A 23-year-old woman has carbonaceous material embedded in the skin after sustaining injuries in a combustion accident at work. A photograph is shown above. Which of the following is the most appropriate management?

(A) Carbon dioxide laser therapy
(B) Nd:YAG laser therapy
(C) Deep dermabrasion
(D) Wide local excision and coverage with a thin split-thickness skin graft

The correct response is Option B.

In patients who have certain types of foreign material embedded in the skin, especially road asphalt, carbonaceous material, or ink from amateur tattoos, the most appropriate method of removal is multiple treatments with the Nd:YAG laser.

In the past, traumatic tattoos were removed with mechanical abrasive techniques, including dermabrasion, salabrasion, and the rubbing of table salt into the skin, each of which produced satisfactory results in superficial tattoos. However, better results have recently been demonstrated with laser therapy, which involves the removal of successive layers of skin to expose the intradermal pigment, which is subsequently vaporized.

The surgeon should take great care while administering Nd:YAG laser treatments in any patient who has sustained injuries resulting from a gunpowder or fireworks accident, as the unburned, embedded gunpowder can actually combust during treatment, leading to unacceptable scarring.

Although laser therapy is the treatment of choice for traumatic tattoos, the carbon dioxide laser is not recommended because it does not effectively remove embedded carbonaceous material. In addition, this laser has no selective absorption; as a result, epidermal structures are injured more easily and scarring is increased.

Deep dermabrasion and wide local excision combined with thin split-thickness skin grafting are excessively invasive procedures that will yield poor cometic results.
References
1. Haywood RM, Monk BE, Mahaffey PJ. Treatment of traumatic tattoos with the Nd:YAG laser: a series of nine cases. Br J Plast Surg. 1999;52:97-98.
2. Raulin C, Schonermark MP, Greve B, et al. Q-switched ruby laser treatment of tattoos and benign pigmented skin lesions: a critical review. Ann Plast Surg. 1998;41:555-565.
3. Suzuki H. Treatment of traumatic tattoos with the Q-switched neodymium:YAG laser. Arch Dermatol. 1996;132:1226-1229.
4. Taylor CR. Laser ignition of traumatically embedded firework debris. Lasers Surg Med. 1998;22:157-158.
5. Troilius AM. Effective treatment of traumatic tattoos with a Q-switched Nd:YAG laser. Lasers Surg Med. 1998;22:103-108.

Which of the following findings is more likely in patients who undergo resurfacing with the erbium:YAG laser than in patients treated with the carbon dioxide laser?

(A) Erythema
(B) Hypopigmentation
(C) Scarring
(D) Skin tightening
(E) Transudate wound

The correct response is Option E.

The erbium:YAG (Er:YAG) laser is now the treatment of choice for ablative resurfacing of the skin. This laser emits light at a wavelength of 2940 nanometers (nm) and is absorbed by water within the epidermis a minimum of 10 times more efficiently than the carbon dioxide laser. The decreased dermal heating that occurs during treatment with the Er:YAG laser results in minimal long-term contraction of the dermis, but produces a transudative wound once the epidermis has been eliminated. The transudation becomes more profuse as the surgeon ablates deeper into the dermis.

Because the mechanism of action of the Er:YAG laser is photomechanical rather than photothermal, coagulation necrosis is limited and hyperemia is decreased. As a result, permanent hypopigmentation occurs in less than 5% of patients undergoing treatment with the Er:YAG laser. In contrast, permanent hypopigmentation has been reported in as many as 40% of patients undergoing carbon dioxide laser therapy.

Scarring may occur with any type of laser and is related to the amount of heat generated from the laser, also known as its pulse.

Likewise, skin tightening occurs with both the Er:YAG and the carbon dioxide laser.

References
1. Alster TS, Lupton JR. Erbium:YAG cutaneous laser resurfacing. Dermatol Clin. 2001;19:453.
2. Gregory RO. Overview of lasers in plastic surgery. Clin Plast Surg. 2000;27:167.
3. Weinstein C. Erbium laser resurfacing: current concepts. Plast Reconstr Surg. 1999;103:602.

Which of the following laser wavelengths has the greatest affinity for water?

(A) 585 nm
(B) 1064 nm
(C) 1320 nm
(D) 2940 nm
(E) 10,600 nm

The correct response is Option D.

The erbium:YAG (Er:YAG) laser emits light at a wavelength of 2940 nanometers (nm) and is absorbed by water within the epidermis a minimum of 10 times more efficiently than the carbon dioxide laser. Its mechanism of action involves photomechanical injury to the targeted tissue.

The 585-nm pulsed-dye laser is used in the treatment of cutaneous vascular lesions.

The lesser-energy, variable pulsed-width frequency, double Q-switched Nd:YAG laser and the higher-energy, millisecond pulsed Nd:YAG laser both have a wavelength of 1064 nm. The double Q-switched Nd:YAG laser is appropriate for the removal of hair or tattoos, and the millisecond pulsed Nd:YAG laser is indicated for treatment of vascular lesions.

The 1320-nm wavelength is incorporated by many nonablative lasers that stimulate collagen production within the dermis. Although the target of these 1320-nm lasers is water, they have 50% less affinity for water than the Er:YAG laser.

The carbon dioxide laser emits light at a wavelength of 10,600 nm. In contrast to the photomechanical action of the Er:YAG laser, the carbon dioxide laser produces photothermal injury. In addition, it has less specificity for its target, resulting in greater collateral injury, including greater contraction of the skin and dermis and increased collagen remodeling. As a result, recovery time is prolonged, and the risk for hyperpigmentation and other associated complications is greater.

References
1. Alster TS, Lupton JR. Erbium:YAG cutaneous laser resurfacing. Dermatol Clin. 2001;19:453.
2. Gregory RO. Overview of lasers in plastic surgery. Clin Plast Surg. 2000;27:167.
3. Weinstein C. Erbium laser resurfacing: current concepts. Plast Reconstr Surg. 1999;103:602.