A Multi-center Study to Evaluate the Efficacy and Safety of PEP005 (Ingenol Mebutate) Gel, When Used to Treat Actinic Keratoses on the Head (Face or Scalp)

Inclusion Criteria: * Patient is male or female and at least 18 years of age * Female patients must be of either: * Non-childbearing potential, post-menopausal * Childbearing potential, provided there are negative serum and urine pregnancy test results prior to study treatment, to rule out pregnancy Exclusion Criteria: * Cosmetic or therapeutic procedures within 2 weeks and 2cm of the selected treatment area * Treatment with immunomodulators, or interferon/ interferon inducers or systemic medications that suppress the immune system within 4 weeks * Treatment with 5-FU, imiquimod, diclofenac, or photodynamic therapy: within 8 weeks and 2 cm of the selected treatment area