PulsedDye

Pulseddye refers to pulsed dye laser (PDL) technology, a medical laser system used to treat vascular conditions of the skin. A typical PDL emits short pulses of yellow light in the 585–595 nanometer range. The light is absorbed by oxyhemoglobin in blood vessels, causing selective photothermolysis that coagulates the targeted vessels with minimal damage to surrounding tissue.

Mechanism and parameters. The short pulse duration is designed to be comparable to the thermal relaxation time of superficial and mid-dermal vessels, enabling selective targeting. Pulse durations commonly range from about 0.45 to several milliseconds, with repetition rates typically between 1 and 10 Hz. Fluence (energy per area) and spot size are adjusted based on vessel size, depth, and treatment area. Cooling strategies are often used to improve comfort and protect the epidermis.

Clinical applications. PDL is widely used to treat vascular skin lesions, including port-wine stains (capillary malformations), facial and truncal telangiectasias, and acquired vascular lesions such as rosacea-related redness. It is also employed to improve erythema in hypertrophic scars and certain keloids, to treat some haemangiomas in adults, and to reduce redness in various dermatologic conditions.

Advantages and limitations. PDL offers relatively high efficacy for superficial to mid-dermal vessels with a favorable safety profile when performed by trained professionals. Common short-term effects include redness, swelling, and purpura (bruise) that may last days to weeks. Risks include transient pigmentary changes, particularly in darker skin types, as well as rare scarring or blistering if misused. Deeper vascular lesions may respond less well, and multiple sessions are often required.

History and usage. Since its development in the late 20th century, PDL has become a standard modality in dermatology for vascular indications, with numerous devices and clinical protocols in widespread use.