DIR Questions

Question 1

What is the laser of choice for solar lentigines?

Answer 1

Targeting the melanosomes in these benign, superficial pigmented lesions would be most successfully accomplished with the intense pulsed light source.

Question 2

Telangiectasias are most effectively treated by which of the following wavelengths?

• 1550 nm
• 10,600 nm CO₂
• 2940 nm Er:YAG
• 755 nm Alexandrite
• 532 nm long pulsed KTP

Answer 2

The 1550nm, the CO2 10600nm, and the erbium 2940nm lasers target water and do not target the hemoglobin. The alexandrite 755nm laser targets melanin not hemoglobin.

These are telangiectasias which are most effectively treated with the long pulsed 532nm KTP laser.

Question 3

What is the result of a marginal mandibular nerve injury?

Answer 3

Inability to depress and retract the lip on the affected side

The mouth would seem normal at rest, but crooked when attempting to smile.

The marginal mandibular nerve innervates the depressor anguli oris, depressor labii inferioris, mentalis, orbicularis oris, risorius, and platysma muscles. Depression and retraction of the lip is controlled by depressor anguli oris, depressor labii inferioris, and mentalis muscles.

Question 4

The most important function of a postoperative wound dressing is:

Answer 4

Providing hemostasis to a wound is the most important function of a wound dressing

Question 5

What is the soft triangle of the nose?

Answer 5

Question 6

FTSGs are more likely than STSGs to demonstrate which of the following:

• Alopecia
• Contraction
• Necrosis
• Hypohidrosis
• Hypopigmentation

Answer 6

Full thickness skin grafts have more adnexal structures, vessels, and structures to supply. Therefore, their metabolic demands are higher and they are more prone to necrosis. However, they are less prone to contraction, alopecia, hypohidrosis, and hypopigmentation for similar structural reasons.

STSG lack adnexal structures, they demonstrate extremely poor cosmesis due to alopecia, hypopigmentation, and hypohidrosis. They are are also prone to contraction.

Question 7

Within which anatomic plane does the inferior/superior labial artery encountered in a lip wedge repair lie?

Answer 7

The inferior labial artery is derived from the facial artery or superior labial artery, and runs through the submucosal tissue horizontally.

Question 8

The auriculotemporal nerve is a branch of what cranial nerve?

Answer 8

CN V3 (mandibular nerve)

Question 9

What chemotherapy may have protective effects against skin cancer?

Answer 9

Rapamycin (also called sirolimus) is a macrolide antibiotic and a structural analog of FK 506. It is a potent immunosuppressive agent which inhibits mTOR (a member of P13K family kinases). Despite its immunosuppressive effects, preliminary data show a decreased incidence of skin cancer in organ transplant patients treated with rapamycin and postulate that it may exert a protective effect against cutaneous malignancies.

Question 10

The maximum adult dosage of lidocaine is _____ without epinephrine and _____ with epinephrine.

Answer 10

The maximum adult dosage of lidocaine is 4.5 mg/kg without epinephrine and 7 mg/kg with epinephrine.

Question 11

What divides the cosmetic units of the lower lip and chin?

Answer 11

Mental crease

Question 12

Which of the following has the least tissue reactivity?

• Silk
• Ethilon
• Dermalon
• Prolene
• Dacron

Answer 12

Prolene

Ethilon, Dermalon and Dacron have low reactivity as well, but Prolene has the least reactivity

Question 13

On average, how much does a full-thickness graft contract when removed from a donor site?

Answer 13

On the average, a full-thickness graft may contract by about 15% when removed from a donor site.

Question 14

A Z-plasty represents which type of flap?

Answer 14

A Z-plasty is a type of transposition flap that is useful for scars crossing relaxed tensions lines or releasing contractures (redistributes tension over wound).

A Z-plasty involves the movement of tissue via transpositioning across intervening islands of unaffected tissue.

Question 15

What is the most effective topical treatment option for pulsed dye laser-induced purpura? Hint: it is a vitamin.

Answer 15

Vitamin K oxide gel appears to hasten the resolution of pulsed dye laser-induced purpura in subjects being treated for bilateral facial telangiectasia, and may well be useful in accelerating resolution of facial bruising from other cosmetic procedures such as fillers used for soft-tissue augmentation as well as other types of cutaneous surgical procedures.

Question 16

What is the best choice of a wavelength of a laser to treat the changes you see here?

• 595 nm
• 1,064 nm
• 810 nm
• 755 nm
• 10,600 nm

Answer 16

CO2 resurfacing and ablative lasers (10,600 nm) are the best for severe rhinophyma as is seen here.

Question 17

What is the most commonly associated tattoo pigment with allergic reactions - both eczematous and granulomatous?

