Diagnostic · Core
Shave biopsy
Why: obtain a tangential specimen when the clinical question and lesion characteristics make that depth appropriate.
Watch: site choice, depth concept, hemostasis, labeling, and destination.
Open biopsy comparison →Procedures · Rotation-ready observation
See the sequence. Understand the decisions.
Recognize common dermatologic procedures, explain why they are chosen, and know what to watch, ask, and communicate in supervised clinic.
Your role: recognize, understand, observe, identify, and discuss. Reading this page does not establish procedural competency or replace hands-on training and supervision.
PurposeBuild procedural literacy.
LevelStudent → rotator → refresher.
PrerequisiteDerm Foundations recommended.
Time5, 20, or 40 minutes.
Choose your depth
Enter at the level your clinic day allows.
Each route uses the same framework, so a quick orientation still connects to deeper learning.
Quick · 5 minutesRecognize the room
Identify common procedures, equipment, and the clinical question each helps answer.
Core · 20 minutesReason through sequenceConnect selection, preparation, tissue depth, specimen handling, hemostasis, and aftercare.
Deep Dive · 40 minutesCompare and applyWork through plan-changing context, complications, communication, and retrieval practice.
The DermPrep procedure framework
Seven questions keep observation clinically useful.
- What is it?Name the procedure and its broad purpose.
- Why is it done?Define the diagnostic or therapeutic goal before choosing a technique.
- What should I recognize?Identify equipment, anatomy, specimen needs, and safety checks.
- How does it work?Describe the conceptual sequence without treating reading as hands-on training.
- What should I watch?Notice lesion selection, anesthesia, depth, hemostasis, labeling, dressing, and counseling.
- What can go wrong?Recognize complications and know when to involve the supervising clinician.
- What happens next?Understand specimen destination, wound care, results, and follow-up.
Procedure discovery
Start with the question—not the instrument.
A focused launch library. Advanced or incomplete procedures stay out until the evidence and teaching assets are ready.
11 procedure concepts
Diagnostic · Core
Punch biopsy
Why: obtain a cylindrical sample that includes deeper skin levels than a superficial shave.
Watch: lesion selection, orientation, depth, closure decision, and labeling.
Open biopsy comparison →Diagnostic / therapeutic · Concept
Excision concepts
Why: remove a lesion with a planned specimen and closure strategy when clinically appropriate.
Watch: anatomy, margins as a clinical concept, orientation, tension, and follow-up.
Compare tissue goals →Destructive · Core
Cryotherapy
Why: create controlled cold injury for selected lesions.
Watch: diagnosis, site, treatment field, expected reaction, pigment risk, and counseling.
View snapshot →Destructive · Rotation
ED&C concepts
Why: combine curettage with electrosurgical tissue destruction for selected lesions.
Watch: lesion selection, anatomic context, tactile feedback, hemostasis, and wound plan.
View snapshot →Support skill · Core
Local anesthesia
Why: reduce procedural pain while the supervising clinician accounts for agent, site, history, and safety.
Watch: identity checks, planned field, comfort, and monitoring.
Know what to notice →Support skill · Core
Basic suturing concepts
Why: approximate wound edges and manage tension using a closure plan suited to the wound.
Watch: edge alignment, tension, layer, material, dressing, and removal plan.
Compare closure roles →Aftercare · Core
Wound care
Why: protect healing tissue and give clear, procedure-specific follow-up instructions.
Watch: dressing choice, written instructions, bleeding guidance, and reassessment signs.
Review aftercare →Therapeutic · Concept
Intralesional injection
Why: deliver medication into a selected lesion or tissue plane.
Watch: diagnosis, site, medication verification, distribution concept, and counseling.
View snapshot →Sampling · Core
KOH preparation
Why: examine an appropriately collected sample for fungal elements.
Watch: active sampling site, specimen amount, slide handling, and interpretation limits.
Open sampling concepts →Sampling / nail · Concept
Scraping, culture & nail sampling
Why: collect the material most likely to answer the diagnostic question.
Watch: correct site, container, label, destination, and local laboratory requirements.
