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Ultraviolet Therapy

Jennifer L. Doherty-Restrepo, MS, ATC, LAT

Entry-Level Master Athletic TrainingEducation Program

PET 4995: Therapeutic Modalities

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Ultraviolet Radiation (UVR) Electromagnetic spectrum (2000 to

4000 ) Divided into three ranges:

UV-A = Near UV (3200 to 4000 ) Little or no physiologic effect

UV-B = Middle UV (2900 to 3200 ) Sunburn and age-related skin changes

UV-C = Far UV (2000 to 2900 )

Bactericidal

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Ultraviolet Radiation Most likely to be used

UV-B or UV-C

UVR depth of penetration is 1 to 2 mm Physiologic effects are superficial Used to treat various skin disorders

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Effect on Cells UVR causes chemical excitation of cells Results in alteration of cell biochemistry

and cellular metabolism Affects synthesis of DNA and RNA

Protein and enzyme production isaltered, which may result in cell death

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Effects on Skin Epidermis

Keratinocytes, whichprovide fibrous protective

protein of skin Dermis

Papillary layer - rich bloodsupply

Reticular layer - heavyconnective tissue containingfibroblasts, histocytes, andmast cells

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Effects on Skin: Erythema Generalized response to UVR exposure

Reddening of skin

Acute inflammatory reaction End results:

Erythema- sunburn Pigmentation - tanning Increased epidermal thickness

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Effects on Skin:

Photosensitization Process in which a person becomes

overly sensitive to UVR Acute effects of UVR exposure may be

exacerbated if certain chemicals ormedications are present on skin (or in

body)

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Effects on Skin: Tanning Increase of pigmentation

Protective mechanism activated by UVR exposure

Increase of melanin Pigment responsible for darkening skin

Melanin functions as a biologic filter of

UVR By scattering radiation By absorbing UVR By dissipating absorbed energy as heat

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Effects on Skin: Tanning Artificial Tanning - manufacturers claim

tanning beds produce only UV-A Production of UV-A is largely

unregulated Effects of long-term exposure to UV-A

are unknown

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Effects on Skin: Long-term Premature aging of the skin Dryness, cracking, and decreased elasticity

Linked to UVR-induced DNA damage Skin cancer

Most common malignant tumor found in humans Basal cell carcinoma (rarely metastasizes) Squamous cell carcinoma (metastasizes in 5%) Malignant melanoma (usually metastasizes)

Damage to DNA suspected as cause Rate of cure exceeds 95% with early detection

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Effects on Eyes UVR exposure causes acute inflammation

called photokeratitis Delayed reaction, occurs within 6 - 24 hours Signs/Symptoms:

Conjunctivitis accompanied by erythema ofadjacent facial skin

Sensation of a foreign body on eye

Photophobia Increased tear production Spasm of the ocular muscles

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Systemic Effects Photosynthesis of vitamin D

Following exposure to UVR in UV-B range

May be used to treat Ca++ andphosphorus disorders Rickets and tetany

Treatment of choice; however, is dietarysupplementation

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Ultraviolet Generators Carbon arc lamp

Xenon compact arc lamp

Fluorescent ultraviolet lamp (black light)

Mercury arc lamp

Most commonly used in sports medicine

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Mercury Arc Lamp Mercury contained in a quartz envelope

Heavy metal in a liquid state

At 8000C, mercury atoms vaporize andbecome incandescent

Emit ultraviolet, infrared, and visible

light

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Mercury Arc Lamp High-pressure lamp = Hot lamp UVR produced falls within UV-B range Mainly used to produce erythema and

accompanying photochemical reactions

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Mercury Arc Lamp

Low-pressure = Cold lamp UVR between 1849 - 2537 Does not require warm-up or cool-down Used mainly for bactericidal effect

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Mercury Arc Lamp

Positioning Apply cosine law and inverse square law

Distance of lamp must be kept constantif intensity of treatments is to be equal

Standardized at each clinic Usually ranges between 24 - 40 inches

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Techniques of Application

Minimal Erythemal Dose (MED) Exposure time needed to produce a faint

erythema of the skin 24 hours afterexposure

Question patient regarding

photosensitizing drugs

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Minimal Erythemal Dose

Patient draped only exposing test site

Height of lamp adjusted to same level as Tx Paper with five cutouts (1 square) 1 apartplaced over test site

Shutters are opened and cutouts exposed at

15-sec intervals

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Visual inspection after 24 hours to determineMED No erythema = suberythemal dose

Erythema still present at 48 hours 1st degree erythemal dose (2.5 times MED)

Erythema persists from 48-72 hours

2nd degree erythemal dose (5 times MED) Erythema lasting past 72 hours

3rd degree erythemal dose

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Skin adapts to UVR exposure,therefore, MED will gradually increase

with repeated treatments Must gradually increase exposure time

to achieve the same reaction Increased by 5 seconds per treatment

Height of lamp remains constant

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Clinical Applications

Dermatologic conditions Psoriasis, acne, and hard to cure infectious

skin conditions such as pressure sores

Development of oral and topical

medications has greatly reduced theuse of ultraviolet

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Indications

Acne Aseptic wounds

Folliculitis Pityriasis rosea Tinea capitum Septic wounds Sinusitis Psoriasis

Pressure sores Osteomalacia

Diagnosis of skindisorders Increased vitamin D

production Sterilization Tanning Hyperplasia

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Contraindications

Porphyrias Pellagra

Lupus erythematosus Sarcoidosis Xeroderma

pigmentosum

Acute psoriasis Acute eczema Herpes simplex

Renal and hepaticinsufficiencies

Diabetes Hyperthyroidism Generalized dermatitis Advanced

arteriosclerosis Active and progressive

pulmonary tuberculosis

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Chapter 15_PET 4995(2)