Photodynamic therapy technique (PDT) is a conventional technique which is performed applying the product under occlusion lesions, let it incubate for 3 hours and then exposed skin to a light source, usually red.

The conclusions of efficacy, tolerance and satisfaction that today are known about PDT with MAL, but not with ALA, which is a new photosensitizer indicated for Actinic Keratoses. The pharmaceutical form of ALA is a gel, which gives a hypothetical better penetration and consequently it is more effectively.

Intraindividual comparative study, to evaluate efficacy and safety of the treatment of actinic keratosis with photodynamic therapy between methyl aminolevulinate cream (MAL) and aminolevulinic acid nanosoma gel (ALA).

MAL cream: is an antineoplastic agent used as a photosensitizer for photodynamic therapy (PDT). The mode of action of methyl aminolevulinate in PDT was shown in the pharmacodynamic (PD) studies. In the target cells,methyl aminolevulinate was converted to photoactive porphyrins, including protoporphyrinIX (PpIX), which are the active photosensitizers. Upon light activation, the photosensitizers give rise to the production of cytotoxic singlet oxygen species which destroy the target cells.

ALA gel: Following topical application of 5-aminolaevulinic acid, the substance is metabolized to protoporphyrin IX, a photoactive compound which accumulates intracellularly in the treated actinic keratosis lesions. Protoporphyrin IX is activated by illumination with red light of a suitable wavelength and energy. In the presence of oxygen, reactive oxygen species are formed. The latter causes damage of cellular components and eventually destroys the target cells.

Photodynamic therapy technique (PDT) is a conventional technique which is performed applying the product under occlusion lesions, let it incubate for 3 hours and then exposed skin to a light source, usually red.

The conclusions of efficacy, tolerance and satisfaction that today are known about PDT with MAL, but not with ALA, which is a new photosensitizer indicated for QA. The pharmaceutical form of ALA is a gel, which gives a hypothetical better penetration and consequently it is more effectively.

Inclusion Criteria:

1 Patient over 18 years old and capable of giving informed consent.

2. Provide at least 5 QA in two symmetrical areas of the face or scalp.

3. Accept the abandonment of sun creams and other creams (retinoic hydroxy acids, emollients, Topical Antibiotics ) in the treatment area during the time of the study.

4. Accept that it will postpone the treatment of other actinic keratosis close to treatment area.

5. Accept to go to scheduled visits. They should answer a questionnaire about epidemiology, history and treatment satisfaction. They will accept a photo of treatment area at each visit.

Exclusion Criteria:

1. Have any dermatological disease on the treatment zone or around it.

2. Patients who have previously been treated with therapy Photodynamic in targeted areas.

3. Patients with alcohol or drug dependence.

4. Patients who are currently participating in other studies.

5. Patients who have received any of the following medications at a time less than the indicated:

   • Systemic chemotherapy in the last 6 months.
   • Retinoids systemic , interferon , immunomodulatory or immunosuppressive , cytotoxic including agents , corticosteroids systemic , in the last month .
   • Ultraviolet A light, Ultraviolet B light, ablative laser, dermabrasion, chemical peels, in the last 6 months.
   • Topical retinoids , topical 5 -fluorouracil in the last month.
   • Cryotherapy , surgical excision, curettage, topical corticosteroids in the last month.