CANS CANS Skincare & Dermatological Treatments 2 — Questions and Answers
Question 1: Which SPF rating is the minimum recommended by US dermatology guidelines for daily photoprotection in aesthetic patients?
- SPF 15
- SPF 30 (Correct answer)
- SPF 50
- SPF 70
Correct answer: SPF 30
The American Academy of Dermatology recommends a minimum of SPF 30 for broad-spectrum daily sun protection.
Question 2: What distinguishes physical (mineral) sunscreens from chemical sunscreens in mechanism of action?
- Physical sunscreens absorb UV and convert it to heat; chemical sunscreens reflect UV
- Physical sunscreens reflect and scatter UV; chemical sunscreens absorb UV and convert it to heat (Correct answer)
- Both reflect UV but at different wavelengths
- Chemical sunscreens are more photostable than physical sunscreens
Correct answer: Physical sunscreens reflect and scatter UV; chemical sunscreens absorb UV and convert it to heat
Mineral sunscreens (zinc oxide, titanium dioxide) sit on the skin surface and physically reflect/scatter UV radiation, while chemical filters absorb UV energy and dissipate it as heat.
Question 3: A patient develops a contact dermatitis reaction 48 hours after a new skincare product. This is most consistent with which type of hypersensitivity reaction?
- Type I (IgE-mediated)
- Type II (cytotoxic)
- Type IV (delayed-type / T-cell mediated) (Correct answer)
- Type III (immune complex)
Correct answer: Type IV (delayed-type / T-cell mediated)
A 48-hour delayed reaction to a topical agent is characteristic of Type IV delayed-type hypersensitivity, mediated by sensitized T-cells.
Question 4: Which skin condition is characterized by symmetric erythematous papules and pustules on the central face, often exacerbated by heat and spicy foods?
- Perioral dermatitis
- Seborrheic dermatitis
- Rosacea (Correct answer)
- Acne vulgaris
Correct answer: Rosacea
Rosacea presents with centrofacial erythema, papules, and pustules, and is commonly triggered by heat, spicy food, alcohol, and sun exposure.
Question 5: When performing microneedling, what depth setting is most appropriate for treating superficial fine lines and improving skin texture?
- 0.1–0.3 mm
- 0.5–1.5 mm (Correct answer)
- 2.0–2.5 mm
- 3.0 mm
Correct answer: 0.5–1.5 mm
A depth of 0.5–1.5 mm creates controlled micro-injuries in the dermis to stimulate collagen without significant downtime.
Question 6: Which topical anesthetic formulation is commonly applied before aesthetic procedures to reduce patient discomfort?
- Benzocaine 5% alone
- EMLA cream (lidocaine 2.5% + prilocaine 2.5%) (Correct answer)
- Tetracaine 10% alone
- Procaine 1% solution
Correct answer: EMLA cream (lidocaine 2.5% + prilocaine 2.5%)
EMLA cream combines lidocaine and prilocaine and is the most widely used topical anesthetic for pre-procedure skin numbing in aesthetics.
CANS CANS Skincare & Dermatological Treatments 2
Which SPF rating is the minimum recommended by US dermatology guidelines for daily photoprotection in aesthetic patients?