Ch. 3 Skin: Wounds, Infections, and Burns; Hands; Plastic Surgery

Question 1

A 68 y/o woman presents with a pigmented lesion on the trunk. Upon further examination, the lesion has an irregular border, darkening coloration, and raised surface. An incisional biopsy is performed and confirms a melanoma with a thickness of 0.5 mm. The patient is scheduled for a wide local excision of the melanoma in the OR. Which of the following is the smallest margin recommended for excision?

a. 3 mm
b. 5 mm
c. 1 cm
d. 2 cm
e. 5 cm

Answer 1

c. 1 cm

The appropriate margin for wide excision of melanomas is dependent on the depth of the lesion. For thin lesions, less than or equal to 1 mm in depth (thickness), a 1 cm margin is adequate. For intermediate lesions (1-4 mm thick), a 2 cm margin is recommended, and thick (>4 mm) lesions benefit from a 2- to 3- cm margin of excision.

Question 2

A 25 y/o woman presents with a benign nevus on her R upper arm. She desires removal and undergoes a clean incision and then closure of the incision without complication. With regard to the healing process, which of the following cell types are the first infiltrating cells to enter the wound site, peaking at 24 to 48 hrs?

a. Macrophages
b. Neutrophils
c. Fibroblasts
d. Lymphocytes
e. Monocytes

Answer 2

b. Neutrophils

Wound healing:

1. Inflammation
   
   1. Rapid influx of neutrophils –> followed about 2 days by mononuclear cells (macrophages phagocytose debris but also secrete TNF, PDGF, FGF)
2. Proliferation –> angiogenesis and collagen formation (fibroblasts which enter at day 3 continue to proliferate with increasing collagen deposition)
   
   1. Type III collagen (elastic fibrils) predominates for 2-3 weeks
   2. Replaced by Type I collagen (rigid fibrils)
3. Remodeling
   
   1. Collagen deposition and degradation reach a steady state
   2. May continue up to a year

Question 3

A 3 y/o boy is brought to the ER after spillage of bleach onto his lower extremities. He is diagnosed with a chemical burn and all involved clothing are removed. In addition to resuscitation, which of the following is the most appropriate initial mgmt of this pt?

a. Treatment of the burn wound with antimicrobial agents
b. Neutralize the burn wound with weak acids
c. Lavage of the burn wound with large volumes of water
d. Wound debridement in the OR

Answer 3

c. Lavage of the burn wound with large volumes of water

Attempts to neutralize alkali with weak acids are not recommended because the heat released by neutralization rxns induces further injury

Operative debridement is indicated for particularly strong bases and takes place after resuscitation and lavage with large amounts of water

Question 4

A 35 y/o man with new diagnosis of Crohn disease presents with rapidly enlarging painful ulcerations on the lower extremities. Cultures of the lesion are negative, and skin biopsy reveals no evidence of malignancy. Which of the following is the most appropriate tx option?

a. Surgical debridement of the wound with skin grafting
b. Local wound care with silver sulfadiazine
c. Topical corticosteroids
d. Systemic steroids and immunosuppresants

Answer 4

d. Systemic steroids and immunosuppresants

The pt has pyoderma gangrenosum, which is a rare cause of cutaneous ulcerations that can be associated with IBD. Systemic steroids and immunosuppressants such as cyclosporine = mainstay of tx

Question 5

Proper initial treatment for frostbite?

a. Debridement of the affected part followed by silver sulfadiazine dressing
b. Administration of corticosteroids
c. Immersion of affected part in water at 104-111 F
d. Rewarming of the affected part at room temperature

Answer 5

c. Immersion of affected part in water at 104-111 F

Question 6

A 63 y/o man with hx of poorly controlled diabetes presents with R leg swelling and pain. The patient denies trauma to the leg and reports it was normal yesterday. Exam of the R lower extremity is significant for extreme tenderness to palpation, erythema, and edema extending up to the knee.

X-ray of the R leg shows tissue swelling without gas or osteomyelitis. The patient’s vital signs are normal and he is started on broad-spectrum IV abx and insulin. An hr later, the pt’s HR increases to 126 bpm and erythema has progressed to the thigh with new blister formation on the leg. Which of the following is the most appropriate next step in mgmt?

a. Repeat x-ray of R lower extremity
b. CT scan of the R lower extremity
c. MRI “ “
d. Bone scan “ “
e. Immediate surgical intervention with incision and direct visualization of potentially infected tissue

Answer 6

e. Immediate surgical intervention with incision and direct visualization of potentially infected tissue

Necrotizing soft tissue infection –> rapid progression of erythema, bullae formation, tachycardia mandates immediate surgical intervention

Question 7

A 65 y/o woman presents with a 1-cm lesion with a pearly border on her nose, and punch biopsy is consistent with BCC. She is scheduled to undergo Mohs surgery. Which of the following is a benefit of Mohs surgery over wide local excision?

a. Mohs surgery results in a smaller cosmetic defect while obtaining negative margins circumferentially.
b. Mohs surgery offers a shorter operating time.
c. Mohs surgery can be performed on many different types of skin cancers.
d. Mohs surgery results in less recurrence and metastases.
e. Mohs surgery does not depend on intraoperative evaluation of specimen margins with frozen sections.

