CLS Photofacial and Skin Rejuvenation 2

Question 1

Which chromophore is targeted when IPL is used to treat facial telangiectasias (broken capillaries)?

Accepted Answer

Oxyhemoglobin in the superficial vessels

Answer

Oxyhemoglobin has strong absorption peaks at 418 nm, 542 nm, and 577 nm. IPL with a 560 nm or 590 nm cut-off filter delivers energy preferentially absorbed by oxyhemoglobin in superficial telangiectasias, heating and coagulating the vessel wall without damaging surrounding tissue.

Question 2

What is the clinical significance of Fitzpatrick skin type classification when planning a photofacial treatment?

Accepted Answer

It guides wavelength/filter selection, fluence, and cooling intensity to minimize risk of dyspigmentation in darker skin

Answer

Higher Fitzpatrick types (IV–VI) have more epidermal melanin competing with the target chromophore. This increases the risk of epidermal overheating, burns, and post-inflammatory hyperpigmentation. Parameters must be adjusted (longer wavelength filters, lower fluences, more aggressive cooling) to safely treat darker skin types.

Question 3

Following ablative CO₂ laser resurfacing, a patient develops diffuse erythema and pruritus for three weeks. What is the expected course?

Accepted Answer

Persistent erythema and pruritus for 2–6 weeks is a normal part of post-ablative healing and re-epithelialization

Answer

Post-ablative erythema and pruritus are normal components of the wound healing and re-epithelialization process. Erythema typically persists 2–4 weeks after mild ablative treatments and up to 3–6 months after deep resurfacing, as new collagen forms and the dermis remodels. Patients should be counseled about this expected course.

Question 4

Er:YAG (Erbium:YAG) laser at 2940 nm versus CO₂ laser at 10,600 nm for skin resurfacing — which statement best differentiates them?

Accepted Answer

Er:YAG ablates with minimal thermal damage due to higher water absorption; CO₂ causes more residual thermal coagulation, promoting hemostasis and collagen stimulation

Answer

Er:YAG at 2940 nm has ~16× greater water absorption than CO₂, resulting in highly precise ablation with minimal residual thermal damage. CO₂ has greater residual thermal coagulation (~100 µm), which provides better hemostasis and deeper collagen stimulation but more downtime. Er:YAG is preferred for precise, shallower resurfacing with less downtime.

Question 5

What is the purpose of applying a broad-spectrum SPF 30+ sunscreen daily for 4–6 weeks before and after an IPL photofacial?

Accepted Answer

UV exposure increases epidermal melanin, raising the risk of hyperpigmentation and reducing treatment efficacy and safety

Answer

UV-induced melanin production before treatment increases the epidermal melanin load, reducing the contrast between the pigmented target and the epidermis and increasing the risk of epidermal burns and PIH. Post-treatment, photosensitive healing skin is highly susceptible to UV-triggered PIH, making consistent SPF use essential.

CLS - Certified Laser Specialist Practice Test

CLS - Certified Laser Specialist Practice Test

CLS Photofacial and Skin Rejuvenation 2