Actinic Keratosis

1. Actinic Keratosis Rob Sheehan-Dare Leeds Centre for Dermatology

2. Pre-Cancerous Lesions • Actinic Keratoses • Intra-epithelial Squamous Cell Carcinoma • Lentigo maligna • Skin Cancer • Basal Cell Carcinoma • Squamous Cell Carcinoma • Melanoma • Lymphoma

3. What are Actinic keratoses? • Epidermal dysplasia • Associated with UV exposure • Sun exposed sites • Elderly • Outdoor occupations • Warmer climates • Lighter skin types • Immunosuppression

4. What are Actinic keratoses? • Histologically • Epidermal cell disorganisation • Acanthosis • Reduced granular layer • Parakeratosis • Hyperkeratosis

6. What is risk of malignancy? • ?Less than 1:1000 per year • Increased by • Immunosuppression • Increased numbers of lesions • Co-factors (radiation, exposure to tar) • Prior Squamous cell carcinoma • Some lesions resolve spontaneously • Most SCC’s are well differentiated

7. What do they look like? • Clinically • Adherent scale (variable but always) • Erythema (often) • Light pigmentation (sometimes) • Merge with surrounding skin • Usually not indurated

11. Diagnostic difficulties • Cutaneous horn • Hypertrophic actinic keratoses • Inflammatory lesions • Often in immunosuppressed

12. What to treat • Lesions in immunosuppressed patients • Lesions at high risk sites (e.g. lip) • Where previous history of SCC • Inflamed Actinic keratoses • Lesions in younger age group • Symptomatic lesions

13. How to treat • Cryotherapy • Curettage & cautery • 5-fluorouracil cream • Diclofenac gel • Imiquimod cream • Photodynamic therapy

14. Cryotherapy • Destruction by cold injury • Cotton bud or cryospray • 20-30 second freeze • Moderate pain • Immediate blistering • Heals in 10 days • Suitable for small/few lesions • Suitable where compliance poor

17. Curettage and cautery • Physical removal/thermal injury • Requires local anaesthesia • Moderate pain • Eschar • Heals in 10 days • Suitable for solitary/few lesions • Suitable for cryo resistant lesions • Suitable for hyperkeratotic lesions • Suitable where histology required

18. 5-fluorouracil cream • Inhibits DNA synthesis by inactivating thymidine synthase • 4 weeks treatment • Inflammatory reaction (moderate-severe) • Little pain • Interrupted treatment may be required • Suitable for multiple/extensive lesions • Suitable for compliant patients

19. Diclofenac gel • Inhibits Cyclo-oxygenase (COX-2) • 8 weeks treatment • Mild-moderate inflammatory reaction • No pain • Long term benefits uncertain • Suitable where intolerance to other treatment

20. Imiquimod cream • Toll-like receptor 7 agonist induces apoptosis • 4-8 weeks treatment • Inflammatory reaction (moderate-severe) • Little pain • Interrupted treatment may be required • Suitable for multiple/extensive lesions • Suitable for compliant patients

21. Photodynamic therapy • ALA induced protoporphyrin IX synthesis sensitizes cells to photodynamic effect • 1-2 prolonged treatments • Moderate pain • Inflammatory reaction (moderate-severe) • Heals in 10 days • Suitable for multiple/extensive lesions • Suitable where compliance poor

22. Treatment summary • Cryotherapy small/few lesions • 5-fluorouracil larger/multiple lesions • Curettage for hyperkeratotic lesions • Solaraze for patients with poor tolerance • Imiquimod cream or PDT for resistant lesions

23. “They look benign , but keep out of the sun”