Dermatologist Certificate Dermatological Procedures and Treatments 2 — Questions and Answers
Question 1: What is the primary mechanism of action of botulinum toxin A in cosmetic dermatology?
- Inhibits acetylcholine release at the neuromuscular junction causing temporary muscle paralysis (Correct answer)
- Stimulates collagen production in the dermis
- Blocks substance P to reduce inflammation
- Disrupts disulfide bonds in keratin filaments
Correct answer: Inhibits acetylcholine release at the neuromuscular junction causing temporary muscle paralysis
Botulinum toxin A cleaves SNAP-25, preventing acetylcholine vesicle fusion at the neuromuscular junction, thereby causing temporary flaccid paralysis of injected muscles.
Question 2: Which filler material provides the longest duration of effect among commonly used dermal fillers?
- Poly-L-lactic acid (Sculptra) (Correct answer)
- Hyaluronic acid fillers
- Calcium hydroxylapatite (Radiesse)
- Collagen fillers
Correct answer: Poly-L-lactic acid (Sculptra)
Poly-L-lactic acid (Sculptra) is a biostimulatory filler that stimulates neocollagenesis over months, with results lasting up to 2 years or more.
Question 3: What is the purpose of patch testing in dermatology?
- To identify specific allergens causing allergic contact dermatitis (Correct answer)
- To diagnose irritant contact dermatitis
- To detect immediate IgE-mediated hypersensitivity reactions
- To confirm atopic dermatitis diagnosis
Correct answer: To identify specific allergens causing allergic contact dermatitis
Patch testing (epicutaneous testing) identifies specific causative allergens in type IV delayed hypersensitivity reactions responsible for allergic contact dermatitis.
Question 4: Which electrosurgical technique uses alternating current to destroy tissue while controlling hemostasis?
- Electrodesiccation and curettage (ED&C) (Correct answer)
- Radiofrequency ablation
- Electrolysis
- Iontophoresis
Correct answer: Electrodesiccation and curettage (ED&C)
Electrodesiccation and curettage uses high-frequency alternating current to dehydrate and destroy superficial tumor tissue, followed by physical removal with a curette.
Question 5: What is the correct depth of injection for hyaluronic acid filler used to treat nasolabial folds?
- Deep dermis to subcutaneous junction (Correct answer)
- Superficial epidermis
- Subperiosteal plane
- Muscle belly
Correct answer: Deep dermis to subcutaneous junction
Nasolabial fold correction with HA filler requires injection at the deep dermis to subcutaneous junction to provide volume support and lift without visibility of filler.
Question 6: Sentinel lymph node biopsy is recommended for melanomas with Breslow thickness greater than which measurement?
- 0.8 mm (or 0.8–1.0 mm with high-risk features) (Correct answer)
- 0.5 mm
- 2.0 mm
- 1.5 mm
Correct answer: 0.8 mm (or 0.8–1.0 mm with high-risk features)
Current NCCN guidelines recommend sentinel lymph node biopsy for melanomas >0.8 mm in Breslow thickness, or for thinner melanomas with ulceration or high mitotic rate.
Dermatologist Certificate Dermatological Procedures and Treatments 2
What is the primary mechanism of action of botulinum toxin A in cosmetic dermatology?