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Skin Integrity & Wounds
- Conditions involving disruption of the skin barrier, where the exam focus is severity assessment, infection risk, and appropriate management, not dermatologic pattern recognition.
Burns
- Thermal, chemical, electrical, or radiation injury to the skin, classified by depth and total body surface area (TBSA), which together determine urgency and management
Clinical Presentation
- First degree: erythema, pain, no blistering
- Second degree: blistering, moist appearance, very painful
- Third degree: white or charred skin, painless, full-thickness injury
- Severity increases with larger TBSA, deeper burns, and critical locations
- The question stem will sound like: a patient with blistering burns after a kitchen accident and the question is what to do next
Assessment
- Burn depth
- Total body surface area (TBSA) = percentage of body involved in partial- and full-thickness burns
- High-risk locations: face, hands, feet, genitals, major joints, circumferential burns
- Assess for inhalation injury if facial burns, hoarseness, soot, or respiratory symptoms are present
Estimating TBSA
- Rule of Nines (adults)
- Head and neck: 9 percent
- Each arm: 9 percent
- Each leg: 18 percent
- Anterior trunk: 18 percent
- Posterior trunk: 18 percent
- Perineum: 1 percent
- Palm method
- Patient’s palm including fingers equals about 1 percent TBSA
- Useful for small or irregular burns
- Children require age-adjusted charts (Lund-Browder)
Management
- Immediate cooling with cool running water
- Chemical burns → brush off dry agents, then copious irrigation
- Pain control
- Tetanus update
- Topical antibiotics for partial-thickness burns
- IV fluids for large burns (classically >20 percent TBSA in adults)
- Burn center referral for deep burns, large TBSA involvement, inhalation injury, or critical locations
Exam Keys
- Blisters = at least second-degree
- Painless burn = full thickness
- Large TBSA or critical areas = escalate care
Lacerations
- Disruption of the skin caused by trauma, where the exam focus is wound assessment, infection risk, and appropriate closure
Clinical Presentation
- Linear or irregular break in the skin
- May involve subcutaneous tissue, muscle, tendon, or nerve depending on depth
- Bleeding may be present
- Mechanism matters: clean vs contaminated, sharp vs crush injury
- The question stem will sound like: a patient with a cut from a kitchen knife or glass and the question is whether and how to close it
Assessment
- Depth of wound
- Neurovascular status distal to the injury
- Tendon involvement, especially hands and fingers
- Contamination or foreign bodies
- Time since injury
- Clean wounds: primary closure usually within 12 hours
- Face and scalp: primary closure up to 24 hours
- Contaminated wounds: higher infection risk, consider delayed closure
Management
- Copious irrigation is the most important step
- Tetanus update
- Primary closure for clean wounds within the appropriate time window
- Delayed closure or healing by secondary intention for contaminated or late-presenting wounds
- Antibiotics only if high-risk (contaminated wounds, bites, immunocompromised)
Special Considerations
- Bite wounds (especially human and cat) → high infection risk, often not closed primarily
- Hand and joint wounds → higher risk, lower threshold for referral
- Deep wounds with tendon or nerve injury → surgical evaluation
Exam Keys
- Time matters for closure
- Face buys you more time
- Irrigation before closure
Pressure Injury
- Localized injury to skin and underlying tissue caused by prolonged pressure or pressure with shear, most often over bony prominences, where the exam focus is staging and prevention
Clinical Presentation
- Common locations: sacrum, heels, hips, elbows
- Risk increased with immobility, malnutrition, incontinence, and advanced age
- May range from intact skin with erythema to deep tissue loss
- The question stem will sound like: a hospitalized or nursing home patient with limited mobility who develops a wound over the sacrum or heel
Staging
- Stage 1: intact skin with nonblanchable erythema
- Stage 2: partial-thickness skin loss, blister or shallow open ulcer
- Stage 3: full-thickness skin loss, subcutaneous fat visible
- Stage 4: full-thickness tissue loss with exposed muscle, tendon, or bone
- Unstageable: base covered by slough or eschar
- Deep tissue injury: persistent purple or maroon discoloration with intact skin
- Stages do not progress linearly and do not reverse during healing
Management
- Pressure offloading is the most important intervention
- Frequent repositioning
- Optimize nutrition and hydration
- Moist wound care