Which tattoo pigment is most commonly associated with phototoxic reactions?

Answer 17

Mercuric sulfide, which appears red in color.

Of note, Cadmium sulfide is the tattoo pigment most commonly associated with phototoxic reactions. It appears yellow.

Question 18

Which sclerosant is most painful and has the highest risk of cutaneous necrosis?

Answer 18

Hypertonic saline has the highest risk of cutaneous necrosis. The disadvantage of hypertonic saline is pain associated with injections and ulcerogenic potential.

Question 19

A Z- plasty is performed to:

Answer 19

A Z-plasty is a type of transposition flap that may be used to lengthen a scar, reorient a scar, or break down scars into smaller subunits with a more camoflouged appearance. This can be especially helpful when the scar crosses skin tension lines or when there is distortion of free margins by a scar.

Question 20

Glogau’s photoaging classification

Answer 20

Question 21

What laser is the best choice for a cherry angioma?

• 1,450 nm
• 755 nm
• 694 nm
• 585 nm
• 510 nm

Answer 21

585 nm (PDL)
The remaining answer choices do not target hemoglobin as a chromophore, so they would not be the best option in treating this cherry angioma:
1450nm-Diode laser (target chromophore: water)
755nm-Alexandrite laser (target chromophore: melanin)
694nm-Ruby laser (target chromophore: melanin)
510nm-short wavelength Pulsed dye laser (target chromophore: melanin)

Question 22

Healing by secondary intention will offer the most favorable cosmetic result at which location?

• Nasal tip
• Malar cheek
• Chin
• Forehead
• Medial canthus

Answer 22

Anatomic sites lending themselves best to second intention healing, with excellent results, are the concave areas on the face. These include the medial canthus, the nose-cheek junction, the auricular concha, the preauricular cheek, and the retroauricular scalp. The nasal tip, malar cheek, chin and forehead are all convex surfaces on the face.

Question 23

What laser could be used to treat granuloma faciale?

Answer 23

PDL (585 nm)

Question 24

What type of anesthesia should be used for endovenous radiofrequency ablation or laser ablation?

Answer 24

Tumescent anesthesia is used for endovenous radiofrequency ablation and endovenous laser ablation. This allows separation of the vessel from the surrounding tissue, thereby protecting surrounding tissue (including nerves) from injury.

Question 25

Which formulation of botulinum neurotoxin does not contain complexing proteins?

Answer 25

Incobotulinum toxin A (Xeomin)

Question 26

A patient with a deep vertical frown line in the glabellar region requests Botox. Treatment will mostly target which one of the following muscles?

Answer 26

Although the procerus and orbicularis oculi muscles are contributory, the development of vertical glabellar frown lines is mostly due to the overactivity of the **corrugator supercilaris**. These muscles function to pull the eyebrow inferomedially. Procerus muscle contraction contributes largely to the transverse (horizontal) rhytides along the nasal root. Orbicularis oculi contraction contributes to crow's feet rhytides radiating from lateral canthal region.

Question 27

Which of the following does require neutralization? * Jessner's * TCA * Salicylic acid * Glycolic acid * Baker-Gordon

Answer 27

**Glycolic acid peels** required neutralization with sodium bicarbonate. The others listed do not require neutralization. All alpha hydroxy acids need neutralization, including glycolic acid, lactic acid and mandelic acid. The other answer choices (Jessner's, TCA, salicylic acid, and Baker-Gordon) do NOT require neutralization.

Question 28

Which of the following suture materials induces the least inflammation? * Surgical gut * Polyglycolic acid (Dexon) * Polyglycan 910 (Vicryl) * Polypropylene (Prolene) * Silk

Answer 28

Prolene is a nonabsorbable suture material that evokes only minimal inflammation. Vicryl, Dexon, silk and surgical gut are associated with more inflammation than prolene.

Question 29

Which of the following medications has demonstrated efficacy in the treatment of dermatofibrosarcoma protuberans (DFSP)? * Dabrafenib * Ipilimumab * Gefitinib * Erlotinib * Imatinib

Answer 29

DFSP is most often due to a reciprocal translocation of t(17;22)(q22;q13) resulting in fusion of collagen 1-alpha-1 and _platelet-derived growth factor_ B (COL1A1-PDGFB) which serves as an oncogene. This is the basis of treatment with **imatinib, a PDGF inhibitor.** Dabrafenib, a BRAF inhibitor, and Ipilimumab, a CTLA-4 inhibitor, are used in the treatment of metastatic melanoma.

Question 30

How does electrofulguration protect underlying tissue from heat?

Answer 30

Electrofulguration allows an electric spark to jump to the skin causing **superficial epidermal carbonization**, protecting the underlying tissue from heat.

