Aesthetic Dermatology MCQ - Skin tightening

A 55-year-old woman with Fitzpatrick skin type II presents with mild to moderate skin laxity in the lower face and neck. She seeks a non-surgical treatment with minimal downtime. Which of the following devices uses monopolar radiofrequency to heat the deep dermis and subcutaneous tissue, stimulating collagen contraction and neocollagenesis, and requires active cooling to protect the epidermis?

A) Monopolar radiofrequency (e.g., Thermage)
B) Fractional carbon dioxide laser
C) Intense pulsed light (IPL)
D) Ultrasound (e.g., Ultherapy)
E) Bipolar radiofrequency with light source (e.g., IPL/RF combination)

Correct Answer: A) Monopolar radiofrequency (e.g., Thermage)

Explanation

This question addresses non-surgical skin tightening technologies, specifically focusing on radiofrequency (RF) devices.

Key Features of Monopolar Radiofrequency (e.g., Thermage):

• Mechanism: Monopolar RF delivers high-frequency electrical currents that generate heat as they pass through the skin's resistance. The energy penetrates deeply into the dermis and subcutaneous tissue.

• Target: The heat causes immediate collagen contraction and denaturation, followed by a wound healing response that stimulates long-term neocollagenesis over several months.

• Epidermal Protection: These systems incorporate integrated cryogen cooling to protect the epidermis from overheating and injury, allowing energy to be delivered safely to deeper layers.

• Indications: Mild to moderate skin laxity in the face, neck, and body.

• Downtime: Minimal to none; patients may experience transient erythema and edema.

Why Not the Other Options?

• (B) Fractional carbon dioxide laser: An ablative laser that targets water, causing controlled tissue vaporization for resurfacing. It is not primarily a skin tightening device and requires significant downtime.

• (C) Intense pulsed light (IPL): A broadband light source used for pigmentation and vascular lesions. It does not deliver focused RF energy for deep heating and skin tightening.

• (D) Ultrasound (e.g., Ultherapy): Uses focused ultrasound (not radiofrequency) to generate thermal coagulation points at specific depths (e.g., SMAS layer). It does not require active cooling for epidermal protection in the same way.

• (E) Bipolar radiofrequency with light source: Bipolar RF has a limited depth of penetration as the current flows between two closely spaced electrodes. While often combined with light sources for superficial effects, it is not as effective for deep dermal heating as monopolar RF.

Management Considerations:

• Patient Selection: Best for patients with mild to moderate laxity and good skin elasticity.

• Technique: Multiple passes at appropriate energy levels are crucial for efficacy.

• Results: Gradual improvement over 3-6 months as new collagen forms.

Prognosis:
Moderate improvement in skin tightness and texture. Multiple treatments may be needed for optimal results. It is not a substitute for surgical rhytidectomy in cases of severe laxity.

Note: Monopolar RF is a cornerstone of non-surgical skin tightening. The key differentiator is its deep thermal effect with epidermal cooling, making it safe for all skin types. Understanding the technology behind devices is crucial for selecting the right treatment for a patient's concerns and downtime tolerance.