Dermatology Book

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Actinic KeratosesAka: Actinic Keratosis

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  1. See Also
    1. Nonmelanoma Skin Cancer
    2. Squamous Cell Carcinoma
  2. Epidemiology
    1. Most common premalignant skin lesion
      1. Responsible for 60% of Squamous Cell Carcinoma involving the skin
    2. Prevalence: White skin (increases with age)
      1. Age 20-29: 10%
      2. Age 80-89: 75%
  3. Pathophysiology
    1. Superficial keratotic tumor
    2. Previously considered distinct premalignant changes
    3. Now thought to be very early Squamous Cell Carcinomas
      1. Ortonne (2002) Br J Dermatol 146:20
  4. Risk Factors
    1. Fair-skinned, blue-eyed persons
    2. Living in sunny climate
    3. Cummulative extensive Sun Exposure
    4. Older persons
  5. Symptoms
    1. Typically asymptomatic
    2. May be pruritic or burning
  6. Signs
    1. Characteristics: Rough Scaly patches
      1. Discrete, circumscribed
      2. Verrucous or keratotic
      3. White scale or rough patch
      4. Red-brown, pink or skin-colored Macule or Papule
      5. Often recurs after patient "picks off" scale
      6. Vary in size from millimeters to centimeters
    2. Distribution: Sun exposed areas
      1. Face and neck
        1. Left more common (Car driver's window side)
      2. Dorsal hands
      3. Forearms
  7. Diagnosis
    1. Diagnosis by "feel": Rough
    2. Biopsy is rarely indicated
  8. Management: Procedures
    1. Cryotherapy with Liquid Nitrogen
      1. Debride hyperkeratotic lesions first
      2. Freeze, slowly thaw and then refreeze
      3. Efficacy increases with duration of freeze time
        1. Freeze 5 seconds: 39% cure rate
        2. Freeze 20 seconds: 83% cure rate
    2. Curettage
      1. Infiltrate area with local anesthetic
      2. Consider for hyperkeratotic lesions
      3. Adjuncts
        1. Trichloroacetic acid (TCA) before curettage
        2. Electrosurgery post-curettage to destroy residual tissue
    3. Photodynamic therapy
      1. Photosensitizer applied to skin followed by exposure to specific light source
      2. Protocols
        1. Aminolevulinic Acid (Levulan Kerastick): Exposure to blue light after 14 hours
        2. Methyl aminolevulinate (Metvixia): Exposure to red light after 3 hours
  9. Management: Topical Treatments
    1. Indicated when >15 lesions present
    2. Topical 5-Flourouracil
      1. Preparations
        1. Fluorouracil cream 5% (Efudex)
        2. Fluorouracil cream 1% (Fluoroplex)
        3. Fluorouracil microspore cream 0.5% (Carac)
      2. Adverse effects
        1. Dryness, erythema, irritation and even disfigurement on the face
        2. More common with 5% cream; 0.5% appears better tolerated
      3. Technique
        1. Use bid for 2-4 weeks until marked inflammation
        2. Consider 0.5% cream for one week prior to Cryotherapy
    3. Topical Diclofenac 3% gel in 2.5% hyaluronic acid (Solaraze)
      1. Technique: Apply twice daily for 90 days
      2. Efficacy: Complete resolution in 50% of cases
      3. Adverse Effects: Local irritation, dryness and Pruritus
      4. Reference
        1. Rivers (1997) Arch Dermatol 133:1239
    4. Imiquimod 5% Cream (Aldara)
      1. Applied 3-4 times weekly at bedtime and wash off in AM; use for up to 16 weeks
      2. Efficacy
        1. Complete response in up to 57% of patients
        2. Partial response (75% reduction) in up to 72% of patients
      3. Adverse effects
        1. Cosmetic outcomes not studied
        2. Severe erythema (80%)
        3. Severe Erosions (40%)
      4. References
        1. Stockfleth (2002) Arch Dermatol 138:1498
    5. Chemical peels for face (applied by dermatology)
      1. Similar efficacy to fluorouracil
      2. Preparations
        1. Jessner's Solution (Resorcinol, Lactic Acid, Salicylic acid)
        2. Trichloroacetic acid 35% (Tri-Chlor)
      3. References
        1. Lawrence (1995) Arch Dermatol 131:176
  10. Prevention
    1. See Sun Exposure (lists general preventive measures)
    2. See Sunscreen
  11. Course
    1. Spontaneous resolution in 25% of lesions
    2. Progression to squamous cell cancer: 6-10% over 10 years
  12. References
    1. Habif (2004) Dermatology p. 736-43
    2. Mcintyre (2007) Am Fam Physician 76(5):667
    3. Stulberg (2004) Am Fam Physician 70:1481

Actinic keratosis (C0022602)

Definition (NCI)(ak-TIN-ik ker-a-TOE-sis) A precancerous condition of thick, scaly patches of skin.
Definition (NCI)A precancerous lesion of the skin composed of atypical keratinocytes. It is characterized by the presence of thick, scaly patches of skin. Several histologic variants have been described, including atrophic, acantholytic, and hyperkeratotic variants.
ConceptsNeoplastic Process (T191)
ICD9702.0
EnglishACTINIC KERATOSIS, AK - Actinic keratosis, Atrophic keratosis, Hyperplastic keratosis, Keratinocytic intraepidermal neoplasia, Senile hyperkeratosis, Senile keratoma, Senile keratosis, SENILE SOLAR KERATOSIS, SK - Solar keratosis, Solar keratosis
Spanishhiperqueratosis senil, neoplasia intraepidermica queratinocitica, queratoma senil, queratosis actinica, queratosis hiperplasica, queratosis senil, queratosis solar
Parent ConceptsOther dermatoses NOS (C0029574), Pre-Malignant Skin Epithelial Lesion (C1335463), Precancerous Conditions (C0032927), Solar elastosis (C0263415), Benign epithelial neoplasm of skin (C0345981), Hyperkeratosis (C0870082), Benign epithelial neoplasm - category (C1302886), Duplicate concept (C1274013)
SourcesCOSTAR, DXP, ICD9CM, MTH, NCI, PDQ, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



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