ultraviolet radiation final (2)

8/6/2019 Ultraviolet Radiation Final (2)

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Ultraviolet radiation (UVR) covers a small part

of electromagnetic spectrum lying betweenthe violet end of the VI IB IVI IB I and XX--

II .


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The radiations introduced to the tissues

through 1.subcutaneous tissue, 2.hair

follicles, and 3.sebaceous glands.


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1. Sunburn (UVB)UVB) / Erythema ( Reddening of theskin)

2. Tanning of the skin / Pigmentation

3. Decrease in sensitivity of the skin (IncreasedEpidermal thickness)

4. Premature aging of the skin (UVA)UVA)

5. Skin cancer (UVB)UVB)6. Exposure to the eye causesphotokeratitis

(UVB)UVB)

7. Photosynthesis of vitamin D


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1. Reflection

2. Refraction

3. Absorption

4. Penetration


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1. UVA (Long UV) 400 315nm. {penetrates todermis, Responsible for development of slow natural

tan}

2. UVB (medium UV, erythemal UV)

315 280nm. {Produces new pigment formation,

sunburn, Vitamin D synthesis. Responsible for

inducing skin cancer}

3. UVC (short UV, germicidal UV)

280 100nm {Does not reach the surface of the

earth}


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1. High pressure mercury vaporlamp Air cooled.

2. High pressure mercury vapor

lamp Water cooled ( Kromayer

lamp).

3. Fluorescent lamps


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The therapeutic UVR are

produced by mercury vapourlamp which consists of aQUARTZ BURNERTUBEQUARTZ BURNERTUBEevacuated from air andcontaining traces of argonargon

gas and mercury undergas and mercury underreduced pressurereduced pressure.

An electrode is inserted ateach end of burner tube. The

current is applied to theelectrodes, the mercuryvapour and the passage ofelectrons through the vapourestablishes the UVR.


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The UV apparatus is grouped as follows:

1- Air-cooled lamps: Hanovia Alpine SunLamp, {High pressure vapour lamps}wavelength253nm (short wavelength) used in treatment of

GENERALISEDSKINCONDITIONSASACNEANDGENERALISEDSKINCONDITIONSASACNEANDSORIASIS.SORIASIS.


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Emit ultraviolet, infrared, and

visible light

UVR produced falls within UV-Brange

Mainly used to produce

erythema and accompanying

photochemical reactions


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The heat produced inside the Burner or Quartz

tube causes some of it to change to another

form of silica called TRIDYMITE.TRIDYMITE.

Tridymite is OPAQUEOPAQUE to UVR. So output of therays tends to FALL.

A variable resistancevariable resistance is included in the burnercircuit to increase the potential difference

across the burner & intensity of the current.


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The photochemical action of UVR shorter

than 250nm250nm in wavelength onatmospheric oxygen is to form OZONEOZONE.

Ozone is a toxic gas for inhalation &

partly prevented by good ventilation.

Levels of ozone can be detected by smell.


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Water-cooled lamps:

Kromayer lamp, wavelength at 366nmgive both UVA and UVBUVA and UVB, used fortreating localised lesions as pressurepressure

areasareas, ulcersulcers, and sinusessinuses in open areas.

It is a water cooled mercury vapor

lamp.

Eliminates the danger of an IRRburn.


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1. It must be kept dry.2. It should not be turned on & off more

frequently.

3. After 1000hrs of use the burner must be

renewed.

4. The burner of an air cooled lamp should be

cleaned regularly with absolute alcohol.

5. The burner should not be touched with

fingers.

6. After every 8hrs of use the distilled water

should be renewed.


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It used for GENERAL UV

IRRADIATION.

The spectrum contains a

large proportion of short UVRwhich are undesirable for the

general treatment.


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Theraktin lamp consists of a number of

fluorescent tubes each with a parabolic reflectorincorporated into a semicircular tunnel.

The wavelength between 290 and 350nm (UVA

long) used in treating affecting large areas.


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This provides an even irradiation to patients.

