Dermatology

Question 1

Fungal Infections of the Skin and Nails

Answer 1

• Intertrigo
  
  • Cutaneous infection MC in moist, macerated areas
  • Pruritus rash beefy red erythema w/ distinct, scalloped borders & satellite lesions
  • Management = topical Clotrimazole
• Onychomycosis
  
  • Nail infection by various fungi (ex tinea, candida)
  • MC on great toe
  • Opaque, thickened, discolored & cracked nails w/ subungual hyperkeratinization
  • Diagnosis
    
    • KOH smear
  • Management
    
    • Itraconazole & Terbinafine
      
      • Associated w/ hepatotoxicity so need to monitor LFTs

Question 2

Herpes Zoster

Answer 2

• VZV reactivation along one dermatome of the dormant virus in the spinal root & cranial nerve ganglia
• Management of shingles = Acyclovir (given within 72 hours to prevent PHN)

Question 3

Contact Dermatitis

Answer 3

• Irritant: chemicals, detergents, cleaners, acids, prolonged water exposure
• Clinical manifestations
  
  • Burning, itching & erythema to the affected area, dry skin, eczematous eruption
• Management
  
  • Avoid irritants

Question 4

Rosacea

Answer 4

• Chronic acneiform disorder mainly affecting females between 30-50yrs
• Dz of pilosebaceous units associated w/ increased activity of capillaries, which leads to flushing and telangiectasias
• Outbreaks are episodic; typically occur in response to heat, alcohol, sun, or hot, spicy foods
• Clinical features
  
  • Insidious onset of scattered, small papulopustules and sometimes nodules; face appear red or flushed
• Treatment
  
  • Reduce triggers such as alcohol or hot beverages
  • Topical metronidazole

Question 5

Cellulitis

Answer 5

• MCC = Staph and GABHS
• Clinical manifestations
  
  • Macular erythema, not sharply demarcated, swelling, warmth, and tenderness
  • Medical management
    
    • Keflex; Dicloxacillin
    • Clindamycin or Eryhtromycin in PCN allergic
    • MRSA = IV vancomycin or Linezolid

Question 6

Actinic Keratosis

Answer 6

• MC seen in fair-skinned elderly with prolonged sun exposure
• Premalignant condition to squamous cell carcinoma
• Clinical manifestations
  
  • Dry, rough, scaly “sandpaper” skin lesion or erythematous, hyperkeratotic (hyperpigmented) plaques
• Diagnosis
  
  • Punch or shave biopsy
• Management
  
  • Observation, surgical (cryosurgery, dermabrasion); medical (5-FU)

Question 7

Sebhorreic Keratosis

Answer 7

• MC benign skin tumor
• MC in fair-skinned elderly w/ prolonged sun exposure
• Clinical manifestations
  
  • Small papule/plaque velvety warty lesion w/ “greasy/stuck on appearance”
• Management
  
  • No treatment needed (benign)
  • Cosmetic - cryotherapy

Question 8

BCC

Answer 8

• MC type of skin cancer in the US
• Slow growing – locally invasive but very low incidence of metastasis
• Clinical manifestations
  
  • Small, raised, translucent/pearly/waxy papule and central ulceration & raised, rolled borders
  • MC on face/nose/trunk; bleeds easily
• Diagnosis
  
  • Punch or shave biopsy
• Management
  
  • Electrodesiccation/curettage used MC in nonfacial tumors
  • +/- Mohs micrographic surgery for facial involvement

Question 9

Malignant Melanoma

Answer 9

• UV radiation associated w/ 80% of cases
• Aggressive; high METS potential
• MC skin cancer-related death
• 4 major subtypes
  
  • Superficial spreading: MC type
  • Nodular
  • Lentigo maligna
  • Acral lentiginous
  • Desmoplastic – most aggressive type
• Clinical manifestations
  
  • ABCDE = Asymmetry, Borders: irregular; Color: variation (dark blue, black); Diameter: usually >6mm, Evolution (suspect in a lesion w/ recent/rapid change in appearance)
  • Thickness = most important prognostic factor for METS
• Diagnosis
  
  • Full-thickness wide excisional biopsy + lymph node biopsy
• Management
  
  • Complete wide surgical excision

Question 10

SCC

Answer 10

• 2^nd MC skin cancer
• Often preceded by actinic keratosis, HPV infection
• Bowen’s diseases = squamous cell carcinoma in situ; slow growing
• Clinical manifestations
  
  • Red, elevated thickened nodule w/ white scaly or crusted, bloody margins
• Diagnosis
  
  • Biopsy
• Management
  
  • Wide local surgical TOC

Question 11

Ulcers

Answer 11

• Stage 1 = superficial, nonblanchable redness that does not dissipate after pressure is relieved
• Stage 2 = Epidermal damage extending into the dermis; resembles a blister or abrasion
• Stage 3 = Full thickness of the skin and may extend into the subcutaneous layer
• Stage 4 = Deepest. Extends beyond the fascia, extending into the muscle, tendon, or bone
• Management
  
  • Wet to dry dressings, hydrogels
  • I, II = local wound care, pain management.
  • III and IV may need surgical debridement

Question 12

Stasis Dermatitis

Answer 12

• Associated w/ chronic insufficiency
• Eczematous rash, itching, scaling, weeping erosions w/ crusting +/- cellulitis
• Management
  
  • Wet to dry dressings, unna boot, edema control
  • If severe à skin grafting