Behind the Knife ABSITE 2026: Skin & Soft Tissue Infections and Cancers

Surgical Care Improvement Project Initiatives

• 🎯 Seven initiatives from the Surgical Care Improvement Project aim to reduce surgical site infections.
• 💡 Key initiatives include avoiding hypoglycemia, maintaining normothermia, administering prophylactic antibiotics within 60 minutes of incision, selecting appropriate antibiotics, discontinuing prophylaxis within 24 hours, using clippers for hair removal, and removing urinary catheters within two postoperative days.

Necrotizing Soft Tissue Infections (NSTI)

• ⚠️ A diabetic patient with severe pain, erythema, and crepitus on their thigh after a scratch is a concern for necrotizing soft tissue infection (NSTI).
• 🔬 NSTIs are classified as necrotizing cellulitis (skin/subcutaneous), necrotizing myositis (muscle), or necrotizing fasciitis (muscle/fascia).
• 📊 The L-R-I-N-E-C score (WBC > 15k, CRP > 150, Hgb < 13.5, Na < 135, Glucose > 180) can increase suspicion for NSTI if ≥ 6.
• ⚡ Treatment involves early surgical debridement, broad-spectrum antibiotics (e.g., vancomycin, clindamycin, zosyn/unasyn), and potential return to the OR within 24 hours.
• 🔍 Imaging findings like gas in soft tissue on CT are highly specific for NSTI.

Hand and Extremity Infections

• 📌 An acute paronychia (infection of the nail fold) is treated with incision and drainage, lifting the nail bed, and antibiotics.
• 🛠️ Chronic paronychia may benefit from topical steroids and avoiding water immersion; nail plate removal is a last resort.
• 🩹 A felon is an infection of the fingertip pulp, treated with a vertical incision to avoid damaging neurovascular structures.

Hidradenitis Suppurativa (HS) and Pilonidal Disease

• 🦠 Hidradenitis Suppurativa (HS) involves chronic, recurring infections of apocrine sweat glands, common in axillae, inframammary folds, and groins. Risk factors include smoking, obesity, and being female.
• 📈 HS severity is staged using the Hurley system: Stage 1 (abscesses), Stage 2 (sinus tracts, scarring), Stage 3 (diffuse disease). Treatments range from lifestyle modifications and antibiotics to TNF-alpha inhibitors and wide surgical excision with skin grafting.
• 🚀 Pilonidal disease affects the gluteal cleft, often in younger adults with higher BMI and thick hair. Management includes lifestyle changes, hair removal, and for acute infections, incision and drainage. Surgical options include cleft lift or excision.

Skin Cancers

• 🌟 Basal cell carcinoma is the most common skin cancer, presenting as raised, waxy lesions with rolled edges. Treatment is wide local excision with 4-10 mm margins.
• ⚠️ Squamous cell carcinoma, preceded by actinic keratosis, appears as ulcerated skin with raised, irregular borders. Treatment is also wide local excision with 4-10 mm margins.
• 🚨 Merkel cell carcinoma is rare, rapidly growing, firm, red/purple nodules. Staging involves PET scan. Treatment includes wide resection (1-2 cm margins), sentinel lymph node biopsy, and adjuvant radiation for stage II/III disease.
• melanoma is diagnosed using the ABCDE criteria (Asymmetry, Border irregularity, Color variation, Diameter > 6mm, Evolution). Diagnosis is via full-thickness biopsy. Excisional margins depend on Breslow depth (0.5-2 cm).
• 🔬 Sentinel lymph node biopsy is indicated for melanomas with Breslow depth ≥ 0.8 mm or high-risk features like ulceration.
• 🩺 For metastatic melanoma, treatment options include PD-1 inhibitors (e.g., pembrolizumab) and CTLA-4 antibodies.
• 🦶 Subungual melanoma requires digit amputation, with sentinel lymph node biopsy if Breslow depth is > 1 mm.

Lymph Node Dissections and Quick Hits

• 📍 Superficial inguinal lymphadenectomy targets nodes within the femoral triangle.
• 🫀 Deep inguinal lymphadenectomy encompasses nodes from the common iliac artery bifurcation down to the pelvic sidewall.
• 💧 Herpetic whitlow is managed with observation and avoiding contact; incision and drainage can cause systemic spread.
• 📈 Striae atrophicae (stretch marks) may be treated with excision for reconstruction.
• 🦠 The most common cause of lymphangitis is Streptococcus pyogenes (Group A Strep).
• 🤢 Fournier's gangrene is a necrotizing infection of the perineum, commonly caused by E. coli, Klebsiella, and Enterococcus.