- Debridement if necrotic tissue is present
- Treat infection only if clinical signs of infection
Prevention
- Regular skin assessments
- Pressure-relieving surfaces
- Early mobilization when possible
Exam Keys
- Nonblanchable erythema = Stage 1
- Bone or muscle exposed = Stage 4
- Offload pressure first
Hypersensitivity & Reactive Derm
- Acute skin reactions driven by histamine release and immune activation, where the exam focus is severity assessment and management, not lesion description
Urticaria
- Transient, pruritic wheals caused by histamine mediated vascular permeability, often triggered by allergens, medications, infections, or physical stimuli
Clinical Presentation
- Raised, erythematous wheals with central pallor
- Intensely pruritic
- Lesions are transient, typically resolving within 24 hours
- May migrate and change shape
- The question stem will sound like: a patient with sudden onset itchy welts that appear and disappear over hours and the question is how severe this is
Assessment
- Look for systemic symptoms suggesting anaphylaxis
- Dyspnea, wheezing
- Hypotension
- Lip, tongue, or throat swelling
- Determine acute vs chronic
- Acute: less than 6 weeks
- Chronic: more than 6 weeks
Management
- First-line: oral H1 antihistamines
- Short course corticosteroids for severe or refractory symptoms
- Epinephrine if signs of anaphylaxis
- Avoid known triggers when identified
Exam Keys
- Urticaria that comes and goes within 24 hours = benign
- Airway or hypotension = epinephrine
- Severity drives management, not appearance
Urticaria
Transient, pruritic wheals caused by histamine-mediated vascular permeability, often triggered by allergens, medications, infections, or physical stimuli
Clinical Presentation
- Raised, erythematous wheals with central pallor
- Intensely pruritic
- Lesions are transient, typically resolving within 24 hours
- May migrate and change shape
- May occur with angioedema
- The question stem will sound like: a patient with sudden onset itchy welts that appear and disappear over hours and the question is how severe this is
Assessment
- Look for systemic symptoms suggesting anaphylaxis
- Dyspnea, wheezing
- Hypotension
- Lip, tongue, or throat swelling
- Determine acute vs chronic
- Acute: less than 6 weeks
- Chronic: more than 6 weeks
Management
- First-line: oral second-generation H1 antihistamines
- Short course corticosteroids for severe or refractory symptoms
- Epinephrine if signs of anaphylaxis
- Avoid known triggers when identified
Exam Keys
- Urticaria that comes and goes within 24 hours = benign
- Airway involvement or hypotension = epinephrine
- Severity drives management, not appearance
Pilonidal Disease
- Chronic inflammatory condition of the sacrococcygeal region caused by ingrown hairs, leading to cysts, sinus tracts, or abscess formation
Clinical Presentation
- Painful swelling or drainage near the natal cleft
- May present as an acute abscess or chronic draining sinus
- Often affects young adults, especially males
- Risk factors include prolonged sitting, obesity, and coarse body hair
- The question stem will sound like: a young adult with pain and drainage just above the gluteal cleft and the question is what to do next
Assessment
- Look for fluctuance suggesting abscess
- Assess for recurrent disease or chronic sinus tracts
- No routine imaging needed
Management
- Acute abscess → incision and drainage
- Chronic or recurrent disease → surgical excision
- Hair removal and hygiene to reduce recurrence
- Antibiotics only if cellulitis or systemic signs are present
Exam Keys
- Painful mass near the natal cleft = pilonidal disease
- Abscess = I&D
- Recurrent disease = surgery
Skin Neoplasms
- Abnormal growths of skin cells ranging from benign to malignant, where the exam focus is recognition, cancer risk, and next step management, not detailed histology
Benign Skin Neoplasms
- Benign skin lesions may look alarming but have no malignant potential, and the exam focus is reassurance vs removal, not cancer risk
Seborrheic Keratosis (Benign) – covered in episode 155
- Benign, noncancerous epidermal growth with no malignant potential
- Waxy, stuck-on appearance in older adults
- Included here to contrast with premalignant and malignant lesions
- Reassurance only, no treatment unless symptomatic or cosmetic
Premalignant Skin Lesions
- Lesions that are not cancer, but represent UV-induced cellular damage with potential to progress to malignancy, requiring treatment and surveillance, not reassurance
Actinic Keratosis (Premalignant) Covered in 155
- Premalignant keratinocyte lesion from chronic UV exposure
- Rough, scaly, sandpaper-like lesion on sun-exposed skin
- Serves as a risk marker for squamous cell carcinoma
