Flashcards in Derm Deck (76):
what is the most common subcutaneous neoplasm
what is the most common tumor diagnosed in the US?
Basal cell carcinoma
biggest risk factor for BCC
UV exposure, during adolescence
Most common form of BCC
nodular form. pearly nodules with rolled edges. Rodent ulcer.
Treatment options for BCC
Moh's surgery, Excisional surgery, Cautery and destruction or radiation
The definitive treatment for non-morpheform BCC lesions
Excision surgery with 4 mm margins and extension into subcutaneous tissue
treatment of choice for morpheaform, recurrent and infiltrative BCC
cautery and destruction for BCC
should never be for facial lesions and should only be used for patients that are somehow not candidates for excision or mohs
SCC that tend to be slower growing
develop from actinic keratosis
SCC that tend to be more aggressive
develop from Bowen disease, erythroplasia of Queyrat, chronic radiation dermatitis, scars and chronic ulcers. Also lesions that develop from normal appearing skin of the lips, genital and anal area.
Sentinel lymph node biopsy- maps the first node basin that any disease would travel to if it were metastatic. Used for high risk SCC > 2mm or for MM > 1 cm Palpable lymph node is a contraindication for SNLB.
High risk tumors
> 2cm in diameter and/or involvement into the subcutateous tissue
Indications for Moh's surgery
nail bed lesions, verrucous carcinomas, invasive lesions, poorly differentiated times and at sites where cosmesis is critical
increases risk of developing Malignant melanoma x2
10+ tanning bed sessions as an adolescent/young adult
most common subtype of Malignant Melanoma
Superficial Spreading (70%). Not found on the hands or feet
Skin lesion diameter that is concerning
> 6 mm
margin size for MM tumors
margin size for MM tumors 1-2 mm
margin size for MM tumors 2-4 mm
margin size for MM tumors > 4mm
margin size for MM in-situ tumor
Factors affecting the severity of a burn
The degree of heath, length of time in contact with her, and what part of skin is affected
1st degree burn
partial thickness, epidermis only. Is dry, red and Painful.
treatment for a 1st degree burn
cool moist gauze, fans, and OTC topicals
2nd degree burn
partial thickness burn that causes the epidermis to separate. These are red, wet and very painful.
3rd degree burn
full thickness burn into the corium and fat layers. These are leathery, dry and insensate. Granulation occurs and skin is friable. Will contract and be hypertrophic
admission criteria for a burn
airway compromise, need fluid resuscitation, > 10-15% TBSA, unable to take PO, burn to face, ears, hands, genitals, feet, suspected abuse, skin grafting indicated
Burn unit transfer criteria
2nd or 3rd degree burns that are > 10%TBSA in pts 10-50 yo, or burns that are >20%TBSA in other age groups. Burns that involve the face, hands, feet, genitals, perineum or major joints. any 3rd degree burn > 5%TBSA. Electrical and chemical burns apply and any case that involves an inhalation injury.
Fluid replacement formula for burn patients. mL of LR to give = 4mL x kg body weight x % burn. This is in addition to maintenance fluids. The first 1/2 of estimated volume to supplement is given in 1st 8 hrs, and the remainder is spread out over 16 hours.
broad spectrum gr+ and - coverage for burn wounds that is only moderately affective in penetrating an eschar. Application is typically painless. When used over large burns pts may develop transient leukopenia- usually self limiting.
Aqueous silver nitrate 0.5%
Topical medication for burns, has broad spectrum coverage including fungal coverage but is prone to leaching electrolytes
topical medication for burns that has broad spectrum coverage and is best for penetrating burn eschar
Circumferential and 3rd degree burns pose specific risk of
compromising circulation and complicating breathing because of contractors that form
cutting and releasing the tension of the scar eschar. Old way to do it on the trunk was the checkerboard pattern. Now we do make long axillary lines down to subcostal margin and then connect along the bottom of the abdomen. Bivalve cuts medially and laterally is indicated for limb escharotomy
Risks associated with electrical burns > 500 volts
Compartment syndrome, cardiac arrhythmia, myoglobinuria
Suspect inhalation injury if
burn exposure was in a small enclosed space, facial burns, singed nasal hairs, carbon debris in mouth, pharynx or sputum
adheres to the would coagulum and provides good pain control
Split thickness allograft
vascularizes and proves durable temporary closure of wounds
provide vapor and bacteria barrier and absorbs wound exudate
provide vapor and bacteria barrier and allow drainage
AlloDerm R semipermeable membrane
cell-free, allogenic human dermis. Requires immediate thin overlying autograft
IntegraR semipermeable membrane
Is a scaffold for neodermis- requires a delayed thin autograft
Taking a skin graft
Take skin along the dermatome, make sure it is thin enough so that the donor site is able to heal, and make sure the bleeding points are close together to ensure adequate blood supply.
