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DPT 623 Physical Agents > UV Radiation > Flashcards

Flashcards in UV Radiation Deck (42)
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True/False. Psoriasis is most responsive to UVA alone.

False. Psoriasis is most responsive to UVA in conjunction with oral or topical psoralen, which makes the body more sensitive to the radiation. UVA in conjunction with the oral or topical psoralen is termed PUVA.


The frequency of UV radiation lies between that of what?

It lies between that of x-rays and visible light


UV radiation is divided into three bands. What are they?

UVA (wavelengths of 320 - 400), UVB (wavelengths of 290 - 320), and UVC (wavelengths less than 290)


UVA is also known as what?

Long-wave UV, and it produces fluorescence in many substances


UVB is also known as what?

Middle-wave UV, and it produces the most erythema


UVC is also known as what?

Short-wave UV, and it is germicidal


The depth of UV radiation is affected by what?

The intensity of radiation reaching the skin, the wavelength and power of the radiation source, the size of the area being treated, the thickness and pigmentation of the skin, and the duration of treatment


What is erythema?

Redness of the skin as a result of dilation of the superficial blood vessels caused by the release of histamines. It is one of the most common and obvious effects of exposure to UV radiation.


What is MED?

MED (minimal erythemal dose) is determined for each patient before initiating treatment with UV radiation


What are some side effects of PUVA treatment?

Epidermal pigmentation and hyperplasia, immune suppression, and the release of free radicals


True or False: UV irradiation of the skin is necessary for the conversion of ingested provitamin D to active vitamin D?

True: Because vitamin D controls calcium absorption and exchange, it is an essential vitamin for bone formation, it also influences brain, kidney, intestine, endocrine, immune, and cellular function.


In the laboratory setting, can UVC radiation be bactericidal?

Yes, UVC radiation is used to kill bacteria in food and in one small study, UVC was found to be as effective as standard hospital cleaners in removing pathogens from hospital surfaces.


A chronic inflammatory skin disease that appears to be based on genetic predisposition.



What is the science behind topical psoralen?

It reduces the appearance of psoriatic plaques by interfering with cell replication and preventing the excessive cell proliferation that causes psoriasis.


What is the frequency band of UV for the use of wound healing?



How is UV radiation thought to contribute to wound healing?

The UVC radiation increases epithelial cell turnover, accelerates granulation tissue formation, increases blood flow, kills bacteria, increases Vitamin D production, and promotes sloughing of necrotic tissue.


What are the contraindications for the use of UV radiation?

Irradiation of the eyes, skin cancer, pulmonary tuberculosis, cardiac, kidney, or liver disease, systemic lupus erythematosus, fever


What are the precautions for the use of UV radiation?

Photosensitizing medications and dietary supplements, photosensitivity, recent x-ray therapy, recent UV radiation


What are some examples of photosensitizing medications?

Sulfonamide, tetracycline, and quinolone antibiotics; gold-based medications used for the treatment of RA; phenothiazines used for the treatment of anxiety and psychosis; and psoralens used for the treatment of psoriasis


Why are those with fair skin and red hair more sensitive to UV radiation?

These individuals have an accelerated and exaggerated skin response to UV radiation.


What are some side effects of PUVA treatment?

Epidermal pigmentation and hyperplasia, immune suppression, and the release of free radicals


Chronic exposure to UV radiation, including sunlight, is associated with premature aging of the skin is known as what?

Actinic damage


True or False: UV phototherapy has the same level of risk of producing cutaneous cancers as sunlight.

False: UV phototherapy has a low risk of producing cutaneous cancer, except possibly for the skin at the male genitals.


An inflammation of the cornea that can be extremely painful that usually appears about 6-12 hours after UV exposure and resolves within 2 days is a symptom of what?



An inflammation of the insides of the eyelids and the membrane that covers the cornea, results in a sensation of gritty eyes and varying degrees of photophobia, tearing, and blepharospasm is a symptom of what?



Chronic UVA and UVB exposures have been associated with the development of what?



What can affect a person's sensitivity to UV radiation?

Skin pigmentation, age, prior exposure to UV radiation, the type of UV, and use of sensitizing medications.


True or False: The same lamp used to test the patient's skin for sensitivity must be used for every subsequent treatment.

True: because UV radiation can vary significantly with even slightly different frequencies of radiation, which could cause adverse reactions to the treatment.


The UV dose grade where there is no change in skin redness occurring in the 24 hours after UV exposure is what?

Suberythemal dose (SED)


What is the UV dose grade when the erythema has severe blistering, peeling, and exudation.

Third-degree erythema