Ultraviolet

1
Ultraviolet

• Veronica Southard PT MS GCS

2
Wavelengths

• All of UV 180.-gt 4000 nm
• Near UV 290nm? 400nm ( we use this)
• Far UV 180nm-gt290nm (autoclave)
• Wavelength determines penetration
• UV is absorbed from .22mm-gt1mm

3
Physiologic effects of UV

• CHEMICAL EFFECTS
• Vasodilation without erythema
• Increased production of steroids
• Sedative to nerve endings
• Increased metabolism
• Increased resistance to infection 2ary to inc
  antibody production
• Sterilization
• Psychological
• Vitamin D formation

4
Characteristics of UV

• Delayed erythema lasting several days
• Continued exposure causes damage to superficial
  cells thickening the epidermis.
• Peeling of the epidermis occurs which is called
  desquamation
• Pigmentation occurs with absorption in the deeper
  epidermis which initiates increased melanin
  production

5
Indications UV

• Dermatologic conditions I.e. psoriasis
• Ca, Phosphorus diseases
• Local ulcerations- bedsores, ulcers

6
Contraindications

• Photosensitivity
• Porphyrias (rare metabolic disorder)
• Pellegra dermatitis unable to absorb Niacin
• Skin cancer
• Albino
• Pulmonary TB
• Severe Cardiac, liver, kidney disease
• SLE Sarcoidosis, Xeroderma pigmentosum

• Photosensitizing drugs
• Acute skin irritation
• Pregnancy
• Radiation therapy sites
• Acute DM
• hyperthryoidism

7
Precautions

• Pt wears goggles
• PT wears goggles
• Time the RX to the second!
• All other areas of the pts body are covered

8
Determining the Erythemal dose

• A. Suberythemal dose (SED) no reax
• B. Minimal erythemal dose (MED) sl reddening
  noted 1-6 hours later, gone in 24 hours
• C. 1 MED !st degree, like a sunburn occurs 4-6
  hours lasts 2 days. May leave some pigmentation.
  Used over lt20 body surface

9
Erythemal dose cont

• D. 2 ED 2nd degree. More intense reax. Pt has
  reddening 3-4 hours after exposure. Slight
  swelling, peeling occurs. Takes 3 days to
  subside. Inc. pigmentation. Moderate sunburn.
  Tx areas lt 250cm2
• E. 3ED third degree. Destructive, intense
  reddening after 2 hours. Swelling, blisters,
  lasts 1 week. Painful. Smaller areas lt25cm2

10
Administering Erythemal doses

• Sub ED ½ MED
• 1 ED 21/2 x MED
• 2ED 5 x MED
• 3ED 10 x MED
• The stronger the dose the smaller the area

11
Determining the MED

• Fabricate an Erythometer
• Radiate each spot 15 seconds
• Wear goggles, cover pt.
• Lamp 30 away
• Reexamine skin every 2 hours
• MED is the shortest dose which causes reddening
  in 1-6 hours and disappears in 24

12
Life isnt this simple!

• If no response is achieved, retest at higher
  doses
• If all show up and last greater than 24 hours,
  retest with shorter doses.
• Tx dose is based on MED, with continued
  application, the time increases to repeat dose.
  This is secondary to thickening of the epidermis
  and increased pigmentation

13
Repeating the dosage

• To repeat
• MED add 25 more time to previous dose
• 1 ED add 50 more time
• 2 ED add 75
• 3 ED add 100 (double the time)
• For example to repeat a 1ED tx of 30 second, pts
  new time is 45 sec
• Max treatment time usually 2 minutes

14
Repeating the dose- after reaching 3 minutes

• Formula
• NEW DOSE
• OLD DOSE TIME X NEWDISTANCE 2
• --------------------------------------------------
  --- OLD DISTANCE 2
• Generally, if distance is lt24-30 dec. dose
• gt30 inches, increase dose

15
General body exposure

• Separate the body into 4 quadrants
• Ant upper body
• Ant lower body
• Post upper body
• Post lower body

16
Local application of UV

• Wound healing, uses a spot quartz or Kromeyer
  lamp which is commonly called Cold Quartz
• Hold lamp 1-6 from area
• MED is different
• MED is 12-15 sec
• 1 ED is 36-45 sec
• 2ED is 72-90 sec
• 3 ED is 135-180 sec

17
PUVA( photosensitization technique of UV in the
3600 A A band

• Pt drinks photosensitizaing agent (Psoratin)
• Enhances absorption
• Good for Psoriasis
• 10-15 sec UV

18
Frequency of Treatment

• SED DAILY
• MED ALTERNATING DAYS
• 1ED BIW
• 2ED 2 WEEKS APART
• 3 ED ONLY VERY LOCAL AREAS NOT FREQUENTLY GIVEN