Open sampling concepts →No complete launch concept matches that search. Try a broader procedure, goal, instrument, or specimen term.
Featured pathway
Biopsy choice begins with the diagnostic question.
Technique, lesion, body site, required tissue, suspected diagnosis, and pathology needs must align.
Conceptual illustration only; not a scale drawing or operative guide.
Shave
Tangential tissue goal
Useful when the required diagnostic tissue can be obtained with a tangential approach. “Shave” does not mean one fixed depth.
Common mistake: choosing it only because a lesion looks raised.
Punch
Cylindrical tissue goal
May support questions that benefit from architecture through deeper cutaneous levels. Diameter and site are only part of the decision.
Common mistake: assuming a punch is always the best “full-thickness” answer.
Excision
Planned removal and closure
Integrates diagnostic or therapeutic intent with anatomy, specimen orientation, margin concepts, and closure planning.
Common mistake: equating diagnostic biopsy language with definitive oncologic excision.
Say it like this
State the question before the instrument.
Less useful: “I would punch this.”
Better: “The biopsy should sample the tissue needed to answer the diagnostic question. I would first clarify the suspected process, representative site, required depth, anatomic constraints, and pathology handling with the supervising clinician.”
What changes the plan?
A “biopsy” request is not enough information.
Initial scenario: a persistent papule needs tissue diagnosis.
New information: the lesion is pigmented, the suspected diagnosis depends on architecture and depth, and the pathology team may need specific orientation. The tissue goal and handling plan now deserve explicit discussion before selecting a technique.
Biopsy choice follows the clinical question, representative site, depth, anatomy, and specimen requirements.
Explain what tissue is needed and which contextual factor makes one approach more informative.
Observe selection, labeling, destination, hemostasis, dressing, and counseling; clarify uncertainty with the supervisor.
Watch for this in clinic
Turn observation into deliberate practice.
Use the checklist to guide attention—not to perform independently.
Before
- What is the diagnostic or therapeutic goal?
- Why this lesion and this site?
- What history or anatomy changes the plan?
- What specimen or equipment is expected?
During
- How are comfort and safety addressed?
- What depth, field, or tissue response matters?
- How is hemostasis approached conceptually?
- What does the operator communicate aloud?
After
- How is the specimen identified and routed?
- Why was this closure or dressing chosen?
- What reactions are expected?
- Which symptoms prompt reassessment?
When to pause and involve your supervising clinician
Unclear consent or site, unexpected allergy or medication history, uncertain diagnosis or specimen requirements, concern about bleeding or infection, unexpected pain or tissue response, mislabeled or unlabelled tissue, or any change beyond your assigned role.
Procedure snapshots
Recognize the purpose, then watch the decision points.
These are conceptual orientations, not universal protocols.
Cryotherapy
What it is: controlled cold injury used for selected lesions.
Why this procedure: the diagnosis, site, lesion characteristics, treatment goal, expected response, and risk profile make a destructive approach reasonable.
Watch: diagnostic confidence, treatment field, tissue response, site-specific risk, expected blistering or discomfort, pigmentary change, and counseling.
Do not assume: one freeze time or cycle applies to every lesion.
Electrodesiccation and curettage
What it is: curettage paired with electrosurgical destruction for selected lesions.
Why this procedure: lesion type, borders, depth, body site, recurrence risk, cosmetic context, and operator judgment support it.
Watch: selection, anesthesia, tactile feedback, cycle concept, hemostasis, wound plan, and follow-up.
Do not assume: ED&C is interchangeable with excision or appropriate for every tumor.
Intralesional injection
What it is: local delivery of medication into selected tissue.
Why this procedure: a local therapeutic goal may allow focused treatment.
Watch: medication and site verification, distribution concept, patient comfort, expected local effects, and follow-up.
Do not assume: reading about a concentration, volume, or technique authorizes its use.
Deep Dive: equipment recognition and the conceptual sequence
Preparation → anesthesia → procedure → hemostasis → specimen or wound → aftercare
Biopsy tools obtain tissue; the tool must match the tissue question. Local anesthetic supplies support comfort and procedure planning. Hemostatic materials may support pressure, chemical, or electrosurgical approaches depending on context. Sutures approximate tissue and manage tension in a planned layer. Specimen containers are selected for the intended test—not every sample goes into the same medium. Curettes mechanically scrape selected tissue. Cryotherapy equipment delivers controlled cold injury.
