ULTRAVIOLET LIGHT

I. INTRODUCTION
A. Description
B. History
C. Physical Principles
1. photochemical reaction
2. latent erythemal response
3. wavelengths
a. UVA 320-400 nanometers
b. UVB 290-320 nanometers
c. UVC 180-290 nanometers
4. near versus far bands - definition and effects
a. near - antirachitic and pigmentation
b. far - erythema and pigmentation

II. PURPOSE AND EFFECTS
A. Local
1. erythema
2. vasodilation - wound healing
3. stimulate stratum germinativum
a. epidermis layers thicken and get tougher
b. stratum corneum(horny, hornlike)
c. stratum lucidum(translucent)
d. stratum granulosum(granular, little grain)
e. stratum germinativum(basal cells)
4. increases desquamation - exfoliation
5. increases pigmentation - increases melanin production(name two conditions that lack melanin)
a. bactericidial - good for wound healing, sterilize water and air

B. General Effects
1. produce vitamin D - a substances which aides energy processes
2. helps in Ca and P++ absorption from intestine - is antirachetic
3. Ca and P++ must be present in body before vitamin D is effective, example third world countries increased incidence of rickets a. produces antibodies against infections by stimulating reticuloendothelial cells in deep epidermis

C. Ultraviolet versus Infrared effects

D. Wavelength effects of UV

E. Degree of erythema depends on the following factors
1. patient sensitivity
2. intensity of radiation
3. distance from radiation source
4. angulation of radiation
5. duration of exposure
6. skin texture
a. flexor versus extensor
b. blondes/redheads versus brunettes

III. UVL GENERATORS
A. Hot quartz or Air-cooled high pressure mercury vapor lamps
1. UV in all three bands and visible violet
2. tube of argon gas into which mercury has been placed
3. high voltage electric current vaporizes mercury producing UVL
4. reflector focuses rays
5. shutters provide for protection of eyes - keratitis and conjunctivitis, possibly leading to cataracts
6. treatment
a. general
b. application distance greater than 15 inches

B. Cold Quartz
1. low temperature
2. 90% of output is in C band range
3. smaller in physical size, used for local treatment only
4. portable
5. bacteriocidal, little pigmentation(a desirable feature)
6. used close to the skin
7. treatment a. local b. wounds c. infections d. local dermatitis

IV. INDICATIONS
A. Local
1. acne vulgaris(thick epidermal layer trapping sebum)
2. pressure sores - slow healing wounds
3. counterirratation (E2-E3 dose) for pain relief

B. General
1. psoriasis
a. PUVA or photosensitizaton of UVA, ingest psoralen to enhance absorption of 360 NM wavelength
b. TUVAB or tar and UVA and B(Goeckerman regimen)
2. analgesic to nerve endings
3. general tonic effect
4. upper respiratory infections
5. antirachitic
6. psychological
7. uremic pruritis

V. CONTRAINDICATIONS
A. active pulmonary TB
B. severe cardiac, kidney, metabolic, or liver diseases
C. severe diabetes(itching may occur)
D. sytemic lupus erythematosus
E. fever
F. post X - ray treatment
G. sarcoidosis

VI. PRECAUTIONS
A. photosensitivity
1. albinism
2. blondes and redheads
3. photosensitive drugs - sulfas, gold salts, quinine, insulin, birth control pills
4. syphilis
5. alcohol
6. heat(IR) before UVL treatment
7. foods - strawberries, eggs, shell fish
8. pregnancy

B. Sunglasses
1. UVB is absorbed by cornea(cornea repairs itself quickly)
2. lens is primary concern
a. cataracts
b. lens is a UV filter, absorbs all UVA plus UVB not picked up by cornea
3. most sunglasses block all but 1-2% of UVA

C. Tanning preparations
1. sunscreens
2. skin types - 6 of
3. effects of prolonged exposure to sunlight
a. decreased skin elasticity
b. increased aging and wrinkling
c. decreased immune system response
4. UV ray characteristics
a. not hot
b. not affected by clouds
c. not affected by thin clothing or water immersion

D. DOSAGE AND PROCEDURES
1. read UVL manual
2. warm, private, well ventilated (ozone) treatment area
3. 5 minute warmup of lamp with shutters closed
4. don't turn off lamp until completely done
5. goggles for patient and therapist
6. wash area prior to treatment
7. remove all clothing from treatment area
8. determine MED - minimal erythemal dose
a. SED - suberythemal dose
b. MED - erythema appears 1-6 hours, disappears within 24 hours
c. E1 - first degree erythemal dose
(1) erythema 1-3 days
(2) mild peeling
(3) 2 1/2 times MED dose
d. E2 - second degree erythemal dose
(1) intense erythema
(2) peeling and pigmentation
(3) 5 times MED
(4) for local treatment administer to no greater than 6 inches square
e. E3 - third degree erythemal dose
(1) erythema with severe blistering
(2) 10 times MED
(3) for local treatments administer to no greater than 2 inches square
f. hot quartz lamps - all bands, cold quartz - 90% in C band g. Laws(159-163 in Hayes)
(1) Grotthus Draper
(2) Inverse Square
(3) Cosine