Question 31

What is the mechanism of action of apraclonidine (Iopidine)?

Answer 31

**Alpha agonist** which results in **contraction of the superior tarsal muscle** Eyelid ptosis is a known potential complication of glabellar treatment with neurotoxins, likely due to diffusion of medication into the orbit and **affecting the levator palpebrae superioris muscle**. Apraclonidine is an alpha-agonist which can improve the ptosis by causing **contraction of the superior tarsal muscle** (occasionally referred to as **Müller's muscle**).

Question 32

Which of the following cosmeceuticals is NOT a pigment lightener? 1. Green tea 2. Arbutin 3. Licorice extract 4. Vitamin C 5. Aleosin

Answer 32

**1. Green tea** is an antioxidant and contains antioxidant polyphenols. It is NOT a pigment lightener. 2 - Arbutin: Arbutin is a naturally occurring gluconopyranoside; decreased tyrosinase activity and may inhibit melanosomal maturation. 3 - Licorice extract: Licorice extract contains liquiritin and isoliquertin, which disperse melanin, and glabridin, which inhibits tyrosinase. 4 - Vitamin C: Vitamin C may interrupt melanogenesis by interacting with copper ions. 5 - Aleosin: Aleosin is a naturally occurring hydroxymethylchromone; inhibits tyrosinase by competitive inhibition.

Question 33

Which anesthetic has the shortest duration of action?

Answer 33

Procaine has the shortest duration of action, only lasting about 30-60 minutes. It is an ester anesthetic and is commonly used in dentistry.

Question 34

Which of the following can work in a wet field? 1. Electrocautery 2. Electrodessication 3. Electrofulguration 4. Electrosection 5. Electrocoagulation

Answer 34

Electrocautery is the only answer listed that is not a type of electrosurgery, thus it can work in a wet field as it has no current and works via heat. The remaining answers are types of electrosurgery, which by definition utilize electric currents and thus do not work in wet fields.

Question 35

What is the term used to describe the parallel nature of coherent light waves?

Answer 35

Collimation is the parallel nature of coherent light waves. Monochromaticity is the emission of a single wavelength. Coherence is the term for light waves traveling in phase. Energy is the fundamental unit of work. Power is the rate of energy delivery measured in watts.

Question 36

What is the desired clinical endpoint when treating tattoos or pigmented lesions with Q-switched lasers?

Answer 36

**Tissue whitening** is the desired clinical endpoint when operating a Q-switched laser.

Question 37

This muscle overlies the nasal bone and attaches to the nasal root and is also responsible for the "bunny lines" of the nose.

Answer 37

The **nasalis muscle** is responsible for the foreshortening of the nose. It is responsible for the "bunny lines" that can be treated with Botox injection.

Question 38

Which of the following lasers has the greatest depth of penetration into the skin? 1. PDL 2. KTP 3. Nd:YAG 4. CO2 5. Erbium

Answer 38

Depth of penetration is proportional to wavelength until ~1200nm, as above that water is absorbed and there is increased scatter with less depth of penetration. The **ND:YAG laser** emits energy at 1064nm near the infrared range and penetrates the skin to the level of the **deep dermal blood vessels**. Although both the erbium and CO2 lasers have longer wavelengths (and thus theoretically allow for deeper penetration), the chromophore for these lasers is water, which is present in such high concentrations in the stratum corneum and superficial epidermis, that the majority of the energy gets absorbed in these superficial layers.

Question 39

What is a notable potential side effect of ambulatory tumescent liposuction?

Answer 39

**Breast enlargement** is a relatively common and unexpected side effect of tumescent liposuction. Since the majority of these patients report increased breast size in the absence of weight gain, some authors postulate shifting hormone ratios as the etiology of this paradoxical breast augmentation.

Question 40

Yellow skin can be camoflauged with what complementary-colored foundation, yielding brown tones? What about red skin, brown skin, and white skin?

Answer 40

**Purple** ## Footnote 1 - Green: Red discoloration can be camouflaged by applying a green foundation, since green is the complementary color to red. Brown: Brown hyperpigmentation from skin conditions such as melasma, lentigines, and nevi can be camouflaged by using a **white** undercover foundation color. White: Hypopigmentation and depigmentation from skin conditions such as postinflammatory hypopigmentation, congenital pigmentary disorders and vitiligo can be camouflaged by using a **brown** undercover foundation color. Yellow: Yellow facial color from conditions such as solar elastosis, chemotherapy and dialysis can be camouflaged by applying a **purple** undercover foundation color.

Question 41

What is the MOST commonly reported side effect of vismodegib? What are other less common side effects?

Answer 41

The most commonly reported side effect is **muscle spasm**, followed by alopecia and dysgeusia.

