Dermatologist Certificate General 5 — Questions and Answers
Question 1: What is the Breslow thickness threshold above which sentinel lymph node biopsy is routinely recommended for melanoma?
- 0.5 mm
- 0.8 mm
- 1.0 mm (Correct answer)
- 1.5 mm
Correct answer: 1.0 mm
SLNB is routinely recommended for melanomas >1.0 mm Breslow thickness; it may be considered for 0.8–1.0 mm lesions with high-risk features.
Question 2: A patient presents with diffuse hair shedding 3 months after a major surgery. What type of alopecia is this?
- Androgenetic alopecia
- Alopecia areata
- Telogen effluvium (Correct answer)
- Anagen effluvium
Correct answer: Telogen effluvium
Telogen effluvium occurs 2–4 months after a physiological stressor (surgery, illness, childbirth), causing premature shift of hair follicles into the telogen phase.
Question 3: Which condition is characterized by thickened, yellow-green nails with slow growth and is associated with lymphedema and pleural effusion?
- Onychomycosis
- Yellow nail syndrome (Correct answer)
- Pachyonychia congenita
- Nail-patella syndrome
Correct answer: Yellow nail syndrome
Yellow nail syndrome is a rare disorder characterized by yellow, thickened, slow-growing nails associated with lymphedema and respiratory manifestations.
Question 4: Photosensitivity caused by tetracyclines is primarily classified as which type of reaction?
- Phototoxic (Correct answer)
- Photoallergic
- Polymorphous light eruption
- Chronic actinic dermatitis
Correct answer: Phototoxic
Tetracyclines cause phototoxic reactions that are dose-dependent and do not require prior sensitization, occurring in most exposed individuals.
Question 5: Which type of hypersensitivity reaction is responsible for allergic contact dermatitis?
- Type I (IgE-mediated)
- Type II (cytotoxic)
- Type III (immune complex)
- Type IV (cell-mediated) (Correct answer)
Correct answer: Type IV (cell-mediated)
Allergic contact dermatitis is a Type IV delayed hypersensitivity reaction mediated by sensitized T lymphocytes, typically occurring 48–72 hours after exposure.
Question 6: A neonate develops a widespread vesiculopustular eruption within the first 2 weeks of life. Tzanck smear shows multinucleated giant cells. What is the diagnosis?
- Neonatal candidiasis
- Erythema toxicum neonatorum
- Neonatal herpes simplex (Correct answer)
- Transient neonatal pustular melanosis
Correct answer: Neonatal herpes simplex
Neonatal HSV presents with vesiculopustular eruption in the first weeks of life; Tzanck smear showing multinucleated giant cells confirms herpetic etiology.
Question 7: Which SPF value indicates protection against approximately 97% of UVB radiation?
- SPF 15
- SPF 30 (Correct answer)
- SPF 50
- SPF 100
Correct answer: SPF 30
SPF 30 blocks approximately 97% of UVB rays, SPF 50 blocks ~98%, and SPF 100 blocks ~99% — the incremental difference above SPF 30 is minimal.
Dermatologist Certificate General 5
What is the Breslow thickness threshold above which sentinel lymph node biopsy is routinely recommended for melanoma?