Treatment of other skin lesions with lasers

Different lasers have been used for the treatment of various skin lesions. The carbon dioxide (CO2) laser is the most common application. The Neodymium:Yttrium-Aluminum-Garnet Laser, Argon Laser, the Pulsed-Dye Pigmented Laser and Q-Switched Ruby Laser have also been used effectively for the treatment of skin lesions.

The CO2 laser has a wavelength of 10,600 nm, a superficial penetration depth that makes it useful for treatment of benign lesions and ensures lesser surrounding healthy tissue damage. The argon laser with wavelengths in the range of 488 and 514.5 nm has a limited penetration capacity. The Nd:YAG has a wavelength of 1064 nm with preferential absorption. The Pulsed-DyePigmented Laser has a wavelength of 510 nm and the Q-Switched Ruby Laser gives 694 nm. The Pulsed Dye Laser at 585 nm with high energy and short pulse duration is highly specific and causes minimum damage to surrounding tissues and hence less scarring.

The various skin lesions that can be treated with the lasers mentioned above:

Refractory warts

PDL is now the preferred choice over CO2 laser in the treatment of refractory warts, though initially it was the latter that was used especially for plantar and periungual warts and condyloma. Plantar and periungual verrucae are types that are unmanageable by other treatment modes like electrodesiccation and curettage, cryotherapy, and salicylic acid therapy. In these cases, CO2 lasers have shown varying results which are greatly dependent on professional expertise.

Other comparative studies have reported the following rates of cure and scarring respectively, but all with more accurate control over thermal damage:

• Continuous-wave CO2 - 68% and 54%
• The superpulsed CO2 - 68% and 33%
• The ultrapulsed CO2 - 90% and 7%

However, limited penetration is a disadvantage of ultrapulsed laser, which also increases the treatment duration and number of pulses. Moreover, there are risks of infection for the operators in case of the CO2 treatment of verrucae and stringent precautions are necessary.

Rhinophyma

Rhinophyma are skin lesions on the nose. CO2 laser treatment has the advantages of high precision, effective hemostasis and least heat conduction for this disease. However, the newer, short-duration, higher peak power CO2 lasers are preferred over the older continuous-wave CO2 types to reduce scarring due to heat conduction. However, CO2 lasers are not too suitable for thick rhinophymas due to the short ablations involved.

Epidermal nevi

CO2 lasers have made treatment of epidermal nevi a lot easier and reduced recurrence that occurs with dermabrasion and scarring caused by more forceful applications like excision. The ultrapulsed CO2 laser is preferred over the continuous wave CO2 laser. The higher-peak power, shorter-duration CO2 lasers is more accurate but could cause scarring.

Seborrheic keratoses

Thick and large seborrheic keratoses have been removed with a single treatment in some experiments with the continuous-wave CO2 or superpulsed CO2 lasers, but with some atrophic scarring. The ultrapulsed CO2 laser however showed no scarring and less thermal damage. However, most of the results are operator dependent.

The Nd:YAG is also effective on early seborrheic keratoses and the pulsed-dye pigmented lasers are efficient on flat seborrheic keratoses. The argon laser is also a treatment option, but since it is a continuous type it can cause scarring. The Q-Switched Ruby Laser reports a 75% success with seborrheic keratoses.

Angiofibromatous and angiolymphoid lesions

CO2 lasers with minimum heat damage, high-peak power, shorter-exposure is best suited for highly fibrous lesions like adenoma sebaceum, angiokeratoma, pyogenic granuloma, and lymphangioma circumscriptum. It also causes less scarring and is more effective than the argon laser.

Ulcers

CO2 and Neodymium: yttrium-aluminum-garnet (Nd:YAG) laser have shown good results on chronic ulcers. If well debrided and sterilized by these two processes it can ensure a speedy healing.

Verrucae

Verrucae are a virally infected tissue, with 10 % prevalence. PDL at 585 nm has been successfully implemented in a study upon recalcitrant verrucae. The process has been ensured with selective destruction of the infected tissues thus reducing surrounding tissue damage and associated scarring.

Angiofibromas

Pulsed Dye Laser at 585 nm in 2 to 3 treatment sessions is effective in clearing nonfibrous angiofibromas. It has the advantage of lesser scarring. Argon laser also works well on angiofibromas, but has a limited penetration till the upper 1 mm of the dermis and risk of scarring.

Acne rosacea

PDL is suitable for the treatment of the vascular constituents of the inflammatory acne rosacea, which is accompanied with telangiectasia and erythema. It has a success rate of 59%. Argon lasers work well on telangiectasia.

Superficial dermal lesions

The various benign superficial dermal tumors that have been successfully cleared by the continuous-wave and superpulsed CO2 lasers are:

• Neurofibroma
• Milia
• Myxoid cyst
• Sebaceous hyperplasia
• Apocrine hidrocystoma
• Adenoma sebaceum
• Chondrodermatitis nodularis chronica helices
• Collagenoma
• Elastoma
• Granuloma
• Faciale
• Syringoma
• Trichoepithelioma
• Tricholemmoma
• Xanthelasma

Other inflammatory conditions that can be treated with CO2 laser include:

• Darier’s disease
• Hidradenitis
• Lichen sclerosus
• Zoon’s balanitis
• Hailey-Hailey disease
• Lichen planus