Question 42

Botulinum toxin A cleaves which protein to exert its effects?

Answer 42

Botulinum toxins A, C, E catalyze cleavage of **SNAP-25** protein Botulinum toxins B, D, F, and G catalyze cleavage of synaptobrevin (or vesicle-associated membrane protein, VAMP

Question 43

An elderly lady who weighs 110 lbs. What is the maximum amount of 1% lidocaine with 2.5% epinephrine that this patient can receive?

Answer 43

The maximum recommended dosage of 1% lidocaine with 2.5% epinephrine in adults is 7mg/kg. The patient weighs 110 lbs (or 50 kg) which allows her 350 mg (50 x 7) or **35 ml** (1% lidocaine has 10mg of lidocaine perml) of the anesthetic.

Question 44

Paradoxical darkening has been associated with Q-switched ruby, Q-switched alexandrite, and Q-switched Nd:Yag treatment of which three tattoo colors?

Answer 44

Paradoxic darkening of flesh-tone, red, and white tattoo inks with QSRL, Q-switched Nd:YAG, and Q-switched alexandrite lasers has been reported. The tattoo pigments most associated with this phenomenon are iron oxide and titanium dioxide. Ferric sulfide is converted to ferrous sulfate by the laser.

Question 45

Which of the following topical antimicrobials has activity against Pseudomonas? 1. Mupirocin 2. Erythromycin 3. Polymyxin 4. Bacitracin 5. Clindamycin

Answer 45

**Polymyxins** are peptides produced by the organism Bacillus polymyxa. They destroy bacterial membranes by a detergent like mechanism. They are bactericidal against Pseudomonas aeruginosa, Proteus mirabilis, Enterobacter, Klebsiella and Escherichia coli. Since they provide little coverage against gram-positive organisms, polymyxins are often combined with other antibacterial agents to increase their spectrum of activity.

Question 46

Which of the following wound care dressings is the most appropriate choice for a dry, painful wound? 1. Foams 2. Hydrogels 3. Hydrofilms 4. Hydrocolloids 5. Alginates

Answer 46

**Hydrogels** are good for dry painful wounds. Foams are absorptive. Hydrofilms are occlusive, allowing gas and water vapor to permeate. Hydrocolloids are fibrinolytic, cause angiogenesis, inhibit keratinocyte migration, antibacterial increases healing rate, can cause surrounding maceration. Alginates are the most absorptive and are turned into gel by the wound exudate.

Question 47

What is likely to be severed in a lower lip wedge resection and repair?

Answer 47

During this repair, the inferior labial artery is likely to be severed since it courses superficially between the mucosa and the underlying muscle.

Question 48

What is the treatment of choice for DFSP?

Answer 48

Mohs surgery is the treatment of choice for DFSP. The local recurrence rate is 1% with Mohs surgery (vs. 15-50% with wide local excision). Imatinib is approved for unresectable or metastatic disease and targets the COL1A1-PDGFB fusion protein.

Question 49

What rare complications (4) can occur with the use of silver sulfadiazine?

Answer 49

Silver sulfadiazine is most commonly used to prevent infection in second and third-degree burn patients. Rare cases of **leukopenia, neutropenia and kernicterus** have been reported in patients using this topical antibacterial agent. Consequently, silver sulfadiazine should be used cautiously and avoided in infants, nursing mothers and pregnant women. Silver sulfadiazine also has the potential to cause a **hypersensitivity reaction** in patients with sulfa allergy (i.e., **SJS-TEN**).

Question 50

Widespread use of mupirocin over open/damaged skin can cause what?

Answer 50

Nephrotoxicity

Question 51

Bacitracin and polymyxin B can cause what? (2)

Answer 51

ACD and even anaphylaxis in rare cases

Question 52

Which needle shape is most commonly used in cutaneous surgery?

Answer 52

3/8 circle

Question 53

In a patient who is allergic to paraphenylinediamine, which of the following anesthetics should be avoided? 1. Bupivicaine 2. Etidocaine 3. Mepivicaine 4. Prilocaine 5. Benzocaine

Answer 53

Paraphenyelenediamine is a common allergen found in permanent hair dyes. Individuals who are allergic to paraphenylendiamine may also have allergic reactions to **ester anesthetics, like benzocaine** (though true allergies to local anesthetics are rare). Other crossreactants to paraphenyelediamine include the preservative parabens, PABA, sulfonamides, and thiazide diuretics.

Question 54

True or false: patients with mitral valve prolapse require prophylactic antibiotics.

