ULTRAVIOLET RADIATION UVR Radiation between the visible light

ULTRAVIOLET RADIATION (UVR) Radiation between the visible light & X-ray sections of the electromagnetic spectrum. (J. Ritter) RADIO f IRR VISIBLE LIGHT UVR

NATURE OF UVR 1. Strongly absorbed in air (*shortwavelength 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

CATEGORIES OF UVR UVA Wavelength (nm) Other Names UVB UVC 320 -400 290 -320 200 -290 315 -400 280 -315 100 -280 Long Medium Short Blacklight Erythemal Germicidal Near Far

CATEGORIES OF UVR Near UVR- nearer the visible light spectrum but are longer in wavelength *Longer wavelength are more beneficial (BIOTIC) Shorter wavelength are ABIOTIC

PRODUCTIONS OF UVR I. NATURAL WAY: SUN II. ARTIFICIAL WAY

I. NATURAL WAY: SUN 5 -10% of the sun’s energy is in the UVR range (180 -400 nm) UVA 6. 3% of sunlight during summer; UVB 0. 5% Both UVA & UVB can be involved in sunburn and skin diseases

II. ARTIFICIAL WAY Passage of electric current thru gas (vaporized mercury) Collision with the electrons flowing between the lamp’s electrodes Mercury atoms become excited Excited electrons return to particular electronic states in the mercury atom Release some of the energy they have absorbed RADIATION

II. ARTIFICIAL WAY UVR can be produced if the temperature is high enough and pressure is low UVR= T° + P°

ARTIFICIAL UVR APPARATUS John Low Wadsworth 1. Kromayer lamp 1. Water-cooled lamp (Kromayer lamp) 2. Fluorescent lamp 3. Medium pressure mercury arc lamp (Alpine Sunlamp) 4. Low pressure mercury vapor discharge tubes 3. Air-cooled lamp (Alpine Sunlamp)

A. KROMAYER LAMP a. k. a. water-cooled lamps requires pre-heating of 5 minutes a medium pressure mercury vapor designed to be used in contact with the tissue (i. e. treatment of localized pressure areas and ulcers).

A. KROMAYER LAMP wavelengths of the rays produced are concentrated at 366 nm but a wide range of both UVA & UVB are produced.

B. FLUORESCENT LAMPS low-pressure mercury discharge tubes with a phosphor coating on the inside absorbs short UVR which causes excitation of the phosphor atoms and remission at a longer wavelength

B. FLUORESCENT LAMPS gives considerable UVA & UVB output; NO UVC more commonly used for Psoriasis affecting large body areas

C. ALPINE SUN LAMP a. k. a air-cooled lamps generally used for treatment of generalized skin conditions like Acne and Psoriasis Usually applied at a distance of 45 -50 cm

D. LOW PRESSURE MERCURY VAPOR DISCHARGE TUBES Components: a. Tube or envelope made of quartz or special glass to allow UVR to pass through b. Metal electrodes sealed in the ends of the tube c. Electric circuit to regulate electric current

PHYSIOLOGIC EFFECTS 1. Erythema or redding & tanning - only encountered when UVB (at 250 -297 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

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

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

PHYSIOLOGIC EFFECTS 5. Vitamin D production - UVB convert sterols in the skin (7 dehydrocholesterol) to vitamin D at 280 -300 nm 6. Destruction of bacteria -occurs by suppressing DNA and RNA synthesis at UVB at 250 -270 nm

PHYSIOLOGIC EFFECTS 7. Wound healing - using UVB at 260 -280 nm 8. Increase production of RBC 9. Stimulation of steroid metabolism - UVR promotes vasomotor responses causing antirachitic effect

PHYSIOLOGIC EFFECTS 10. Immunosuppressive effects - UVB destroys Langerhans cells & stimulate proliferation of suppressor T cells

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

PHYSIOLOGIC EFFECTS 12. Premature aging of the skin (dry, wrinkled, decreased function of sebaceous and sweat glands) 13. Skin cancers 14. Psychological effects

