CLT Skin Conditions & Pathology for Light Therapy 1 — Questions and Answers
Question 1: Which skin condition is characterized by accelerated keratinocyte proliferation, silver-white plaques, and is commonly treated with narrowband UVB light therapy?
- Psoriasis (Correct answer)
- Rosacea
- Eczema
- Vitiligo
Correct answer: Psoriasis
Psoriasis involves rapid skin cell turnover producing thick plaques, and narrowband UVB phototherapy is an evidence-based treatment that slows this proliferation.
Question 2: What is vitiligo, and which light therapy approach is used to treat it?
- Loss of melanocytes causing depigmented patches, treated with narrowband UVB or excimer laser (Correct answer)
- Excess melanin deposition causing dark spots, treated with IPL
- Chronic inflammation causing redness, treated with red LED light
- Fungal infection causing discoloration, treated with blue light
Correct answer: Loss of melanocytes causing depigmented patches, treated with narrowband UVB or excimer laser
Vitiligo results from melanocyte destruction, and narrowband UVB or targeted excimer laser can stimulate repigmentation by activating residual melanocyte precursors.
Question 3: Seasonal Affective Disorder (SAD) is primarily treated with which type of light therapy?
- Bright white light (10,000 lux) exposure in the morning (Correct answer)
- Red LED light applied to the scalp
- Near-infrared panels directed at the chest
- Blue laser therapy to pressure points
Correct answer: Bright white light (10,000 lux) exposure in the morning
SAD light therapy uses a 10,000-lux bright white light box delivered in the morning to reset circadian rhythms and improve mood in winter months.
Question 4: Which skin type, according to the Fitzpatrick Scale, carries the highest risk of UV-induced hyperpigmentation and requires the most conservative light therapy dosing?
- Fitzpatrick Types V and VI (brown to dark brown/black skin) (Correct answer)
- Fitzpatrick Type I (very fair skin)
- Fitzpatrick Type III (medium skin)
- Fitzpatrick Type II (fair skin)
Correct answer: Fitzpatrick Types V and VI (brown to dark brown/black skin)
Darker Fitzpatrick skin types (V–VI) have higher melanin density and are more prone to post-inflammatory hyperpigmentation from aggressive light exposure.
Question 5: What is actinic keratosis, and why is it significant for a CLT planning light therapy?
- A pre-cancerous UV-damaged lesion that may contraindicate certain light therapies and requires physician evaluation (Correct answer)
- A benign sunspot that is safely treated with high-intensity red light
- A bacterial infection of hair follicles that responds to blue light therapy
- A fungal overgrowth treated with broad-spectrum phototherapy
Correct answer: A pre-cancerous UV-damaged lesion that may contraindicate certain light therapies and requires physician evaluation
Actinic keratoses are pre-malignant lesions caused by UV damage, and applying additional light therapy to these areas requires physician clearance to avoid promoting progression.
Question 6: Rosacea subtypes most likely to benefit from light therapy include which of the following?
- Erythematotelangiectatic rosacea (persistent redness and visible vessels) (Correct answer)
- Ocular rosacea affecting the eyelids
- Phymatous rosacea causing skin thickening
- All rosacea subtypes respond equally to all light modalities
Correct answer: Erythematotelangiectatic rosacea (persistent redness and visible vessels)
IPL and vascular lasers that target oxyhemoglobin are most effective for erythematotelangiectatic rosacea presenting with facial redness and broken capillaries.
CLT Skin Conditions & Pathology for Light Therapy 1
Which skin condition is characterized by accelerated keratinocyte proliferation, silver-white plaques, and is commonly treated with narrowband UVB light therapy?