SKIN EXAM & DERM PROCEDURES PPT Flashcards
GOAL OF SKIN EXAM
- determine general skin color & number of nevi
- screen for melanoma: look for lesions with ABCDE
ABCDEs of moles
Asymmetry Border irregularities Color variation Diameter > 6mm Evolution (of color, shape, symptoms) or Enlargement
hand held microscope used by dermatologists
dermatoscope
SKIN MAPPING / MOLE MAPPING
Another less commonly used method of following change with pigmented lesions is mole mapping. With this technology, suspicious moles can be digitized with dermatoscopes cameras and reimaged at three- to six-month intervals to determine if any changes in characteristics have occurred in this time
indications for a biopsy
- All suspected neoplasms
- All bullous disorders
- To clarify a diagnosis when a limited number of entities are under consideration
BEFORE DOING THE BIOPSY
Make sure patient has no absolute contraindications
Pt needs to be asked about allergies/reactions to topical antibiotics, local anesthetics and tape
Need to know if pt has a bleeding disorder or is on aspirin or warfarin
o If on aspirin—OK to biopsy; use pressure dressing
o If on warfarin—refer to dermatologist
Nerves & Vessels run in the _____________ plane; so punch biopsies can be safely performed if they are stopped at the interface of ______ & __________
subcutaneous fat
dermis & subcutaneous fat
BIOPSY DANGER ZONES
Areas overlying highly vascular structures
Areas associated with exit points of superficial motor nerves
1) lateral mandible = exit point of marginal mandibular nerve
2) posterior lateral neck = exit point of spinal accessory nerve
3) temple = temporal branch of facial nerve
SITE SELECTION FOR BIOPSY
o Inflammatory lesions - biopsy those with characteristic inflammatory changes (ex: erythema) first
o Blistering diseases - biopsy only the newest vesicles or blisters, ideally within 48 hours. Remove vesicles intact with adjacent normal skin when possible (include normal skin, border, and inner vesicle if possible for pathologist to compare)
o Nonbullous lesions
include maximal lesional skin & minimal normal skin
lesions that are between 1-4mm = excise completely
for larger lesions = biopsy the edge, the thickest portion, or the area that is most abnormal color
o Bullae = at the edge, including a small part of the blister with adjacent normal intact skin - keep the blister roof attached. Want to get some normal skin, the border, and the lesion
BIOPSY CONSIDERATIONS
- all biopsies leave scars!
- important cosmetic areas, such as the face and areas with poor healing should be avoided when possible
- when there is a lesion(s) involving cosmetic areas, it may be preferable to refer to a dermatologist or plastic surgeon
where should you NOT use epi?
fingers / toes / nose / ears / penis
derm anesthetics
Lidocaine 1%
Lidocaine 1% with epinephrine (1:100,000)
Lidocaine 2.0% + Prilocaine 2.5% (EMLA cream)
which anesthetic is useful for procedures requiring anesthesia of the fingers, toes, nose, penis, or ear
lidocaine 1%
The standard solution of lidocaine has a pH of
5-7
buffer lidocaine with ________________ which will change the pH to
sodium bicarbonate
7 - 7.2
add 1 part sodium bicarb to 9 or 10 parts lidocaine
purpose of buffering lidocaine
decrease the discomfort associated with injection and to enhance anesthetic tissue dispersion.
Useful for anesthesia in all procedures except those that involve the fingers, toes, nose, penis, or earlobes, or in patients on non-selective beta blockers
lidocaine 1% with epi
lidocaine 1% with epi = Useful for anesthesia in all procedures except those that involve the fingers, toes, nose, penis, or earlobes, or in patients on ____
non-selective beta blockers
propranolol (Inderal), nadolol (Corgard)
advantages of epi to lido
Less bleeding
Prolongs anesthetic action
Also allows for larger volumes of anesthetic to be used safely (maximum 7 mg/kg = 49 cc for 70 kg person) (normally is 4 mg/kg = 28 cc for 70 kg person)
PROCESS FOR ANESTHETIZING AREA
Draw Lido with a 16-18G needle and switch out to a 25-30 G needle to use on the pt
Small syringe: 3-5cc
Make initial injection perpendicular to the skin
Inject directly into or immediately adjacent to small lesions
Must be infiltrated into the dermis to elevate a lesion for biopsy
LOCAL BLOCK / ANESTHESIA
Slowly inject small volumes of anesthetic taking care to monitor the total dose administered.
During anesthetic infiltration, either slowly advance the needle or initially insert it to the hub, and infiltrate as the needle is withdrawn.
Reinsert the needle through the area just anesthetized, redirecting it along the margins of the wound or circumferentially around the abscess and infiltrate additional anesthetic.
Continue infiltration through previously injected skin until the entire region requiring anesthesia is infiltrated.
After a few minutes, lightly test the skin or wound margins for adequate anesthesia using the injection needle or other sharp object (suture needle, Addson forceps).
FIELD BLOCK
In the field block, anesthetic is infiltrated to the subcutaneous area surrounding the operative field.
The needle is inserted at two points, and anesthetic solution is injected along four lines (walls) that surround the area to be anesthetized
LANGER’S LINES
Round wounds tend to be pulled open in the direction of skin tension lines (Langer’s lines)
They parallel the direction of the collagen in the dermis
Surgical incisions placed parallel to tension lines will close more easily and cosmetically then those placed at a right angle