Answer 54

False Patients with mitral valve prolapse without valvular insufficiency or regurgitation noted on ultrasound are at no higher risk for bacterial endocarditis than the general population and, therefore, do not require preoperative antibiotics. According to the AHA, those patients who are at high risk for bacterial endocarditis and require preoperative antibiotics include those with prosthetic cardiac valves, previous bacterial endocarditis, complex cyanotic congenital heart disease, and surgically constructed systemic-pulmonary shunts. Moderate risk patients include those with mitral valve prolapse with regurgitation, acquired valvular dysfunction, and hypertrophic cardiomyopathy.

Question 55

What is the recommended excision margin for a melanoma with a Breslow depth of 0.9 mm?

Answer 55

1.0 cm The recommendation for a margin excision for in situ melanomas is 0.5cm (not including lentigo maligna forms). Margin excision for a melanoma up to 1mm in thickness is 1.0cm. Thickness between 1.01-2mm requires a 1-2cm surgical margin, and \>2cm is needed when the tumor thickness reaches 2mm.

Question 56

What component of a laser informs its wavelength?

Answer 56

Laser light is monochromatic light that is emitted at a single wavelength. The wavelength of the laser is determined by the **medium** in the optical cavity of the laser through which the light passes. The medium may be solid, liquid or gas.

Question 57

What tattoo ink is the most difficult to treat with laser?

Answer 57

**White ink (titanium dioxide)** is composed of many different colors and, as such, reflects the colors of most laser light instead of absorbing them. This property makes white tattoos difficult to treat by most commercially available lasers.

Question 58

Which topical antiseptic works via denaturation of proteins?

Answer 58

**Alcohols** exert their antimicrobials effect via **denaturation of proteins**. Chlorhexidine, hexachlorophene, and triclosan disrupt the microbial cell membrane. Iodine and iodophores work via oxidation/substitution for elemental form of iodine, thereby precipitating proteins.

Question 59

What can be added to a TCA 20% peel to boost its effectiveness for treatment of melasma?

Answer 59

When comparing the TCA alone-treated patients to patients treated with the combination TCA and **5% ascorbic acid** (vitamin C) peel, a significant reduction in pigmentation was noted in the combination peel patients.

Question 60

True or false: Moderate to severe obesity are contraindications to liposuction

Answer 60

True Liposuction is not intended for weight reduction. **Moderate obesity is relative contraindication, while severe obesity is an absolute contraindication.** The upper limit of fat extraction in one setting is 4500-5000mL, according to American Academy of Dermatology guidelines. Beyond this, fluid shifts can occur, resulting in cardiovascular compromise. Liposuction does not improve the appearance of cellulite.

Question 61

Which are the solid media lasers? (5) Liquid media? (1) Gas media? (3)

Answer 61

Solid media lasers include **alexandrite, KTP, ruby, Nd:YAG, diode.** Liquid media is found in the **pulsed dye laser**. Gas media is used in **argon, carbon dioxide, and krypton.**

Question 62

A patient comes in for endovenous laser ablation for varicose veins. You choose a 1320nm or 1450 nm laser. Which is the target chromophore for these lasers?

Answer 62

810–1064 nm laser (targetting more Hb), as well as 1320, 1440 and 1500 nm lasers (targetting more water) can be used in Endovenous Laser Ablation. The latter wavelengths target tissue **water** within the vein wall, causing fibrosis, results in a more controlled, and uniform heating. The absorption of water increases above 1000nm. Deoxygenated hemoglobin is the main chromophore of the 810- and 980-nm lasers. Oxygenated hemoglobin peaks in absorption between 400-600nm (vascular lasers).

Question 63

True or false: Caucasian women tend to get cellulite more than Asian women.

Answer 63

True

Question 64

In the 60-degree z-plasty technique, the length of the scar length is increased by what percentage?

Answer 64

A Z-plasty is a transposition flap used to treat wound contractures and scars. It is performed to decrease tension on a wound, change the orientation of a scar, and improve overall scar appearance. **A 60-degree Z-plasty will yield a 75% increase in scar length** and a 90-degree change in scar direction. A 45-degree Z-plasty will yield a 50% increase in scar length, and a 30-degree Z-plasty will yield a 25% increase in scar length.

Question 65

The pain associated with Botulinum A Exotoxin injection is attributed to what?

Answer 65

In a double-blind, randomized controlled study, investigators found that botulinum A exotoxin reconstituted with **preservative-containing saline** less painful than with **preservative-free saline**.

Question 66

Which topical vitamin has been shown to decrase teh severity of laser-induced purpura, although its mechanism is unclear.

Answer 66

Topical vitamin K

Question 67

Treatment of acne scarring would be most effective with which modality? * PDL * IPL * PDT * Radiofrequency * Q-switched 1064 nm Nd:YAG laser

Answer 67

Treatment with the nonablative **1064-nm Q-switched Nd:YAG** provides significant improvement in **skin topography** in patients with atrophic acne scars. The further improvements that are seen at 6-month follow-up suggest that dermal remodeling is a process that continues long after treatment.

