Can Long-Pulse Alexandrite Lasers Revolutionize Cosmetic Dermatology?

🔍 Key Finding Long-pulse alexandrite lasers effectively treat hair removal, vascular lesions, and pigmented lesions, showing particular promise for thicker infantile hemangiomas and hypertrophic port-wine stains. Treatment parameters like fluence, spot size, and pulse width, along with the use of dynamic cooling devices, should be tailored to individual patient characteristics and lesion types for optimal efficacy and minimal side effects.

🔬 Methodology Overview

• Design: Narrative review.
• Data Sources: Published research articles on long-pulse alexandrite lasers in cosmetic dermatology.
• Selection Criteria: Studies focusing on the use of long-pulse alexandrite lasers for hair removal, vascular lesions (infantile hemangiomas, angiokeratoma circumscriptum, telangiectasia, port-wine stains), and pigmented lesions (lentigo, freckles, melasma, seborrheic keratosis, Becker’s nevus).
• Analysis Approach: Qualitative synthesis and summarization of findings from selected studies.
• Scope: Clinical applications of long-pulse alexandrite lasers in cosmetic dermatology, including discussion of treatment parameters, efficacy, and side effects.

📊 Results

• Hair Removal: Long-pulse alexandrite lasers achieved an average hair removal rate of 81% in individuals with light skin tones and 88% in those with dark skin tones. Another study reported a >91% hair reduction across various body areas in patients with Fitzpatrick skin types II-VI.
• Pseudofolliculitis Barbae (PFB): Long-pulse alexandrite laser reduced papules and hair density by nearly 80% after 7 treatments, showing superior results compared to Intense Pulsed Light (IPL).
• Acne Keloidalis Nuchae (AKN): Early intervention with long-pulse alexandrite laser showed a 90% reduction in papules, 98% reduction in pustules, and 54.5% reduction in keloidal plaque size after six treatments, with no recurrences during follow-up.
• Infantile Hemangiomas (IH): Long-pulse alexandrite laser showed efficacy in treating thick/deep IH, with complete regression observed in some cases. Combination with other treatments like timolol maleate or 595nm pulsed dye laser also showed promising results.
• Angiokeratoma Circumscriptum (AC): Long-pulse alexandrite laser, alone or in combination with PDL, showed significant reduction in AC lesions (90% reduction in one case after 3 treatments).
• Telangiectasia: Effectiveness varied depending on vessel size. A 65% reduction in leg vessels was observed with optimal parameters (60 ms, 89 J/cm², 6 mm spot size), but the laser was less effective on vessels smaller than 0.6 mm.
• Port Wine Stains (PWS): Long-pulse alexandrite laser demonstrated superiority over PDL in treating hypertrophic PWS. It also showed the best results for hypertrophied and PDL-resistant vessels in skin with low to moderate melanin concentrations.
• Pigmented Lesions: Long-pulse alexandrite laser effectively cleared lentigines (76-99% clearance) and showed improvement in melasma (30.5% mMASI score reduction). It also showed promise in treating seborrheic keratosis and Becker’s Nevus (>50% clearance in a majority of patients).

💡 Clinical Impact Long-pulse alexandrite lasers show promise in treating various dermatological conditions, including hair removal, vascular lesions, and pigmented lesions, offering potentially effective and safe outcomes. This necessitates further systematic studies with larger sample sizes and comparisons with other lasers to solidify its place in treating specific conditions like venous lakes of lips, recalcitrant viral warts, and basal cell nevus syndrome, potentially expanding treatment options for these conditions.

🤔 Limitations

• Limited long-term efficacy data for long-pulse alexandrite lasers.
• Lack of systematic studies with larger sample sizes for some applications.
• Lack of head-to-head comparisons with other laser types for some conditions.
• Potential for epidermal damage before vessel damage in small telangiectasias.
• Risk of hyperpigmentation in patients with darker skin types, especially at higher fluences.
• Less effective on dermal melasma compared to epidermal melasma.
• Potential for under- or overexposure of treatment areas when using dynamic cooling devices.

✨ What It Means For You This review summarizes the effectiveness and safety of long-pulse alexandrite lasers for various dermatological conditions, including hair removal, vascular lesions, and pigmented lesions, offering guidance on treatment parameters based on skin type and lesion characteristics. Doctors should consider this laser for treating these conditions, particularly for thicker infantile hemangiomas, angiokeratoma circumscriptum, and hypertrophic port-wine stains, while being mindful of potential side effects like hyperpigmentation in darker skin types. Further research is encouraged to explore combination therapies and expand the applications of this laser.

Reference Chen C, Ke Y. Applications of Long-Pulse Alexandrite Laser in Cosmetic Dermatology: A Review. Clinical, Cosmetic and Investigational Dermatology. 2023;16:3349-3357. https://doi.org/10.2147/CCID.S441169