Laser Vascular Treatment Reduces Red Scars and Dilated Blood Vessels: How PDL Works and How Many Sessions Are Needed?

In recent years, the term "vascular laser treatment" has become increasingly common in cosmetic dermatology clinics and on social media, associated with advertisements that may obscure red scars and other post-acne or surgical marks, as well as treating dilated blood vessels on the face. This demand is significant: many people continue to experience persistent red marks months after acne, or visible broken capillaries on their cheeks and nose, affecting their confidence. Among vascular laser treatments, pulsed dye laser (PDL) — also known as selective photothermolysis — is a technology with extensive research history and frequent mention. However, amidst the hype, patients need to understand what PDL can achieve, its limitations, how many sessions are required, and why results depend heavily on individual anatomy.

What Are Red Scars and Dilated Blood Vessels?

These two conditions are often confused but have distinct underlying causes, despite both being related to superficial blood vessels in the skin:

• Red Scar (erythematous scar): is a persistent red mark left during the healing phase of a scar, commonly occurring after acne inflammation, surgery, or trauma. The redness comes from increased small blood vessel formation within the non-healed scar tissue. Many cases gradually fade over time, but some can persist for months.
• Dilated Blood Vessels (telangiectasia): are small, dilated blood vessels that appear as red lines or spots on the skin, often found on the cheeks and nose, possibly related to rosacea, sun exposure, or individual anatomy.

Both conditions share a common component of "vessels" as the primary target, making them potentially treatable with laser treatments targeting blood vessels — this is the basis for PDL.

What Is PDL and How Does It Work?

Pulsed dye laser uses yellow wavelengths (typically around 585–595 nm), which are absorbed by hemoglobin in red blood cells. The underlying principle is selective photothermolysis: the laser energy is absorbed more strongly by the blood vessels than surrounding tissue, heating and damaging the target vessel while minimizing damage to healthy skin.

When small blood vessels within a red scar or dilated blood vessels on the face are exposed to the laser, they may contract, clot, or be gradually cleared by the body, leading to fading of the red mark. For scars, some studies have noted that PDL can also affect collagen re-organization, contributing to improvements in both color and thickness of non-healed scar tissue. However, this is a gradual biological process, not an immediate effect after a single treatment.

For Which Conditions Is PDL Indicated?

In dermatology, laser treatments targeting blood vessels, including PDL, are typically considered for:

• Red scars from acne, surgery, or trauma that are still red and have not yet transitioned to white, mature scars.
• Dilated blood vessels on the face, such as broken capillaries on the cheeks and nose.
• Other vascular injuries like port-wine stains (telangiectasia) — depending on a dermatologist's assessment.
• Supporting flatter and softer non-healed scars in some combined treatment protocols.

Note: PDL is not suitable for all types of scars. Eruptive scars (pitted scars) are mainly structural issues, typically requiring surface laser resurfacing, dermabrasion, or other methods; mature, white scars usually do not contain blood vessels that PDL can target. Accurately identifying the type and stage of scar is crucial in determining whether to use vascular laser treatments.

How Many Sessions Are Needed and What Can We Expect?

This is the most frequently asked question but also where exaggerated advertising claims often arise. In reality, most cases require multiple sessions, typically spaced a few weeks apart for skin recovery between treatments. Red scars and dilated blood vessels rarely disappear after a single session. Some key points to understand:

• Number of sessions varies by individual: depending on the redness, depth, density of blood vessels, location, skin type, and personal response. There is no fixed number that applies to everyone.
• Improvement tends to be gradual: red marks fade over multiple sessions rather than "white out" immediately.
• Uneven responses are common: some people see significant improvement while others experience limited results; a certain percentage of blood vessels may reappear over time, especially with facial telangiectasia due to individual anatomy or continued sun exposure.

Therefore, any promises like "no red marks after one session" or "permanent removal of blood vessels" should be taken with caution. Current evidence supports PDL as a useful option for vascular injuries, but the degree and longevity of results depend on specific indications and individual responses.

Cautionary Note About Overhyped Advertising

The terms "vascular laser treatment" or "PDL" on product labels do not automatically guarantee effectiveness or safety. Patients should be wary when encountering these signs:

• Guaranteed 100% results without scientific basis.
• No mention of the number of sessions required, risks, contraindications, or recurrence potential.
• Generalizing all types of scars (including pitted and white scars) into a single vascular laser treatment protocol.
• Not requiring pre-treatment consultations, skin assessments, scar type identification, and stage evaluation.

True effectiveness depends on selecting the right device, wavelength, parameters, and physician skill in setting appropriate energy levels for each individual area of skin, as well as post-treatment care — not just the popularity of the technology's name.

Important Considerations for Skin Type and Safety

This is a crucial point often overlooked by patients. Most Vietnamese skin tends to darken after inflammation, making any laser treatment potentially risky if the parameters are not tailored to individual anatomy. After PDL, temporary side effects may include redness, mild swelling, and a distinctive purple discoloration (purpura) at the treated area, which can last from a few days to over a week depending on the parameters — this needs to be disclosed in advance. Other risks include changes in skin tone (temporary darkening or lightening), sunburn, or scarring if not performed correctly. Some situations require special consideration or delay: infected treatment areas, excessive sun exposure, use of photosensitivity medications, history of easy scarring, or uncontrolled dermatological conditions. Effectiveness and safety vary significantly between individuals, so treatments should only be conducted after a direct consultation with a specialist dermatologist at a reputable medical facility equipped with FDA-approved devices. Post-laser care, especially strict sun protection, significantly impacts results and recurrence prevention.

Dr. Vo Thanh Sang's Perspective

According to Dr. Vo Thanh Sang, vascular laser treatments like PDL are suitable for groups of injuries with blood vessel components such as non-healed red scars and facial telangiectasia, but should not be considered a "color fix" for all types of scars. The doctor emphasizes individualized treatment: first identifying the correct type and stage of scar, as pitted or mature white scars require different approaches. Realistic goals are typically gradual fading and improvement over multiple sessions, combining sun protection and skin care rather than expecting complete disappearance after one session. While the same device may be used, parameters will vary by individual, based on thorough consultations rather than following trends.

If you are considering vascular laser treatment for red scars or facial telangiectasia, prioritize getting direct advice and a skin assessment from a specialist dermatologist to understand your skin condition, benefits, limitations, expected number of sessions, and risks specific to your anatomy. For further information, you can contact the hotline 079 7479 222. This article is informational and does not replace personal medical consultations or individualized treatment plans.