Answer 7

a. Mohs surgery results in a smaller cosmetic defect while obtaining negative margins circumferentially.

Good for BCC and SCC on face

Question 8

Define

• Erythroplasia of Queyrat
• Bowen disease
• Marjolin Ulcer

Answer 8

All SCC

• Erythroplasia of Queyrat: SCC tumors specific to penis
• Bowen disease: SCC in situ
• Marjolin Ulcer: SCC due to thermal injury/burn

Question 9

What are the three main topical agents used on burn wounds and their complications?

Answer 9

1. Silver nitrate
   
   1. Electrolyte abnormalities (hyponatremia, hypokalemia, hypocalcemia, hypochloremia)
   2. Methemoglobinemia
2. Silver sulfadiazine
   
   1. Neutropenia
3. Mafenide acetate
   
   1. Metabolic acidosis 2/2 inhibition of CA

Question 10

A 54 y/o man sees you because of a growth on his lower lip. He smokes tobacco, has a fair complexion, and works outdoors. The biopsy report confirms carcinoma. Which of the following is the most common dx for tumors involving the lips?

a. SCC
b. BCC
c. Malignant melanoma
d. Keratoacanthoma
e. Verrucous carcinoma

Answer 10

a. SCC of the lip is the most common malignant tumor of the lip and constitutes 15% of all malignancies of the oral cavity. The majority of lip malignancies present on the lower lip (88-98%).

BCC occurs less frequently and on upper lip

Question 11

A 60 y/o diabetic man undergoes incision and drainage of an infected boil on his back. The wound is left open and packed daily. Week by week, the wound grows smaller and eventually heals. Which of the following terms describes the method of wound closure by the patient?

a. Primary intention
b. Secondary intention
c. Tertiary intention
d. Delayed primary closure
e. Delayed secondary closure

Answer 11

b. Secondary intention

There are 3 types of wound closures: primary, secondary, tertiary intention

• Primary: simple suture, skin graft placement, flap at the end of the surgical procedure
• Secondary: leave wound open –> woulnd heals by re-epithelization –> contraction of wound
• Tertiary (aka delayed primary).. first treat with abx, debride, negative pressure dressing until infection is controlled

Question 12

A 67 y/o man presents to his PCP with a 1-cm skin lesion on his L forearm. On exam, it has a waxy appearance with rolled, pearly borders surrounding a central ulcer. Which of the following is the most appropriate mgmt of this pt?

a. Mohs
b. Curettage of the lesion
c. Laser vaporization of the lesion
d. Surgical excision

Answer 12

d. Surgical excision

The patient’s lesion has a classic appearance of BCC (most common type of skin cancer)

Given size and location, surgical excision is most appropriate

Mohs is reserved for managing tumors in aesthetic areas such as the eyelid, nose, cheek

Question 13

What type of lower extremity lesion? Tx?

1. A 43 y/o man with a painless ulceration over the left medial malleolus with surrounding brawny induration
2. A 69 y/o man with a hx of diabetes mellitus with pain in the balls of his feet at night with an ulcer over the lateral aspect of his R 5th toe
3. A 52 y/o woman with a hx of diabetes mellitus with an ulcer on the plantar surface of her R heel

Answer 13

1. A 43 y/o man with a painless ulceration over the left medial malleolus with surrounding brawny induration
   
   1. ​Venous stasis ulcer
      
      1. Tx: leg elevation, compression stockings, local wound care
2. A 69 y/o man with a hx of diabetes mellitus with pain in the balls of his feet at night with an ulcer over the lateral aspect of his R 5th toe
   
   1. ​Ischemic ulcer
      
      1. _​_Tx: urgent eval for LE revascularization
3. A 52 y/o woman with a hx of diabetes mellitus with an ulcer on the plantar surface of her R heel
   
   1. ​Diabetic ulcer
      
      1. _​_Tx: optimize pt’s blood sugars, protective shoe wear, debridement of necrotic tissue