(A) Applying antibiotic ointment
(B) Taping the skin
(C) Using croton oil
(D) Using liquid soap
The correct response is Option D.

The depth of a phenol peel is decreased by using liquid soap, which increases the surface tension and thus decreases the penetration and absorption of the phenol.

Applying antibiotic ointment and taping the skin increase the depth of a phenol peel by providing a vapor barrier.
Phenol peels are typically based on croton oil, a skin irritant that increases the speed and depth of epidermal destruction. Phenol peels were previously performed according to the Baker formula, which involved placement of the phenol in a solution of distilled water, croton oil, and liquid soap. This formula is no longer used because the solution did not effectively dilute the toxicity of the phenol.

References
1. Greenbaum SS. Chemical peeling, injectable collagen implants and dermabrasion. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith’s Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:597.
2. Rees TD. Chemabrasion and dermabrasion. In: Rees TD, LaTrenta GS, eds. Aesthetic Plastic Surgery. 2nd ed. Philadelphia, Pa: WB Saunders Co; 1994:757.

In patients undergoing dermabrasion, which of the following is the most likely finding at the level of the superficial reticular dermis, indicating the endpoint of treatment?

(A) Coarse, nonbleeding tissue
(B) Confluent bleeding with a coarse tissue background
(C) Smooth, nonbleeding tissue
(D) Sparse, punctate bleeding with a pink tissue background

The correct response is Option B.

Dermabrasion, which is a method of skin resurfacing involving controlled mechanical abrasion of the epidermis and a variable portion of the dermis, is especially useful for treatment of scars, facial rhytides, and the skin deformities associated with rhinophyma. This process results in mechanical depression of scars and elevated tissues and induction of collagen synthesis. Following dermabrasion, wound repair begins in the remnant dermal appendages.

The depth of dermabrasion is determined by clinical endpoints encountered during the treatment process. The epithelium is removed initially; the dermal-epidermal surface is smooth and does not bleed. Sparse, punctate bleeding indicates that the surgeon has reached the superficial papillary dermis. This sparse bleeding becomes greater as the surgeon planes deeper into the papillary dermis, and the background is notably coarser. The level of the superficial reticular dermis is characterized by brisk, confluent bleeding on a coarse tissue background. This indicates the endpoint of treatment because further dermabrasion can lead to permanent scarring.

Although re-epithelialization typically occurs within seven to 10 days following dermabrasion, erythema may persist for as long as six weeks after treatment.

References
1. Baker TM. Dermabrasion: as a complement to aesthetic surgery. Clin Plast Surg. 1998;25:81.
2. Baker TJ, Stuzin JM, Baker TM, eds. Facial Skin Resurfacing. Saint Louis, Mo: Quality Medical Publishing, Inc, 1998.

Which of the following best describes the mechanism of action of botulinum toxin (Botox)?

(A) Inhibition of acetylcholine release at the neuromuscular junction
(B) Inhibition of messenger RNA-mediated production of acetylcholine
(C) Potentiation of the acetylcholine effect at the neuromuscular junction
(D) Prevention of acetylcholine binding at the neuromuscular junction

The correct response is Option A.

Botulinum toxin, also known as Botox, is an exotoxin derived from Clostridium botulinum bacteria. Its neuromuscular mechanism of action involves inhibition of the release of acetylcholine. Botulinum toxin is packaged (typically in units of 100) in a sterile, vacuum-dried form, which must be stored at -5%C (23%F). It can also be reconstituted by diluting it with nonpreserved saline at a rate of 2.5 U/.1 mL.

Botulinum toxin is currently approved by the Food and Drug Administration (FDA) for treatment of glabellar rhytides. However, it is increasingly being used as an “off label” treatment for dispersion of rhytides of the forehead and the periorbital, perioral, and platysmal regions.

References
1. Fagien S. Botox for the treatment of dynamic and hyperkinetic facial lines and furrows: adjunctive use in facial aesthetic surgery. Plast Reconstr Surg. 1999;103:701-713.
2. Fagien S, Brant FS. Primary and adjunctive use of botulinum toxin type A (Botox) in facial aesthetic surgery: beyond the glabella. Clin Plast Surg. 2001;28:127-148.

Which of the following is the most likely result of treatment of the skin with topical tretinoin (retinoic acid)?

(A) Cellular atypia
(B) Consolidation of melanin granules
(C) Decreased collagen synthesis
(D) Thinning of the epidermis
(E) Thinning of the stratum corneum

The correct response is Option E.

Tretinoin, or retinoic acid, is used for antiaging therapy because it can accelerate the reversal of skin damage caused by sun exposure. Its mechanism of action is believed to involve stimulation or oppression of specific genes within nuclear receptors. Tretinoin has been shown to inhibit the binding of AP1 transcription factor to DNA by 70%, thereby decreasing the activation of collagenase, gelatinase, and stromelysin.

Histologic effects associated with tretinoin use include thinning of the stratum corneum, reversal of cellular atypia, and thickening of the epidermis. In the dermis, collagen synthesis is increased and melanin granules are dispersed more evenly.