Question 68

Which of the following is FALSE about MMS? * Complication rate is less than 1-3% * No deaths have been reported as a complication * Infection rates do not differ by use of nonsterile versus sterile gloves * Wrong site surgery is most common reason for legal claims against Mohs surgeons * Photography improves accuracy compared to clinical notes and diagrams alone

Answer 68

Trick question!! These are ALL TRUE!

Question 69

What is the FDA-approved recommendation for the use of imiquimod (Aldara) for superficial BCC?

Answer 69

5 times a week for 6 weeks

Question 70

What is the name of this phenomenon? What are at least two reasons that this may have occurred?

Answer 70

**Inadequate undermining and/or oversized flap** The arrow is pointing to an area of a **trapdoor deformity** which presents as *pincushioning* or a protuberant appearance of a flap. Commonly it presents 3-6 weeks post-op and is very common on the nose. It is likely due to circumferential contraction of the flap causing the flap to buckle.

Question 71

True or false: 1064 nm Nd:YAG (long-pulsed) can be used for a venous lake of the lip.

Answer 71

True

Question 72

Which of the following cosmetic injectables does not illicit an inflammatory response? * Hydroxylapatite (Radiesse) * Polymethylmethacrylate (Artecoll) * Silicone * Zyplast (collagen) * Poly-L-lactic acid (Sculptra)

Answer 72

**Radiesse** is an injectable, biodegradable filler composed of calcium hydroxyapatite microspheres. It is a **normal constituent of bone and is therefore biocompatible**.

Question 73

What is "ChloraPrep" made out of? (2)

Answer 73

Chlorhexidine gluconate and isopropyl alcohol

Question 74

What is collimation mean?

Answer 74

Collimation refers to the parallel nature of light beams that make a laser focused on even small spot sizes. Monochromicity refers to a single wavelength, coherence refers to light traveling in phase.

Question 75

What would be the antibiotic of choice for a patient s/p ear helical rim advancement flap after MMS? * Dicloxacillin * Cephalexin * Erythromycin * Ciprofloxacin * TMP-SMX

Answer 75

**Ciprofloxacin** would be the antibiotic of choice for this patient because it is effective against Pseudomonas species. None of the other options would cover Pseudomonas

Question 76

When do hair grafts start to grow after implantation?

Answer 76

The use of follicular-unit grafts, which contain one to four hair follicles, represents the advancement in both surgical technique and aesthetic outcome in the field of hair transplantation. The grafted hair follicles typically begin to grow **within 1-3 months of implantation** and are expected to survive for the individual's lifetime. Initial shedding of hairs from grafts may occur.

Question 77

What are the alpha-hydroxy acids? What is an example of a beta-hydroxy acid?

Answer 77

**Lactic acid, citric acid, glycolic acid, and tartaric acid** are all alpha-hydroxy acids. **Salicylic acid** is a type of beta-hydroxy acid.

Question 78

What are the ingredients in a Baker-Gordon peel? (4) What are the ingredients in Jessner's solution? (4)

Answer 78

* Baker-Gordon peel: phenol, croton oil, water, and septisol (hexachlorophene) * Jessner's solution: salicylic acid, resorcinol, lactic acid, and ethanol

Question 79

What are risk factors for post-transplant skin cancer? What chemotherapy is protective against skin cancer?

Answer 79

Post-transplant skin cancer is common, with elevated risk imparted by **increased age, white race, male sex, and thoracic organ transplantation**. **Sirolimus (mammalian target of rapamycin inhibitor)** has shown evidence of decreasing the risk of post-transplantation skin cancer incidence.

Question 80

Which type of collagen is the first to be deposited in a healing wound?

Answer 80

Collagen III then → collagen I This occurs during "proliferative phase" of wound healing Collagen type III is the predominant collagen in early wound healing.

Question 81

The Shaw scalpel is used for what?

Answer 81

The Shaw scalpel provides the ability to cut through tissue with minimal blood loss. This instrument employs an **electronically heated metal cutting blade (electrocautery)** that heats up while it cuts through tissue, and coagulates fine vessels when they are divided. This instrument has been used frequently for treatment of rhinophyma and in parotid gland surgeries.

Question 82

Which part of the eye is most likely to be damaged to exposure to a pulsed dye laser?

Answer 82

The pulsed dye laser operates at 585-nm and targets hemoglobin as a chromophore. It can pass through the cornea and **damage choroidal and retinal vasculature**. Several pigment-specific lasers (eg, ruby, alexandrite, Nd:YAG) may also damage the retina by targeting the retinal pigment. Laser-induced eye damage is related to the chromophore of the laser. The lasers that target water damage the cornea and sclera.