It allows treatment of the whole body in 2

halves.

2 IRR elements are included in order to keep

the patient warm during treatment.

All of the lamps should be positioned at least

18 from the patient


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UVA Dermis level.

UVB Deep Epidermis


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The UVR physiological effectsmay be divided into 2 groups;

1. Local Effects which produced

locally in the area.

2. General Results from awidespread Irradiation.


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1. Dilation of capillaries H-substance

2. Dilation of arterioles Axon reflex

3. Exudation of fluids into the tissues

Increased permeability of the capillary walls.


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Sometimes immediate tanning occurs as aresult of effects of PREPRE--EXISTINGEXISTINGmelaninmelanin. This may occur within minutesof exposure.

Sun / Carbon arc Brown color

Mercury Vapor lamp Grayish

The pigmentation REDUCESREDUCES the

penetration of UVB.


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UVR provokes an increased

reproduction of KERATINOCYTES.

This leads to thickening of epidermiswhich acts does acts a PROTECTION

AGAINSTTHE RAYS.

So longer doses are required to

repeat an ERYT

HEMAL reaction.


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Destructive effects ofultraviolet radiation include

the destruction of viruses,bacteria, and other small

organisms on the skin surface

such as FUNGI commonly foundin wounds. (effect of UVB).


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1. Vitamin D Production

In the presence of UVB, converts 77--DehydrocholestrolDehydrocholestrolinto VitaminVitamin DDthrough chemical reaction.chemical reaction.

Vitamin D is required to assist in theabsorption ofabsorption ofcalcium and phosphorouscalcium and phosphorous from the intestine to blood

stream.


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General UVA Irradiation

Stimulation of reticuloreticulo -- endothelial systemendothelial system

Ingest bacteria & produce ANTIBODIESANTIBODIES against

BACTERIA TOXINSBACTERIA TOXINS.

So the resistance of the body to infection is

increased & this being known as

ESOPHYLACTIC EFFECT.


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Its being claimed that because ofGeneral UV Irradiation has a

GENERALTONICEFFECT,GENERALTONICEFFECT,

APPETIT

IE S

LEEPBEING I

MPROVEDAPPET

IT

IE S

LEEPBEING I

MPROVED

NERVOUSNESS IRRITABILITYNERVOUSNESS IRRITABILITY

DECREASEDDECREASED


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The principle therapeutic uses of UVR are of SKIN

DISEASES1. PSORIASIS:PSORIASIS:--

It is a skin condition which presents localized THICKPINK /THICKPINK /REDREDplaques, sharply demarcated & covered with SILVERYSILVERY

SCALES.SCALES.

In this state the aim of UVR irradiation is to decrease thedecrease theDNA synthesis in the cells of the skin to improve the skinDNA synthesis in the cells of the skin to improve the skinconditioncondition


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Acne is also a skin condition which presents PUSTULES,PUSTULES,

PAPULESPAPULES formed by blocking of sebaceous pores hairblocking of sebaceous pores hairfollicles affecting mainly the face, chest back.follicles affecting mainly the face, chest back.

The more severe & long lasting forms cause disfiguringdisfiguring

serious distress.serious distress.

Using UVR is aiming to produce desquamation to opendesquamation to open theblocked pores and hair follicles.

E2 dose is given to the face, chest and neck.


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It is an INFLAMMATORYRESPONSEINFLAMMATORYRESPONSEinthe skin associated with OEDEMA.

The patient suffers marked ITCHINGITCHINGwith REDNESS, SCALING, VESCILESREDNESS, SCALING, VESCILES &exudation of serum on the skin.

A mild UVR treatment will help. (Sub(Sub

acute Chronic stage)acute Chronic stage)


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Infected wounds such as

1.1. ULCERSULCERS

2.2. PRESSURESORESPRESSURESORES

3.3. SURGICAL INCISIONSSURGICAL INCISIONSare often treated with HIGH

DO

SES of UVR.