Ask three questions when you see an instrument: What is it? Why is it being used here? What decision or safety check should I notice?
Specimens and bedside sampling
The specimen is part of the procedure.
Label and destination
Connect the correct patient, site, specimen, container, and intended study. Use local laboratory and pathology requirements; do not assume all tissue belongs in routine formalin.
KOH and scraping
Sample the material most likely to contain the target. For suspected superficial fungal disease, the active area and adequate scale or nail material matter; interpretation must fit the clinical context.
Culture or special studies
When infection, immunofluorescence, culture, or another special study is considered, clarify handling before collection because the required container and transport may differ.
Communication
Give pathology or the laboratory the clinical question, site, and relevant differential. Institution-specific workflows should remain local—not universal claims.
Aftercare and complications
Know what is expected—and what deserves reassessment.
Instructions vary by procedure, wound, site, patient, and clinician. Follow the treating team’s plan.
Expected course
Mild discomfort, local swelling, drainage, blistering, crusting, bruising, or pigment change may be expected after some procedures—but the expected pattern depends on the procedure.
General wound concepts
Clear cleansing and dressing instructions, a protected healing environment, bleeding guidance, and a results or follow-up plan reduce confusion. Avoid individualized advice outside the treating team.
Red flags to recognize
Bleeding that does not respond to the team’s instructions, rapidly increasing pain or swelling, spreading redness, purulent drainage, fever, wound separation, neurovascular symptoms, or an unexpected reaction should prompt clinical reassessment.
Results loop
Confirm how results will be communicated, what follow-up is planned, and what happens if pathology and the clinical impression do not align.
Commonly confused
Compare the decision—not just the words.
Select a comparison lens.
| Question | Shave concept | Punch concept |
|---|
Common mistakes
Correct the reasoning before memorizing technique.
Choosing the procedure first
Define the diagnostic or therapeutic question before selecting an instrument.
Ignoring depth and anatomy
Ask what tissue is needed and what the site changes.
Treating all biopsies as interchangeable
Match lesion, question, architecture, depth, specimen, and closure considerations.
Forgetting destination requirements
Clarify labeling, container, special study, and local workflow before collection.
Skipping aftercare
The procedure is incomplete without wound guidance, expected reactions, red flags, results, and follow-up.
Confusing knowledge with competency
Conceptual fluency supports supervised learning; it does not establish independent skill.
If your attending asks
Lead with the clinical question.
Why this procedure?
Connect morphology and suspected diagnosis to the need for tissue or treatment, required depth, body site, and the procedure’s limitations.
What would change your plan?
Consider location, suspected diagnosis, required specimen, allergy history, medications affecting bleeding, infection concern, healing risk, and local pathology requirements—then discuss them with the supervisor.
What are you watching during the procedure?
Lesion and site confirmation, comfort, tissue goal, hemostasis, specimen handling, closure or dressing, counseling, and follow-up.
What could go wrong?
Name relevant complications without claiming a universal rate: bleeding, infection, pain, scarring, pigment change, wound problems, diagnostic sampling error, or procedure-specific injury.
Retrieval practice
Try one question.
30-second recap
- Start with the diagnostic or therapeutic goal.
- Recognize equipment by purpose, not appearance alone.
- Observe anatomy, comfort, tissue response, hemostasis, and communication.
- Plan specimen handling and aftercare before the procedure ends.
- Conceptual understanding is not independent competency.
One thing to remember: the safest learner asks what question the procedure is meant to answer.
Next best actions
Keep the learning loop moving
Also connects to Treatments, Visual Diagnosis, Rotation Ready, and the canonical Glossary.
Sources & page information
- American Family Physician. Shave and punch biopsy for skin lesions.
- DermNet. Skin biopsy.
- DermNet. Cryotherapy.
- DermNet. Curettage and cautery.
- DermNet. Skin surgery.