Question 83

What is USP regarding sutures?

Answer 83

Sutures are classified according to the United States Pharmacopeia (USP) criteria. This classification system specifies the **diameter of a given suture material that is required to produce a certain tensile strength**. The smaller the cross-sectional diameter of a suture material, the higher the USP number that is assigned. Thus, 4-0 Vicryl will have greater tensile strength and a larger cross-sectional diameter than 5-0 Vicryl.

Question 84

A patient recently underwent submental injections of deoxycholic acid (Kybella). One day later, she noticed an inability of her right lip depressors to pull her lip downward and laterally, particularly when smiling. What is the next best step?

Answer 84

Kybella (deoxycholic acid) is an FDA-approved treatment for injection into the submental area. Cases of marginal mandibular nerve injury manifesting as an asymmetric smile or facial muscle weakness were reported in 4% of subjects in clinical trials. All cases resolved spontaneously within a median of 44 days. It should not be injected into, or in close proximity to, the marginal mandibular branch of the facial nerve. **Watchful waiting** is therefore recommended as the next step.

Question 85

True or false: The amino acid homocysteine promotes skin aging.

Answer 85

True Homocysteine is a sulfhydryl-containing amino acid produced during the conversion of methionine to cysteine. **Homocysteine can promote defects in fibrillin-1 and stimulate matrix metalloproteinase production, leading to collagen and elastic fiber degradation.** Homocystinuria, caused by a deficiency in cystathionine beta-synthase, presents with osteoporosis, thin skin, and striae.

Question 86

What are two lasers of choice for the treatment of rhinophyma?

Answer 86

The **carbon dioxide laser is a 10600 nm laser** that can be used to treat rhinophyma. The advantage of the carbon dioxide laser over steel or dermabrasion is that the laser is relatively bloodless. The **Er:YAG (2940 nm)** can also be used to treat rhinophyma. The PDL is the laser of choice for vascular lesions such as port wine stains, telangiectasias, superficial hemangiomas, and **erythematotelangiectatic rosacea.**

Question 87

Why is tungsten carbide used for scissors with gold handles?

Answer 87

Tungsten carbide is believed to be a **harder more durable material** that allows for **better grasping** of the needle. Tungesten carbide inserts are **last longer** and typically offer a **better grip**. Needle holders with tungsten carbide jaws usually have gold-plated handles.

Question 88

What is a complication of Thermage treatment?

Answer 88

**Lipoatrophy** Thermage (ThermaCool) is a nonablative radiofrequency-based system which uses volumetric heating to induce tightening of the skin and dermal remodeling. Lipoatrophy is a late-occurring potential complication of this technology.

Question 89

How does tissue tensile strength vary at the following time points after surgery: * 3 weeks * 6 weeks * 6 months * 1 year

Answer 89

* 3 weeks → 20% * 6 weeks → 40-50% * 6 months → 70% * 1 year → 80%

Question 90

A patient who had liposuction 5 weeks ago presents with multiple firm nodules at the cannula insertion sites. You suspect the diagnosis is: * Foreign body granuloma * HSV infection * Organized hematoma * Mycobacterial infection * Cold panniculitis

Answer 90

**Atypical mycobacterial infections** are occurring with increasing frequency after cosmetic surgery procedures. These infections typically occur 4-14 weeks after a procedure as a late-occurring complication. Firm nodules at the treatment site or dehiscence of a previously healed wound may be presenting signs of atypical mycobacterial infection.

Question 91

True or false: A patient with skin type III receiving ablative CO2 resurfacing will have reduced risk of hyperpigmentation if they begin hydroquinione 2 weeks prior to the procedure

Answer 91

False The 1999 paper by West and Alster demonstrated that pretreatment with hydroquinone did not reduce the risk of hyperpigmentation after CO2 laser resurfacing. **HOWEVER, Hydroquinone does reduce post-inflammatory hyperpigmentation if it does develop after laser resurfacing.**

Question 92

Which has greater initial tensile strength: polydioxanone (PDS) or polyglactic 910 (Vicryl)?

Answer 92

Polydioxanone (PDS)

Question 93

Imiquimod is an immunomodulator which induces the production of which five cytokines that are involved in cell-mediated immunity?

Answer 93

These cytokines include interferon-alpha, **interferon-gamma**, interleukin-1, interleukin-10 and tumor necrosis factor-alpha.

Question 94

The nasolabial two stage flap depends on which artery for flap survival?

Answer 94

Angular artery provides blood supply for the nasolabial transposition flap.

Question 95

What are the best three superficial chemical peels for the treatment of melasma?

