CDT CDT Phototherapy & Light-Based Treatments

Question 1

What wavelength range is used in narrowband UVB phototherapy?

Accepted Answer

UVB at 311–313 nm

Answer

Narrowband UVB phototherapy uses the 311–313 nm wavelength range, which is most effective for psoriasis, vitiligo, and atopic dermatitis.

Question 2

Which condition is narrowband UVB phototherapy most commonly used to treat?

Accepted Answer

Psoriasis

Answer

Narrowband UVB is most commonly used for psoriasis, and is also effective for vitiligo and atopic dermatitis.

Question 3

What does PUVA phototherapy combine?

Accepted Answer

Psoralen + UVA light

Answer

PUVA combines a psoralen photosensitizer (oral or topical) with UVA light exposure to treat psoriasis, vitiligo, and cutaneous T-cell lymphoma.

Question 4

What is the Minimal Erythema Dose (MED) used to determine in phototherapy?

Accepted Answer

Safe starting UV dose for treatment

Answer

The MED is the lowest UV dose producing minimal redness at 24 hours, used to calculate a safe and individualized starting phototherapy dose.

Question 5

Which protective measure is mandatory during and after PUVA therapy?

Accepted Answer

UV-protective goggles during and for 24 hours after treatment

Answer

UV-protective goggles must be worn during PUVA and for 24 hours after because psoralen sensitizes the eyes to UV-induced damage.

(CDT) Certified Dermatology Tech Practice Test