Can uses a skin graft if
the wound has adequate vascular supply, there is no infection, and hemostasis is assured. Points like color matching, contour, durability, and donor morbidity need to also be considered.
Common sites for graft harvesting
anterior thigh and buttocks
Full thickness graft
Takes full layer of epidermis and dermis. Goes down to the subq.
Thick split-thickness graft
Takes full epidermis + 2/3 of the dermis
Intermediate Split-thickness graft
Takes full epidermis + 1/3 of the dermis
Thin split-thickness graft
takes epidermis only
most widely used method for obtaining skin graft
Electric or air powered dermatomes- because of their reliability and ease of operation
To ensure survival of the graft
make sure there is adequate vascularity of the recipient bed, make sure there is complete contact between the graft and the bed, and make sure the graft-bed unit is immobilized and that it is relatively abacterial
care of a meshed skin graft
should be covered for 24-48 hrs. often covered with Xeroform gauze, but can also use a wound vac or bolster dressing. Dressings can be left on for 5-7 days if the grafted wound was free from infection
Advantages of a split thickness skin graft
contract less, more resistant to surface trauma, more similar to normal skin compared to thinner grafts. Aesthetically marginally acceptable
Disadvantages of split-thickness skin graft
have a higher fail rate of taking to the recipient site, donor sites are slower to heal compared to thinner grafts, and donor sites heal with more scarring compared to thinner grafts
advantages of meshed split thickness skin graft
can be placed in an irregular and even contaminated wound bed, fewer hemostasis complications, can get more coverage from less skin
disadvantages of meshed split thickness skin graft
poor cosmesis- alligator hide look
advantages of full thickness skin grafts
these are the most aesthetically desirable for the recipient because they have the least amount of contracture and have the greatest ability to withstand trauma.
disadvantages of full thickness skin grafts
the size and number of available donor sites is limited. the donor site has to heal by primary intention and will have a scar. Also, conditions at the recipient site must be optimal for a successful transplant
Best donor sites for full thickness skin grafts
eyelid skin, post-auricular, supraclavicular, antecubital, inguinal and genital areas. Areas of thin skin are best.
indications for using Integra biologic skin substitute
area over a tendon, where simple skin graft alone would not suffice
random pattern skin flap
consists of skin and subq tissue and has peripheral artery blood supply, but in no particular relation or orientation. This is the least reliable type of flap but is commonly used. Can rotate these flaps. The ratio of length to width cannot exceed 1.5 : 1 (unless the flap is cut from the face or scalp).
axial pattern skin flap
these flaps have very well defined blood supply running along the long axis of the flap- can be very long and skinny. Most common axial flaps are deltopectoral and forehead flaps
muscle and musculocutaneous flaps
consist of skin and underlying muscle- these flaps have revolutionized reconstructive surgery. skin over major parts of muscles are supplied by one primary axial vessel- this entire area can be circumscribed and relocated to an area in need. These flaps are best for wound areas caused by radiation, osteomyelitis or areas at high risk of infection.
latissimus dorsi muscle flap
supplied by thoracodorsal vessels and often used in mastectomy reconstruction
pectorals major muscle flap
used to cover defects in the sternum, neck and lower face. Supplied by subclavian artery and internal mammary artery.
tensor fasciae latae muscle flap
can be used to reconstruct the lower abdominal wall, to cover defects from ulcers of the pubis and groin, and is the method of choice for covering greater trochanteric pressure ulcers. supplied by lateral femoral circumflex a.
rectus femoris muscle flap
used for reconstruction of lower abdominal wall and for ulcers in the pubis and groin. has a shorter arc of rotation but is more robust of a flap compared to the tensor face latae. Supplied by the profunda femoris a and superficial femoral aa.
rectus abdomens myocutaneous flap
TRAM flaps are the workhorse for autologous tissue breast reconstruction. Supplied by epigastric arcade composed of deep superior and inferior epigastric aa
trapezius muscle flap
covers defects in the neck, face and scalp. supplied by transverse cervical aa
temporalis muscle flap
commonly used to cover orbital defects, supplied by temporal aa
Gluteus maximus muscle flap
used to cover pressure sores, supplied by superior and inferior gluteal aa
Gracilis muscle flap
supplied by metal femoral circumflex aa, and can be used for ischial pressure sores and vaginal reconstruction
gastrocnemius muscle flaps
used to cover the knee an anterior tibia, and is supplied by sural aa
free skin flaps
microvascular surgery is used to remove a flap of skin and reconnect its blood supply with the recipient blood supply.
Deep inferior epigastric perforator flap- a free flap that is commonly used in breast reconstruction