Answer 95

Tricholoracetic acid (TCA) 10-25%, Jessner's solution, and Glycolic acid 20-70% are the best three superficial peel options for treatment of melasma.

Question 96

Which of the following complications has been reported with infraorbital injections of Botox? * Nystagmus * Blindness * Festooning * Astigmatism * Photophobia

Answer 96

**Festooning** of the lower eyelid is a recently reported complication of infraorbital Botox injections. The affected patient had a prior lower lid blepharoplasty which likely weakened the orbicularis oculi muscle. The author postulates that festooning resulted from further muscle weakness due to Botox treatment. See asterisks in photo for example of lower eyelid festooning. Dots represent a separate finding called dermatochalasis, which is not related.

Question 97

Which TLR is induced and what cytokines are upregulated by imiquimod (Aldara)?

Answer 97

It induces **toll like receptor (TLR) 7** and the production of Th-1 cytokines including **tumor necrosis factor (TNF)-α , interferon (IFN)-γ , interferon (IFN)-α , and interleukin (IL)-12**, leading to stimulation of a cell-mediated immune response.

Question 98

How much larger should a full thickness skin graft be compared with the surgical defect it is being using to fill?

Answer 98

Graft should be up to 25% larger than the defect

Question 99

To avoid injury of CN VII, undermining in the region of the temple should be performed at which anatomic level? * DEJ * Reticular dermis * Subcutaneous fat * Below the superficial fascia (SMAS) * Above the frontalis muscle

Answer 99

**Subcutaneous fat** In region of the temple, temporal branch of CN VII lies in superficial fascia → undermine in **superficial subcutaneous fat**

Question 100

Which of the following cosmetic injectables has the longest duration of action? * Onabotulinumtoxin A (Botox) * Poly-L-lactic acid (Sculptra) * Restylane (hyaluronic acid) * Cosmoderm (collagen) * Juvederm (hyaluronic acid)

Answer 100

**Sculptra** (called New-Fill outside of the US) is a biodegradable filler composed of **poly-L-lactic acid**, the same material used in absorbable sutures. Polymerized poly-L-lactic acid augments soft tissue by stimulating the production of collagen. Preliminary studies have demonstrated longevity of the filler at two years post-treatment. Botox lasts 3-6 months. HA fillers last 6-12 months. Human collagen (e.g., Cosmoderm) lasts up to 12 months but is not commonly used at this point.

Question 101

What nerve gives sensation to the nasal tip and columella?

Answer 101

**External nasal nerve**, a terminal branch of the **anterior ethmoidal nerve** (of CN V1)

Question 102

Reticulate erythema is a side effect seen with which treatment? * Mesotherapy * Sclerotherapy * Diode laser * Cryotherapy * PDL

Answer 102

**Diode laser (800 nm)** Reticulate erythema is a recently-reported side effect of diode laser treatment. _High energy fluences_ and a _history of chilblains_ are believed to be predisposing risk factors. Laser treatment should be discontinued at the first sign of this complication.

Question 103

What tattoo pigment is responsible for most eczematous and lichenoid reactions?

Answer 103

**Mercuric sulfide** Lichenoid tattoo reactions are not as common as eczematous reactions, both of which are most commonly caused by mercuric sulfide.

Question 104

What is the most common genetic alteration seen in mucosal melanomas? What about in uveal melanomas and blue nevi?

Answer 104

Mucosal melanomas → KIT Uveal melanomas and blue nevi → GNAQ

Question 105

Where does the temporal branch of CN VII run with respect to the ear and eyebrow? Where is the "danger zone" for the nerve?

Answer 105

Temporal nerve runs **0.5 cm below tragus to 1.5 cm above lateral brow** The "danger zone" occurs within a 2 cm box from **anterior hairline and lateral eyebrow**, where it runs beneath the SMAS. Injury to this nerve results in unilateral forehead paralysis, ipsilateral forehead flattening, and eyelid ptosis.

Question 106

Which tattoo pigment is most likely to cause an allergic contact dermatitis?

Answer 106

Red

Question 107

Which ocular structure is at most risk of injury from an Er:YAG laser?

Answer 107

**Cornea** Lasers targeting water (i.e., CO2 and Er:YAG) → damage the cornea Lasers targeting hemoglobin or pigment → damage retinal pigment or vasculature

Question 108

What structure is being lifted by the dissecting probe? * Angular artery * Transverse facial artery * Buccal nerve * Mental nerve * Superior labial artery

Answer 108

The identified structure is the angular artery. After forming the superior labial branch, the facial artery becomes known as the angular artery. The pictured structure is wider caliber vessel, thus not a nerve. The superior labial artery and the transverse facial artery have lateral-medial orientations as opposed to the caudal-cephalad orientation of the angular artery/facial artery (see photo).