Download procedures in dermatology-

Procedures in Dermatology
Overview
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Shave biopsy
Punch biopsy
Incision & Drainage (I&D)
Excisions
Electrodessication & Curettage (ED&C)
• Cryotherapy
What is a skin biopsy?
• A skin biopsy is a diagnostic procedure in which a
portion of skin (and/or subcutis) is submitted to
the pathology lab.
• This specimen is fixed, sectioned and placed on
slides for histologic analysis
• Special stains can be used to detect fungus,
bacteria, immune complexes, lymphocytes,
inflammatory mediators, arthropods.
• The hope is that the pathologist can provide more
information to aid in diagnosing the disease.
Skin Biopsy
• A good skin biopsy is one that provides an
adequate specimen for the pathologist to review
while at the same time using the utmost care and
knowledge of anatomy to minimize the potential
morbidity of the procedure.
• Also involves post-biopsy wound care, knowledge
of anatomical danger zones, patient education.
Why do a skin biopsy?
• Skin biopsies usually provide diagnostic
information that adds to the clinical picture
already at hand.
• Many skin diseases have characteristic findings on
routine histology that are highly diagnostic
• Biopsy results that don’t make sense at all should
be viewed with doubt – (the lab makes mistakes
too!)
• You might have to biopsy a lesion several times
prior to definitive diagnosis.
Why do a skin biopsy?
• Ascertain benign vs. malignant, infectious
vs. autoimmune, exogenous vs. endogenous
process.
• If strongly suspect skin cancer, biopsy can
generate information such as subtype,
differentiation, depth of invasion, type of
spread, which guides appropriate choices
for treatment
Keep in mind, skin biopsy not
necessary if….
• The clinical picture is entirely diagnostic.
• If patient history and PE findings strongly
point to a specific diagnosis, and you feel
comfortable in diagnosing on clinical
grounds alone, don’t do a skin biopsy.
• If the disease doesn’t respond to treatment
or doesn’t follow the expected clinical
course, then biopsy may be necessary.
1- Biopsy by shave technique
• Removal of representative piece of skin by
tangential incision with a blade.
• Can use scalpel or Dermablade
• Idea is to sample both lesional and normalappearing perilesional skin
• Depth needs to get down to at least superficial
upper dermis – biopsies of epidermis only usually
unsatisfactory.
• Some skin diseases require sampling of mid to
deep dermis for diagnosis.
Dermablade
Shave biopsy using dermablade
When to do a shave
• In sensitive anatomic locations where the
depth of a punch biopsy puts nerves/blood
vessels at risk (anatomic danger zones.)
• The highly active patient: Shave biopsy
wounds have no limitation on activity.
• The patient who can’t/doesn’t want to come
back for suture removal from punch biopsy.
How to do a shave
• Inform patient of potential for scarring!
• Anesthetize the area for biopsy, starting with the
subcutis and working you way up to the
dermoepidermal junction (bleb or peau d’orange.)
• Map in your mind or with a surgical pen the
specimen you are trying to collect beforehand (as
with many things in life/work, it helps to have a
plan first!)
• Create skin tension with hands or an assistant’s
hands.
How to do a shave
• Look at Video .
Shave biopsy – Wound Care
• Resulting defect is usually a circular to ovular
extending down into papillary to mid-reticular
dermis.
• Hemostasis with aluminum chloride for minimal
bleeding/Electrocautery for moderate bleeding.
• After hemostasis achieved, ointment and occlusive
dressing are applied.
• Important that patient educated on keeping would
moist and occluded until healed.
2-Biopsy by punch technique
• Removal of a representative piece of skin
and subcutis with a punch
• Best way to look at it is like a little
cylindrical cookie-cutter which punches all
the way through the skin
• Usually a more involved procedure than
shave needing extra time for anesthesia,
hemostasis and would closure
When to do a punch
• Punch superior for any skin diseases where a
picture of the deep dermis/subcutis is diagnostic.
• Tends to provide more information for
inflammatory skin disorders, as they tend to
involve greater depth of dermis
• Usually a better choice for the scar-averse patient,
although it is no guarantee as even the best punch
biopsy closure can dehisce.
• Better choice for deeply-seated lesions in dermis
and subcutis.
How to do a punch
• Look at video
How to do a punch
• Hemostasis then obtained with combination of
manual pressure, electrocautery or aluminum
chloride solution.
• Never forget: Pressure is the King of
Hemostasis!
• Wound then closed with sutures, or can be left to
heal by second intention (warn patient extended
wound care for 1-4 weeks in these cases)
3- Excision and excional biopsy
• Procedure whereby a full thickness specimen of
skin is removed either for therapeutic or
diagnostic purposes.
• Excisions usually in elliptical shape oriented
along skin tension lines (Langer’s lines.)
• Suture the wound
• Procedure learned by seeing/doing.
• See the video
Why do an excision?
• Usually done to completely remove a lesion
for therapeutic reasons:
1. Can also be used for excisional biopsy
2. Skin cancer
3. Dysplastic nevus (abnormal mole)
4. Epidermal inclusion cyst
4- Electrodessication and
Curettage (ED&C)
• Essentially a process whereby superficial
cancerous and pre-cancerous growths are
removed from the skin by repeated scraping
and burning.
• An effective, safe, expedient means of
treating certain skin cancers in certain
locations.
Hyfrecator
ED&C indications
• Indicated for SCC in situ, superficial and
selected nodular BCC.
• Works best on trunk and extremities in nonhairbearing areas
• Extreme caution on scalp, neck and highrisk areas of the face.
Cryotherapy
Cryotherapy:
the destruction of skin lesions
using a cold substance
most commonly liquid
nitrogen LN2
destruction is selective,
affecting tissue only
Cryotherapy - Indications
Treatment of:
Benign lesions
Premalignant lesions
Malignant lesions
Table 1.
Some of the common conditions
responsive to cryosurgery.
Benign lesions
8 Viral Warts
8 Skin tags
8 Seborrhoeic keratoses
8 Sebaceous hyperplasia
8 Molluscum contagiosum
8 Milia
Pre-malignant lesions
8 Actinic/solar keratoses
8 Bowens disease (Intra-epithelial carcinoma)
8 Actinic cheilitis
Malignant Lesions
8 Superficial basal cell carcinomas
Cryotherapy - Equipment
The equipment required depends on the method
and technique used
Methods:
 Open spray
- 40 ̊C
Cotton bud
- 20 ̊C
Metal forceps
- 15 ̊C