PANCE Dermatology 4 — Questions and Answers
Question 1: A 3-year-old presents with vesicles on an erythematous base in a dermatomal distribution on the trunk. The child's mother has active chickenpox. What is the most likely diagnosis?
- Herpes zoster (shingles)
- Primary varicella (chickenpox) (Correct answer)
- Hand-foot-mouth disease
- Eczema herpeticum
Correct answer: Primary varicella (chickenpox)
A young child exposed to varicella presenting with vesicles on an erythematous base is most consistent with primary varicella (chickenpox), not zoster (which requires prior VZV infection).
Question 2: A 45-year-old man with HIV (CD4 count 80 cells/μL) presents with painless, papular, violaceous lesions on his lower extremities and oral mucosa. What is the causative organism?
- Human herpesvirus 8 (HHV-8) (Correct answer)
- Epstein-Barr virus
- Cytomegalovirus
- Human papillomavirus
Correct answer: Human herpesvirus 8 (HHV-8)
Kaposi sarcoma in HIV-infected individuals is caused by HHV-8 (KSHV) and presents as violaceous vascular tumors, particularly at low CD4 counts.
Question 3: A 16-year-old girl presents with pruritic vesicles on her fingers, palms, and soles that seem to 'taper' deep into the skin. The condition worsens in summer. What is the diagnosis?
- Contact dermatitis
- Dyshidrotic eczema (pompholyx) (Correct answer)
- Tinea pedis
- Scabies
Correct answer: Dyshidrotic eczema (pompholyx)
Dyshidrotic eczema (pompholyx) presents with intensely pruritic, deep-seated vesicles on the palms, soles, and lateral fingers, often triggered by heat and sweating.
Question 4: A 68-year-old woman presents with tense bullae on an erythematous base on her trunk and proximal extremities. Direct immunofluorescence shows linear IgG and C3 at the dermal-epidermal junction. What is the diagnosis?
- Pemphigus vulgaris
- Bullous pemphigoid (Correct answer)
- Dermatitis herpetiformis
- Linear IgA bullous dermatosis
Correct answer: Bullous pemphigoid
Bullous pemphigoid features tense bullae (not flaccid), linear IgG/C3 at the BMZ on DIF, and anti-BP180/BP230 antibodies targeting hemidesmosomes.
Question 5: A 55-year-old man presents with red, scaling patches in the groin and axillae with central clearing. KOH preparation is positive for branching hyphae. What is the most appropriate treatment?
- Topical clotrimazole (Correct answer)
- Oral griseofulvin
- Topical mupirocin
- Oral doxycycline
Correct answer: Topical clotrimazole
Tinea cruris (dermatophyte infection of the groin) is treated with topical antifungals such as clotrimazole or terbinafine; oral therapy is reserved for resistant or extensive cases.
Question 6: A newborn develops erythematous macules and papules with surrounding flares on the trunk and extremities within 24–48 hours of birth. Wright stain of pustule contents shows eosinophils. What is the diagnosis?
- Neonatal herpes simplex
- Erythema toxicum neonatorum (Correct answer)
- Transient neonatal pustular melanosis
- Miliaria rubra
Correct answer: Erythema toxicum neonatorum
Erythema toxicum neonatorum is a benign, self-limiting rash in newborns characterized by eosinophil-filled pustules on Wright stain, requiring no treatment.
Question 7: A 40-year-old man presents with recurrent painful oral aphthous ulcers, genital ulcerations, and uveitis. Which additional finding would confirm the diagnosis of Behçet disease?
- Positive ANA titer
- Positive pathergy test (Correct answer)
- HLA-B27 positivity
- Anti-dsDNA antibodies
Correct answer: Positive pathergy test
A positive pathergy test (formation of a papule or pustule after minor skin injury) supports the diagnosis of Behçet disease along with oral/genital ulcers and uveitis.
PANCE Dermatology 4
A 3-year-old presents with vesicles on an erythematous base in a dermatomal distribution on the trunk.
The child's mother has active chickenpox.
What is the most likely diagnosis?