Photodynamic Therapy Incubation Times for Actinic Keratosis

Inclusion criteria

• Subjects who have been diagnosed with actinic keratosis.
• Subjects who by the investigator deem to be suitable for photodynamic therapy of the face or scalp.
• Males or females ≥ 18 years old
• Fitzpatrick skin types I-VI
• Subjects are in good health as judged by the investigator.
• Subjects who are willing and have the ability to understand and provide informed consent for participation in the study and are able to communicate with the investigator.

Exclusion criteria

• Subjects who by the investigator are not suitable for photodynamic therapy.
• Lesions suspicious or proven for skin cancer
• History of 2 or more ALA- PDT treatments within the past 6 months.
• Use of keratolytics within 2 days of initiation of treatment (e.g., >5% urea, glycolic acid, lactic acid, salicyclic acid)
• Cryotherapy within the past 2 weeks.
• Topical retinoids within the past 4 weeks
• Procedures, such as microdermabrasion, ablative lasers, ALA-PDT, chemical peels, 5-fluorouraci, diclofenac, imiquimod within the past 8 weeks
• Systemic retinoids within the past 6 months
• Pregnant or breast feeding
• Uncooperative subjects or subjects with neurological disorders who are incapable of following directions or who are predictably unwilling to return for follow-up examinations.
• Subjects who are unable to understand the protocol or give informed consent.
• Subjects who in the opinion of the investigator are not suitable for the study.