CDT Common Skin Conditions & Treatment 2 — Questions and Answers
Question 1: A patient presents with sharply demarcated, silvery-scaled plaques on the elbows and knees. Which pathophysiological mechanism is primarily responsible for this condition?
- Excessive melanin production
- Accelerated keratinocyte proliferation (Correct answer)
- Autoimmune destruction of melanocytes
- Sebaceous gland hyperplasia
Correct answer: Accelerated keratinocyte proliferation
Psoriasis is characterized by accelerated keratinocyte proliferation, causing rapid skin cell turnover that leads to the classic silvery scales.
Question 2: Which topical treatment is considered first-line for mild-to-moderate atopic dermatitis in adults?
- Topical retinoids
- Topical corticosteroids (Correct answer)
- Topical antibiotics
- Topical antifungals
Correct answer: Topical corticosteroids
Topical corticosteroids are the mainstay first-line treatment for atopic dermatitis due to their anti-inflammatory effects.
Question 3: A patient with rosacea is most likely to report worsening symptoms after which trigger?
- Cold weather exposure
- Drinking ice water
- Spicy food consumption (Correct answer)
- Sleeping in a cool room
Correct answer: Spicy food consumption
Spicy foods are a common trigger for rosacea flares because they induce facial flushing and vasodilation.
Question 4: Tinea versicolor is caused by which organism?
- Trichophyton rubrum
- Malassezia furfur (Correct answer)
- Candida albicans
- Microsporum canis
Correct answer: Malassezia furfur
Tinea versicolor is caused by Malassezia furfur, a lipophilic yeast that is part of normal skin flora.
Question 5: Which finding on dermoscopy is most characteristic of a benign seborrheic keratosis?
- Atypical pigment network
- Comedo-like openings and milia-like cysts (Correct answer)
- Irregular streaks
- Blue-white veil
Correct answer: Comedo-like openings and milia-like cysts
Comedo-like openings (pseudofollicular openings) and milia-like cysts are the hallmark dermoscopic features of seborrheic keratosis.
Question 6: A child presents with honey-colored crusts around the nose and mouth. What is the most likely diagnosis?
- Eczema herpeticum
- Impetigo (Correct answer)
- Perioral dermatitis
- Angular cheilitis
Correct answer: Impetigo
Impetigo classically presents with honey-colored (golden) crusts, most commonly around the nose and mouth in children.
Question 7: Which treatment modality uses focused ultraviolet B light to treat localized skin conditions like psoriasis and vitiligo?
- PUVA therapy
- Narrowband UVB phototherapy
- Excimer laser therapy (Correct answer)
- IPL (intense pulsed light)
Correct answer: Excimer laser therapy
The excimer laser delivers a focused 308-nm UVB beam, allowing targeted treatment of localized plaques without irradiating surrounding healthy skin.
CDT Common Skin Conditions & Treatment 2
A patient presents with sharply demarcated, silvery-scaled plaques on the elbows and knees.
Which pathophysiological mechanism is primarily responsible for this condition?