2 ULTRAVIOLET RADIATION (UVR) Radiation between the visible light & X-ray sections of the electromagnetic spectrum. (J. Ritter)VISIBLE LIGHTIRRUVRRADIO f
3 NATURE OF UVR 1. Strongly absorbed in air (*short-wavelength UVR) 2. Behave like visible radiation in terms of properties (reflection, refraction, transmission and absorption)3. Transmit more energy, thus, producing more chemical changes not just simply heat
4 CATEGORIES OF UVR UVB UVC UVA Wavelength (nm) Other Names 320-400 Other NamesLongMediumShortBlacklightErythemalGermicidalNearFar
5 CATEGORIES OF UVRNear UVR- nearer the visible light spectrum but are longer in wavelength*Longer wavelength are more beneficial (BIOTIC)Shorter wavelength are ABIOTIC
6 PRODUCTIONS OF UVRI. NATURAL WAY: SUNII. ARTIFICIAL WAY
7 I. NATURAL WAY: SUN5-10% of the sun’s energy is in the UVR range ( nm)UVA 6.3% of sunlight during summer; UVB 0.5%Both UVA & UVB can be involved in sunburn and skin diseases
8 II. ARTIFICIAL WAYPassage of electric current thru gas (vaporized mercury)Collision with the electrons flowing between the lamp’s electrodesMercury atoms become excitedExcited electrons return to particular electronic states in the mercury atomRelease some of the energy they have absorbedRADIATION
9 II. ARTIFICIAL WAYUVR can be produced if the temperature is high enough and pressure is lowUVR= T° P°
11 KROMAYER LAMP a.k.a. water-cooled lamps requires pre-heating of 5 minutesa medium pressure mercury vapor designed to be used in contact with the tissue (i.e. treatment of localized pressure areas and ulcers).
12 A. KROMAYER LAMPwavelengths of the rays produced are concentrated at 366 nm but a wide range of both UVA & UVB are produced.
19 D. LOW PRESSURE MERCURY VAPOR DISCHARGE TUBES Components:a. Tube or envelope made of quartz or special glass to allow UVR to pass throughb. Metal electrodes sealed in the ends of the tubec. Electric circuit to regulate electric current
20 PHYSIOLOGIC EFFECTS 1. Erythema or redding & tanning - only encountered when UVB (at nm) treatment is used.Minimal Erythemal Dose = smallest UVR dose to result in erythema that is just detectable by eye between 8-24 hrs after exposure
21 PHYSIOLOGIC EFFECTS 2. Pigmentation - results from formation of melanin in deep regions of the skin & migration of melanin noticeable about 2 days after exposure- UVB at 300 nm
22 PHYSIOLOGIC EFFECTS 3. Hyperplasia - occurs at 72 hrs using UVB 4. Increase skin growth- increase keratinocyte cell turnover so that skin grows more rapidly for a time leading to shedding of most superficial cells at an earlier stage
23 PHYSIOLOGIC EFFECTS 5. Vitamin D production - UVB convert sterols in the skin (7-dehydrocholesterol) to vitamin D at nm6. Destruction of bacteria-occurs by suppressing DNA and RNA synthesis at UVB at nm
24 PHYSIOLOGIC EFFECTS 7. Wound healing - using UVB at 260-280 nm 8. Increase production of RBC9. Stimulation of steroid metabolism- UVR promotes vasomotor responses causing antirachitic effect
25 PHYSIOLOGIC EFFECTS 10. Immunosuppressive effects - UVB destroys Langerhans cells & stimulate proliferation of suppressor T cells
26 PHYSIOLOGIC EFFECTS 11. Conjunctivitis / photokeratitis / cataract - conjunctivitis occur at UVB with 270 nm- cataracts at UVA since it can pass thru the eye’s lens
27 PHYSIOLOGIC EFFECTS12. Premature aging of the skin (dry, wrinkled, decreased function of sebaceous and sweat glands)13. Skin cancers14. Psychological effects
28 INDICATIONS OF UVR 1. Skin diseases a.) Psoriasis treatment b.) Acne vulgaris treatmentTo accelerate skin growth, help control infection, sterilize skin surface temporarily
29 INDICATIONS OF UVR2. Healing of wounds (venus ulcers & pressure sores)To increase rate of skin growth and to provide antibiotic effect
30 INDICATIONS OF UVR 3. Vitiligo 4. Protection of hypersensitive skin Tanning and thickening of the skin4. Protection of hypersensitive skin
31 INDICATIONS OF UVR5. Alopecia6. Treatment of vitamin D deficiency
32 INDICATIONS OF UVR 7. Pruritus due to biliary cirrhosis or uremia 8. Jaundice for newborn babies
33 CONTRAINDICATIONS 1. Acute skin conditions (acute eczema, dermatitis) 2. Skin damage due to ionizing radiations like deep X-ray therapy
34 CONTRAINDICATIONS3. Systemic lupus erythematosus can be triggered or exacerbated4. Photoallergy / photosensitivity (albinism will not tolerate UVR)
35 CONTRAINDICATIONS 5. Porphyrias (rare metabolic disorder) 6. Pellagra (dermititis due to severe niacin deficiency)
37 PRECAUTIONS Patients with: a.) little pigmentation, often seen in blondes and redheads.b.) conditions like syphilis, alcoholism, cardiac or renal disease, acute psoriasis, acute eczema, elderly and infants.