The aim of UVR irradiation is to destroy the surfacebacteria, remove the (SLOUGH) infected materialremove the (SLOUGH) infected material

&promote repair.promote repair.

E3 doseE3 dose is sufficient, the dose is may be given dailyand is not being applied to normal skin.


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It is a condition in which destruction of

MELANOCYTESMELANOCYTES in local areas causes WHITEPATCHESto appear on the skin.

Both UVA & UVB stimulate melanocyte activity.

UVA seems to provoke a DARKER LONGERLA

ST

INGTA

NNING.

UVB provokes more THICKENNING.more THICKENNING.


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The aim of UVR is to stimulatethe GROWTH ofGRANULATIONGROWTH ofGRANULATION

TISSUE SPEEDUPREPAIRTISSUE SPEEDUPREPAIR.

UVA stimulates GROWTH.

Example for non infected wounds

are Venous / Arterial ulcers.Venous / Arterial ulcers.


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It is used to produce a strongcounter irritation effect over

the site of DEEP SEATED PAIN.

E4 doseE4 dose is given to cause

discomfort and producing maskmaskof pain .of pain .


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5. Upper respiratoryUpper respiratorycondition managementcondition management Common Cold.

6. Counter Irritant Effect.


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1. Pulmonary TuberculosisPulmonary Tuberculosis

2. Severe cardiac disturbancesSevere cardiac disturbances

3. Systemic Lupus ErythematosisSystemic Lupus Erythematosis

4. Severe DiabetesSevere Diabetes

5. Dermatolo ical ConditionsDermatolo ical Conditions


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6. Known Photosensitivity.Known Photosensitivity.

7. Photosensitizing medication.Photosensitizing medication.

8. Deep xDeep x Ray therapy.Ray therapy.

9. Acute Febrile illnessAcute Febrile illness

10. Recent skin grafts.


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PorphyriasPorphyrias

PellagraPellagra

SarcoidosisSarcoidosis

Xeroderma pigmentosumXeroderma pigmentosum

Acute psoriasisAcute psoriasis

Renal and hepaticRenal and hepatic

insufficienciesinsufficiencies

HyperthyroidismHyperthyroidism

Generalized dermatitisGeneralized dermatitis

AdvancedAdvanced

arteriosclerosisarteriosclerosis

Acute eczemaAcute eczema

Herpes simplexHerpes simplex

Hypersensitivity toHypersensitivity to

sunlightsunlight


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1. ShockShock

2. EyesEyes - UVR may produce conjunctivitis,iritis or cataract.

3. Over DosageOver Dosage UVR burn can occur.

Mainly E4 reaction

4. OzoneOzone Important to ensure adequate

Ventilation in the area.


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1. Eyes protection.


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Sunscreen doesnt offerSunscreen doesnt offer100%100%protection.protection.

SPF(Sun Protection Factor) 30+SPF(Sun Protection Factor) 30+

sunscreensunscreen blocks 96% ofUV;SPF15+blocks 96% ofUV;SPF15+blocks out 93%.blocks out 93%.

In addition to sunscreen,In addition to sunscreen, wear a hat,wear a hat,sunglasses, more clothing, and seeksunglasses, more clothing, and seekshade.shade.


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Most cotton andMost cotton andcotton/polyestercotton/polyesterfabrics protectfabrics protectagainstagainst 95% of95% ofUV,UV, but are lessbut are less

effective if wet,effective if wet,faded, or aged.faded, or aged.


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It is used to assess the individual patients(ERYTHEMAL)(ERYTHEMAL) reaction to uvr irradiation.

The basis for any calculation of any UVRdosage is the MED (MINIMALERYTHEMALMED (MINIMALERYTHEMALDOSE)DOSE)

This MED refers to the response ofthe response oferythemaerythema for the dose to be given


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1. The area chosen for the test is of

importance.2. Because the patient is to inspect atBecause the patient is to inspect at

regular intervals a convenient, visible site isregular intervals a convenient, visible site is

essential.essential.3. It should be clear of skin disease.It should be clear of skin disease.

