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

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

PRODUCTIONS OF UVR

I. NATURAL WAY: SUN
510% 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

John Low
1. Kromayer lamp
2. Fluorescent lamp
Wadsworth
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.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

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 (7dehydrocholesterol) 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
 To accelerate skin growth, help control infection, sterilize skin surface temporarily

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

INDICATIONS OF UVR
3. Vitiligo
 T anning 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

Latent period
Appearan ce
Approx. duration of erythema
Skin edema
E1
6-12 hrs
Mildly pink
Less than 24 hrs
E2
6 hrs
Definite pink-red; blanches on pressure
E3 E4
3 hrs Less than
24 hrs
Very red;does not blanches on pressure
Angry red
2 days 3-5 days A week
None None Some Blisters

E1 E2 E3 E4
Skin discomfort
Desquamatio n
Relation to dose causing
E1
None Slight soreness; irritation
None
1
Powder y
2.5
Hot& painful
In thin sheets
5
Very painfu l
In thick sheets
10

SELECTION OF DOSAGE LEVEL
DOSAGE FREQUENCY
1. E1 or Minimal Erythemal
Dose may be given to total body area
2. E2  up to 20% of total body area
Given daily
Every second day
3. E3  up to 250 square cm of normal skin
Every third or fourth day
4. E4  up to 25 square cm of normal skin
Once a week or every forth night

CALCULATION OF UVR DOSAGE
Basis: determined by performing skin test to get MED or E1
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.) E1= determined by the skin test b.) E2= 2.5 x E1 c.) E3= 5 x E1 d.) E4= 10 x E1

If the E1 of the patient is 50 s at a distance of 200 mm, find E3 at
200 mm.

CALCULATION OF UVR DOSAGE
Progression of dosage: a.) E1 is progressed by 25% of the preceding dose b.) E2 is progressed by 50% of the preceding dose c.) E3 is progressed by 75% of the preceding dose

If E1 is 30 s at 200 mm, find the second progression (P2E1).

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

nt= ot x nd2 od2

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 E1 of the patient is 2 s I/C, find the E1 at
100 mm.

Using the air cooled lamp, if the E1 at 400 mm is 30 s, find the E1 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)