38 PRECAUTIONSc.) Ingested certain food like strawberries, eggs or shellfish before treatment.d.) Taking any of the ff: birth control, pills, tetracycline, diuretics and insulin.e.) Recent superficial heat treatment before UVR radiation.
39 DANGERS OF USING UVR 1. Eyes (conjunctivitis) 2. Overdose (too long exposure; too close to the lamp)3. Previously protected skin4. Electric shock5. Burns6. Chill7. Sensitizers8. Change of lamp
40 Approx. duration of erythema LEVELS OF UVR ERYTHEMAE1E2E3E4Latent period6-12 hrs6 hrs3 hrsLess than 24 hrsAppearanceMildly pinkDefinite pink-red; blanches on pressureVery red;does not blanches on pressureAngry redApprox. duration of erythema2 days3-5 daysA weekSkin edemaNoneSomeBlisters
42 SELECTION OF DOSAGE LEVEL FREQUENCY1. E1 or Minimal Erythemal Dose may be given to total body areaGiven daily2. E2 up to 20% of total body areaEvery second day3. E3 up to 250 square cm of normal skinEvery third or fourth day4. E4 up to 25 square cm of normal skinOnce a week or every forth night
43 CALCULATION OF UVR DOSAGE Basis: determined by performing skin test to get MED or E1Two units of measurements to consider:a.) length of time (seconds)b.) distance from the lamp (mm)
44 CALCULATION OF UVR DOSAGE Levels of dosage intensitya.) E1= determined by the skin testb.) E2= 2.5 x E1c.) E3= 5 x E1d.) E4= 10 x E1
45 If the E1 of the patient is 50 s at a distance of 200 mm, find E3 at 200 mm.
46 CALCULATION OF UVR DOSAGE Progression of dosage:a.) E1 is progressed by 25% of the preceding doseb.) E2 is progressed by 50% of the preceding dosec.) E3 is progressed by 75% of the preceding dose
47 If E1 is 30 s at 200 mm, find the second progression (P2E1).
48 CALCULATION OF UVR DOSAGE Alteration of intensity with distance-guided by Law of Inverse Square which states that as the distance between the source and the patient increases, the intensity decreases in proportion to the square of the distance.Formula: I = 1/ d2
50 CALCULATION OF UVR DOSAGE Using Kromayer lamp:-use the levels of dosage for intensity since the distance is always at 25 mm.Using air-cooled lamps:-distance is from the burner of the lamp to the patient and follow the Inverse square law formula.
51 Using the kromayer, if the E1 of the patient is 2 s I/C, find the E1 at 100 mm.
52 Using the air cooled lamp, if the E1 at 400 mm is 30 s, find the E1 at 200 mm.
53 CALCULATION OF UVR DOSAGE Using an applicator:1.) Compute for coefficient of the applicator:*Length of applicator in mm divided by 252.) Compute for applicator dose:*in-contact dose (secs at mm) x coefficient of applicator (in mm)