INDICATIONS OF UVR 1. Skin diseases a. ) Psoriasis treatment b. ) Acne vulgaris treatment l To accelerate skin growth, help control infection, sterilize skin surface temporarily

INDICATIONS OF UVR 2. Healing of wounds (venus ulcers & pressure sores) l To increase rate of skin growth and to provide antibiotic effect

INDICATIONS OF UVR 3. Vitiligo l Tanning and thickening of the skin 4. Protection of hypersensitive skin

INDICATIONS OF UVR 5. Alopecia 6. Treatment of vitamin D deficiency

INDICATIONS OF UVR 7. Pruritus due to biliary cirrhosis or uremia 8. Jaundice for newborn babies

CONTRAINDICATIONS 1. Acute skin conditions (acute eczema, dermatitis) 2. Skin damage due to ionizing radiations like deep X-ray therapy

CONTRAINDICATIONS 3. Systemic lupus erythematosus can be triggered or exacerbated 4. Photoallergy / photosensitivity (albinism will not tolerate UVR)

CONTRAINDICATIONS 5. Porphyrias (rare metabolic disorder) 6. Pellagra (dermititis due to severe niacin deficiency)

CONTRAINDICATIONS 7. Acute febrile illness (pulmonary tuberculosis, severe cardiac involvement, acute diabetes mellitus) 8. Recent skin graft

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.

PRECAUTIONS c. ) 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.

DANGERS OF USING UVR 1. Eyes (conjunctivitis) 2. Overdose (too long exposure; too close to the lamp) 3. Previously protected skin 4. Electric shock 5. Burns 6. Chill 7. Sensitizers 8. Change of lamp

LEVELS OF UVR ERYTHEMA Latent period Appearance E 1 6 -12 hrs E 2 6 hrs E 3 3 hrs Mildly pink Definite Very pink-red; does blanches on not pressure blanches on pressure Approx. Less than 2 days 3 -5 days duration of 24 hrs E 4 Less than 24 hrs Angry red A week erythema Skin edema None Some Blisters

LEVELS OF UVR ERYTHEMA E 1 E 2 E 3 E 4 Skin discomfort None Slight soreness; irritation Hot& painful Very painful Desquamation None Powdery In thin sheets In thick sheets Relation to dose causing E 1 1 2. 5 5 10

SELECTION OF DOSAGE LEVEL DOSAGE 1. E 1 or Minimal Erythemal Dose may be given to total body area FREQUENCY Given daily 2. E 2 up to 20% of total body area Every second day 3. E 3 up to 250 square cm of normal skin Every third or fourth day 4. E 4 up to 25 square cm of normal Once a week or every forth skin night

CALCULATION OF UVR DOSAGE Basis: determined by performing skin test to get MED or E 1 Two units of measurements to consider: a. ) length of time (seconds) b. ) distance from the lamp (mm)

CALCULATION OF UVR DOSAGE Levels of dosage intensity a. ) E 1= determined by the skin test b. ) E 2= 2. 5 x E 1 c. ) E 3= 5 x E 1 d. ) E 4= 10 x E 1

If the E 1 of the patient is 50 s at a distance of 200 mm, find E 3 at 200 mm.

CALCULATION OF UVR DOSAGE Progression of dosage: a. ) E 1 is progressed by 25% of the preceding dose b. ) E 2 is progressed by 50% of the preceding dose c. ) E 3 is progressed by 75% of the preceding dose

If E 1 is 30 s at 200 mm, find the second progression (P 2 E 1).

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/ d 2

nt= ot x nd 2 od 2

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.

Using the kromayer, if the E 1 of the patient is 2 s I/C, find the E 1 at 100 mm.

Using the air cooled lamp, if the E 1 at 400 mm is 30 s, find the E 1 at 200 mm.

CALCULATION OF UVR DOSAGE Using an applicator: 1. ) Compute for coefficient of the applicator: *Length of applicator in mm divided by 25 2. ) Compute for applicator dose: *in-contact dose (secs at mm) x coefficient of applicator (in mm)