CLT Hair Removal Laser Procedures 2 — Questions and Answers
Question 1: Which laser wavelength is considered the gold standard for hair removal in patients with darker skin tones (Fitzpatrick IV-VI)?
- 755 nm Alexandrite
- 694 nm Ruby
- 1064 nm Nd:YAG (Correct answer)
- 810 nm Diode
Correct answer: 1064 nm Nd:YAG
The 1064 nm Nd:YAG laser is preferred for darker skin types because its longer wavelength penetrates deeper and is less absorbed by epidermal melanin, reducing burn risk.
Question 2: A patient reports that their treated hair is still shedding two weeks after a laser hair removal session. What is the correct response?
- This indicates treatment failure and re-treatment is needed immediately
- This is a normal post-treatment process called exfoliation of treated follicles (Correct answer)
- The laser setting was too low and must be increased at the next visit
- The patient should stop using any moisturizers to speed shedding
Correct answer: This is a normal post-treatment process called exfoliation of treated follicles
Shedding of treated hairs 1–3 weeks post-treatment is a normal and expected sign that the follicles were successfully targeted.
Question 3: What is the primary reason treatment intervals for laser hair removal are spaced 4–8 weeks apart for the face and 8–12 weeks for the body?
- To allow the laser equipment to be recalibrated between sessions
- To match the anagen (active growth) phase cycle of hair in different body regions (Correct answer)
- To give the patient time to avoid sun exposure before each session
- To reduce the cost of multiple sessions for the patient
Correct answer: To match the anagen (active growth) phase cycle of hair in different body regions
Laser hair removal is only effective during the anagen phase, and hair cycles vary by location, requiring treatment intervals aligned with regional growth cycles.
Question 4: Which cooling method is integrated directly into the handpiece tip to protect the epidermis during laser hair removal?
- Cryogen spray cooling
- Contact cooling (sapphire tip) (Correct answer)
- Air cooling (zimmer chiller)
- Ice pack application
Correct answer: Contact cooling (sapphire tip)
Contact cooling via a sapphire-tipped handpiece cools the skin surface immediately before and during laser pulse delivery to protect the epidermis.
Question 5: A patient with a Fitzpatrick skin type III wants laser hair removal on their upper lip. Which parameter adjustment is most appropriate compared to treating the same area on a type I patient?
- Increase fluence and decrease pulse duration
- Decrease fluence and increase pulse duration (Correct answer)
- Increase fluence and spot size simultaneously
- No parameter change is needed for minor skin type differences
Correct answer: Decrease fluence and increase pulse duration
Darker skin types require lower fluence and longer pulse durations to reduce epidermal heating while still targeting the hair follicle safely.
Question 6: What term describes the concept that laser energy must be delivered faster than the target tissue can cool down to achieve selective destruction?
- Selective photothermolysis
- Thermal relaxation time (Correct answer)
- Photomechanical disruption
- Chromophore absorption
Correct answer: Thermal relaxation time
Thermal relaxation time (TRT) is the time it takes a target to lose half its heat; pulse duration must be shorter than the TRT of the follicle for selective damage.
Question 7: Which condition is an absolute contraindication for laser hair removal?
- Mild seasonal allergies
- Active herpes simplex infection in the treatment area (Correct answer)
- Light tan from indirect sun exposure
- Use of non-photosensitizing antihistamines
Correct answer: Active herpes simplex infection in the treatment area
Active herpes simplex lesions in the treatment area are an absolute contraindication because laser treatment can spread the infection and cause severe outbreaks.
CLT Hair Removal Laser Procedures 2
Which laser wavelength is considered the gold standard for hair removal in patients with darker skin tones (Fitzpatrick IV-VI)?