- Management focuses on treatment and surveillance, not reassurance
Malignant Skin Neoplasms
- True skin cancers with destructive or metastatic potential, where the exam focus is recognition, biopsy, and definitive treatment, not reassurance or watchful waiting
Basal Cell Carcinoma
- Most common skin cancer, arising from basal cells, caused by chronic UV exposure, with low metastatic risk but significant local tissue destruction if untreated
Clinical Presentation
- Pearly or translucent papule with rolled borders
- May show telangiectasias
- Can bleed easily or form a nonhealing ulcer over time
- Common on sun-exposed areas, especially face, nose, ears, and neck
- Slow growing
- The question stem will sound like: an older patient with a small shiny bump on the nose that bleeds occasionally and never fully heals
Assessment
- Suspicious appearance on sun-exposed skin
- Biopsy is required to confirm diagnosis
- No routine metastatic workup needed due to low spread risk
Management
- Surgical excision is first-line
- Mohs surgery for lesions on the face, ears, nose, or recurrent tumors
- Radiation therapy if not a surgical candidate
Prognosis
- Excellent with treatment
- Rarely metastasizes, but can cause extensive local destruction if ignored
Exam Keys
- Pearly papule + rolled borders + bleeding = basal cell carcinoma
- Low metastatic risk, high local damage
- Biopsy then excision
Squamous Cell Carcinoma
- Malignant tumor of keratinocytes arising from chronic UV exposure, often evolving from actinic keratosis, with real metastatic potential
Clinical Presentation
- Firm, erythematous papule, plaque, or nodule
- Often scaly or crusted
- May ulcerate or bleed
- Common on sun-exposed areas such as face, ears, scalp, and dorsal hands
- Grows faster than basal cell carcinoma
- The question stem will sound like: an older patient with a rough, enlarging lesion on the ear or hand that bleeds and has been growing over months
Risk Factors
- Chronic sun exposure
- History of actinic keratosis
- Immunosuppression
- Chronic wounds or scars
Assessment
- Biopsy required to confirm diagnosis
- Evaluate for high-risk features (size, depth, location, immunosuppression)
Management
- Surgical excision is first-line
- Mohs surgery for high-risk locations or recurrent lesions
- Radiation therapy if not a surgical candidate
Prognosis
- Higher metastatic risk than basal cell carcinoma
- Prognosis depends on early detection and treatment
Exam Keys
- Scaly, firm lesion on sun-exposed skin = think SCC
- AK → SCC progression
- Biopsy then excision
- More aggressive than basal cell carcinoma
Melanoma
- Malignant tumor of melanocytes with high metastatic potential, where early recognition and excision are life-saving
Clinical Presentation
- Pigmented lesion with asymmetry, border irregularity, color variation, diameter >6 mm, or evolution
- May be flat or raised
- Can arise from a pre-existing nevus (mole) or appear as a brand-new pigmented lesion
- Found anywhere on the body, commonly on the back in men and legs in women
- The question stem will sound like: a patient with a changing mole that has become darker, irregular, or larger over time
Assessment
-
ABCDE Criteria • – A – Asymmetry (halves don’t match) • – B – Border irregularity (notched, uneven edges) • – C – Color variation (multiple shades: brown, black, red, white, blue) • – D – Diameter >6 mm • – E – Evolution (any change in size, shape, color, or symptoms — most important)
-
Excisional biopsy required for diagnosis
-
Shave biopsy is not appropriate when melanoma is suspected
Management
- Wide local excision is definitive treatment
- Further management guided by tumor depth, which is the most important prognostic factor (Breslow thickness)
- Oncology referral for advanced disease
Prognosis
- Strongly dependent on depth at diagnosis
- Early melanoma has excellent prognosis
- Delayed diagnosis significantly increases mortality
Exam Keys
- Changing pigmented lesion = melanoma until proven otherwise
- ABCDE criteria
- Excisional biopsy
- Depth matters most
Skin Neoplasms – Key Differentiators
- Actinic keratosis vs squamous cell carcinoma → flat, rough, sandpaper-like lesion vs firm, scaly or ulcerated lesion that enlarges or bleeds
- Basal cell carcinoma vs squamous cell carcinoma → pearly papule with rolled borders vs firm, erythematous, scaly or crusted lesion
- Basal cell carcinoma vs melanoma → shiny, non-pigmented pearly lesion vs pigmented lesion with asymmetry and color variation
- Seborrheic keratosis vs melanoma → waxy, stuck-on plaque vs changing or irregular pigmented lesion
- Actinic keratosis vs melanoma → rough scaly sun-damage marker vs pigmented lesion with ABCDE changes