4. The FLEXOR SURFACE of the FOREARM is theThe FLEXOR SURFACE of the FOREARM is the

most usual site.(Other sites aremost usual site.(Other sites are Abdomen,Abdomen,

Medial aspect of arm / thigh)Medial aspect of arm / thigh)

5. The selected site should be cleaned with

soap & water to remove surface grease.


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7. Three to Five holes of at least 2cm & 1cm

apart are cut in a piece oflint/paper/cardboard is taken for irradiation of

UVR along with a slide cover to pull up to

reveal one opening at a time.


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8. This cutting is fixed to the forearm with adhesive

plaster.9. The cuttings are of different sizes & shapes in-

order to make IDENTIFICATIONOFTHEERYTHEMAIDENTIFICATIONOFTHEERYTHEMAEASIEREASIERfor the patient.

10. Allow the lamp to warm up according to themanufacturer instructions.

11. Place the lamp PERPENDICULAR to the area being

tested (Forearm) & a DISTANCE of 60 to 90cms from

the site.

12. Expose the 1st opening for 30sec, then expose the

2nd opening for another 30sec & go on till the last

opening


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13. So the 1st opening would receive the longest

exposure time & the last opening would receive theleast amount of exposure time.

14. Switch off the lamp

15. Instruct the patient to MONITOR the forearm

every 2hrs & note which opening or shape appeared

pink / red first&

when it faded / disappeared.

16. The patient is also given a card similar to the

opening to make a note.


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It is a slight reddening

(erythema) of the skinwhich takes from 6 8hrs

to develop&

which is stilljust visible at 24hrs.


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Degreeof

Erythema

Latent

periodIn HRS

Appearancecolor

Durationof

Erythema

SkinOedema

Skindiscomfort

Desquamation of

skin

Relationto

E1Dose

E1 6-8 Mildly pink


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The skin response to UVR depends on;

1. The quantity of UVR energy applied to unit area of

the skin.(Depends on);

a) The output of lamp Make, Type, Aging

b) Distance between the lamp & the skin Inverse

square law

c) Angle at which radiations fall on the skin cosine

lawd) Time for which radiations are applied

2. The sensitivity of the skin


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E1/MED is the basic of UV calculation

which is determined for each individualpatient by performing a skin test.

From this point all other doses of UVR

can be calculated.

E2 = 2 x E1

E3 = 5 x E1

E4 = 10 x E1


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EXAMPLE:

If the E1 dose of the patient is 25sec, calculate

the E3 dose?

E1 dose = 25sec

E3 dose = 5 x E1

E3 dose = 5 x 25 = 125sec


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The dose at different distances from the lamp

to skin can be calculated by formula;

NEWDOSE = OLD DOSE X NEW DISTANCE

OLD DISTANCE


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An exposure to UVR should not be repeated until the

erythema caused by a previous dose has faded.

Thickening of the epidermis

Necessary to increase the exposure in order to repeat theerythemal reaction at each successive dose

Doses are progressed as follows:

To repeat an E1 25% of the preceding dose is added




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Examples of progression of dosage

If E1 is 30sec, find the second progression (P2E1)?

E1= 30sec

P1(Day one progression)E1 = E1 + 25% of E1 =

30 +30/4 = 30 + 7.5 =37.5sec

P2(Day two progression)E1 = P1E1 + 25% of

P1E1 = 37.5 +37.5/4 = 46.9sec

P2E1 = 47sec


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1. An E1/MED Given to the total body area

(Whole body)

2. An E2 - May not be given to up to 20% of

total body area

3. An E3 May not be given to up to 250cm of

normal skin

4. An E4 May only be given to an area up to

25cm of normal skin.


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A number of drugs & some foods in a few

patients are known to sensitize patients to theeffects of UVR.

Commonly seen sensitizing groups are;1. psoralens - Sensitizer

2. Sulphonamides - Antibiotic

3. Phenothiazine Tranquilizer4. Barbiturates

5. Gold therapy

ultraviolet radiation final (2)

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