References
1. Bhawan J, Olsen E, Lufrano L, et al. Histologic evaluation of the long term effects of tretinoin on photodamaged skin. J Dermatol Sci. 1996;11:177.
2. Clark CP III. Office-based skin care and superficial peels: the scientific rationale. Plast Reconstr Surg. 1999;104:854.
3. Klingman AM, Grove GL, Hirose R, et al. Topical tretinoin for photoaged skin. J Am Acad Dermatol. 1986;15:836.
4. Weiss JS, Ellis CN, Headington JT, et al. Topical tretinoin improves photoaged skin: a double-blind vehicle-controlled study. JAMA. 1988;259:527.

A patient is scheduled to undergo injection of bovine collagen (Zyderm) in the glabellar region. A test dose should be administered how many weeks prior to injection?

(A) 1
(B) 2
(C) 4
(D) 8
(E) 12

The correct response is Option C.

Zyderm and Zyplast are highly purified forms of bovine collagen typically injected to provide improvement of rhytides and depressed scars. Because approximately 3% of all treated patients will have an allergic reaction to injectable bovine collagen, skin testing must be performed prior to any treatment. Following intradermal injection of a single test dose, the patient should be assessed 48 hours after injection and again at four weeks after injection. Any adverse changes noted at the test site indicate an allergic reaction, and occasionally reactions appear as long as four weeks after injection. Recently, some physicians have begun to advocate two episodes of antigen exposure, potentially increasing the number of positive reactions and identifying additional patients who may subsequently develop allergic reactions.

References
1. Greenbaum SS. Chemical peeling, injectable collagen, implants, and dermabrasion. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith’s Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:597-608.
2. Klein AW. Skin filling: collagen and other injectables of the skin. Dermatol Clin. 2001;19:491-508.

A 37-year-old woman has symptomatic blepharoptosis on the right one week after undergoing injection of 25 units of botulinum toxin (Botox) into the glabellar region for treatment of dynamic rhytides. Which of the following is the most appropriate management?

(A) Observation
(B) Use of a patch on the left eye for 48 hours
(C) Use of alpha-adrenergic agonist eyedrops
(D) Administration of a beta-adrenergic blocker
(E) Operative correction of ptosis

The correct response is Option C.

In this 37-year-old woman who has symptomatic blepharoptosis following botulinum toxin injection, the most appropriate management is administration of alpha-adrenergic agonist eyedrops. Botulinum toxin (Botox) is associated with numerous other complications, including diplopia, retrobulbar hemorrhage, perforation of the globe, lagophthalmos, photophobia, epiphora, ectropion, and exposure keratitis. Ecchymoses, eyelid retraction, eyebrow ptosis, and asymmetry have also occurred in some patients.

Blepharoptosis results from migration of the toxin from the area of treatment (the glabellar region in this patient) into the levator muscle. This effect is typically transient, as the dose of migrated toxin diminishes significantly. Patients with mild to moderate symptoms should be reassured that condition is typically self-limiting, and no treatment is recommended. If the blepharoptosis is moderate to severe, ocular decongestants, such as the alpha-adrenergic agonists antazoline and naphazoline, are administered. These eyedrops act to contract Müeller’s muscle temporarily and thus elevate the upper eyelid margin, relieving the symptoms.

References
1. Fagien S. Botox for the treatment of dynamic and hyperkinetic facial lines and furrows: adjunctive use in facial aesthetic surgery. Plast Reconstr Surg. 1999;103:701-713.
2. Fagien S, Brant FS. Primary and adjunctive use of botulinum toxin type A (Botox) in facial aesthetic surgery: beyond the glabella. Clin Plast Surg. 2001;28:127-148.

Which of the following substances is NOT contained in Jessner’s solution?

(A) Ethanol
(B) Glycolic acid
(C) Lactic acid
(D) Resorcinol
(E) Salicylic acid

The correct response is Option B.

Jessner’s solution is incorporated into skin peeling agents to even the depth of the peel and improve exfoliation. This solution, which contains ethanol, lactic acid, resorcinol, and salicylic acid, is often used for treatment of hyperpigmentation. The mechanism of action of Jessner’s solution is believed to be destruction of intracellular connections between keratinocytes as well as removal of the epidermis. Its use results in increased epidermal turnover and a decreased quantity of melanin-counting keratinocytes.

Because the depth of penetration of Jessner’s solution is limited, the rate of complications is decreased. Mild erythema develops following the first application, which may worsen over time. Additionally, frosting of the skin may be seen with further application.

References
1. Brody HJ. Update on chemical peels. Adv Dermatol. 1992;7:275.
2. Clark CP III. Office-based skin care and superficial peels: the scientific rationale. Plast Reconstr Surg. 1999;104:854.
3. Dolezal J. Jessner’s solution. In: Rubin MG, ed. Manual of Chemical Peels, Superficial and Medium Depth. Philadelphia, Pa: JB Lippincott Co; 1992.