regulating hormones associated with increased vitamin D
production.

54. Pruritus
The intractable and serious itching that can occur due to raised bile acid level in biliary cirrhosis
or uraemia.
Can successfully be treated by Suberythmal whole-body UVB either alone or in combination with
the drug cholestyramine.

55. Psychological Benefit
Patients expect to feel better and the consequent tanning makes them look better.

56. PRINCIPLES OF APPLICATION
General irradiation- UVB
Using Theraktin lamp; patient lies on plinth, head and feet protrude out of tunnel, receive
lesser dose
Distance from lamp 50cm
Patient warned not to touch tunnel or lamp, treatment given for appropriate time
Position changed and next half of treatment completed

57. Treatment given daily, E0 (suberythmal dose) for whole body, or half body(1 side) with E1, or
whole body with E1 on alternate days
At each treatment, dose increased proportionately
For UVB treatment, E1 raised to b/w 3-5 times original E1; extent of progression depends on skin
type
Due to danger of carcinoma, 4- week courses and 20-minute maximum applications recommended

58. PUVA treatment
Used to sensitize pts to UVA, for Rx of psoriasis, eczema, vitiligo and PLE prophylaxis
Pts given 8-MOP by mouth and exposed to UVA 2-3 hrs later
Given grey/ green glass to wear when sensitized- time of taking tablets to 8 hrs later
Warned not to expose to sun for atleast 8 hrs from ingestion

59. For small area or resistant, topical preparation of 8-MOP applied (concentration on skin higher
than tablet, UVA dose lower)
Test dose given- whole body dose of UVA given to produce mild erythma at 3 days/
suberythmal
Rx for 2 times a week, progression weekly for several weeks

60. After 2/3 weeks, marked pigmentation seen as UVA stimulates melanin production
UVA does not thicken stratum corneum- exposure to UVA minimum/ no protection to UVB
UVA- skin changes similar to ageing and has carcinogenic effect – sessions limited and recorded;
cataract with high doses

61. UVB and low dose PUVA effective on psoriasis; high PUVA best for few pts not improved with
UVB or low UVA
UVB equally effective as UVA, safe and economical
Maintenance dose of UVB and UVA given weekly, fortnightly or monthly intervals to prevent
recurrence of psoriasis

62. Local application with air cooled Alpine lamp
Lamp on 5 min before use- UV output peak
Part to be Rxed exposed and cleaned to remove grease
Position part to be Red conveniently and comfortably; test dose given
Distance 50 cm, at right angles to skin
Dose increased for subsequent sessions
Same exposed area Rxed subsequent sessions

63. UVR for face
Close eyes with cotton wool secured by petroleum jelly, protect eyelids
Treatment given in 2/3 different angles- front nose nearer, sides- ears nearer,
smear with petroleum jelly
Similarly for lips to avoid discomfort

64. Local Rx with Kromayer lamp
Focal Rx, applied to open wounds or skin close to wound in order to
-kill bacteria
-promote inflammation in tissues to control infection and
-promote skin growth
E4/ double E4 for infected areas
E1 or E2 to surrounding skin

65. New epithelium growth- avoid Rx or E0 through blue uviol filter- filters out red end of
visible spectrum and all UVR below 290nm
E3 for clean indolent non-skin area not healing
UVR from Kromayer bactericidal but does not penetrate into deep tissues

66. Surface to be Rxed and Kromayer face cleaned with moist swab, face applied on or close to open
area
Surrounding skin protected from E4 by cut hole in double thickness lint or paper or strips of wet
cotton wool or gauze around skin edge and covering area beyond with dressing towels

67. Larger area- apply lamp at distance of 10cm
Dose applied to infected area large than skin, skin dose additionally
applied to open wound
Avoid spread of infection from open wound
Quartz window cleaned with alcohol wipes after Rx; no further
sterilization ??

68. Applicators
Kromayer fitted with quartz rod applicators to convey UVR into narrow sinuses or under
overhanging wound edges
Applicator fitted into holder with finger operated shutter mounted on quartz face of Kromaye
Are of various shapes and sizes

69. UVR passes through quartz without diverging due to total internal reflection- very effective
because of high refractive index b/w air and quartz (1.46, critical angle of 44 degrees)
In water, it is lower(1.1 C angle 65.5 degrees)
More UVR leaks from sides of applicator in tissues

70. More of UV absorbed in applicator- dose increased when used
Test applicator to be used with estimated E1 on normal skin
When lamp used at a distance from skin, change in relative proportions of UVB and UVC
due to greater absorption of UVC in air

71. CONTRAINDICATIONS TO UVR
Acute skin conditions – acute eczema, dermatitis, lupus erythmatosis (auto-immune
disease) and herpes simplex
an existing ultraviolet Erythma.
Skin damage due to ionizing radiations – deep X-ray therapy.
Photo allergy – allergic reaction to ultraviolet radiation.
Acute febrile illness – whole-body treatment should be avoided.
Recent skin grafts.

72. DANGERS
Shock: the machine should be earthed and the main power cord insulation intact.
Eyes: it is important to protect the eyes of both patient and therapist from scattered and reflected
radiations.
The patient should wear goggles even when not facing the source of radiations.
The physiotherapist should be aware of the cumulative effect of UVR through the day.
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 the
erythma.

73. REFERENCES
1. ELECTROTHERAPY EXPLAINED BY JOHN LOW & REED
2. ELECTROTHERAPY THEORY & PRACTICE BY ANGELA
3. THERAPEUTIC MODALITIES FOR SPORTS MEDICINE AND ATHLETIC TRAINING W I L L I A M E . P R E N T I C E
4. TEXT BOOK OF ELECTROTHERAPY BY JAGMOHAN SINGH

75. THANK YOU