Investigation of the Effect of Lipikar Baume AP+M

Corneometer® (Courage + Khazaka electronics GmbH, Cologne, Germany) is used to assess skin hydration after 28 days. The Corneometer® measures in arbitrary units from 0 (no water) - 120 (on water). The units are referred to as "Corneometer® units". In total there will be 3 measurements at each point (Actinic keratosis, perilesional, never by actinic keratosis affected skin/healthy). The average of the 3 measurements is calculated and day 0 and day 28 are compared.

Transepidermal water loss (in g/m2/h - TEWL) measured by Tewameter® (Courage + Khazaka electronics GmbH, Cologne, Germany). 3 measurements at each arm und lesion will be taken (Actinic keratosis, perilesional and never by actinic keratosis affected skin). The average of the 3 measurements is calculated and day 0 and day 28 are compared.

The AKASI is a standardized tool for the clinically adequate assessment of larger areas (1). The area, distribution, erythema, and thickening of actinic keratoses are evaluated according to Dirschka et al. and a score is calculated. The score is between 0-18. Average values of study participants of each study group will be compared (day 0, day 28).

• Dirschka T, Pellacani G, Micali G, Malvehy J, Stratigos AJ, Casari A, et al. A proposed scoring system for assessing the severity of actinic keratosis on the head: actinic keratosis area and severity index. J Eur Acad Dermatol Venereol. 2017;31(8):1295-302.

S. aureus colonization and S. epidermidis colonization is assessed after 28 days by skin swabs and qPCR. Quantification is based on fluorescence measurements taken in real time during a PCR cycle. Fluorescence increases in proportion to the amount of PCR product. At the end of a run (consisting of several cycles), quantification is performed in the exponential phase of the PCR using the fluorescence signals obtained. Mean Ct values (cycle threshold) of the study groups are given for qPCR.

The investigator will assess the subject's skin aspect on the following signs or symptoms: scarring, atrophy, induration, redness or change in pigmentation.

The Score is between 0 (poor) and 3 (Excellent). The investigator will assess the subjects skin aspect at day 28 for all lesions, that have disappeared. An anverage of the score is calculated for all lesions in each study group.

Actinic keratoses that are clearly visible or palpably are counted at each study site (left and right arm and back of the hands).

Absolute lesion counts by application site will be compared (day 0 and day28).

The percentage of lesions with an improvement of at least one grade (Olsen grade) at day 28 will be assessed.

For this the Olsen classification of each actinic keratosis should be recorded. This classification is based on a three-grade grading of the thickness of a single lesion and was first proposed by Olsen et al. Grade 1 describes a slightly palpable lesion, grade 2 a moderately thick and grade 3 a very thick and hyperkeratotic lesion. If actinic field cancerization is present, the highest Olsen grade in the area will be assessed.

Average Olsen Scores by application site of Day 0 and D28 will be compared.

All new actinic keratoses in the study area are recorded by application site (left and right arm and back of the hands).

Day 0 and Day 28 will be compared concerning the average of new lesions by application site.

A symptom score with a four-point Likert scale (absent, light, moderate, severe) is assessed as patient reported outcome (PRO). The symptom score includes four principal symptoms (itch, unpleasant burning, pain, tingling).

The paper questionnaire with 4 questions will be handed out to the patient at Day 0 and Day 28. The symptom score is assessed for botch arms separately. The average scores by application will be compared concerning the overall score and the individual symptom scores (itch, burning etc.) at day 0 and day 28.

To assess the general satisfaction with Lipikar Baume AP+M an according to the study procedures modified TSQM-9 will be applied. This is a questionnaire that has been evaluated for the evaluation of antihypertensive medications but can also be applied to dermatological diseases.

This includes nine questions with Likert-scaled answers to assess the satisfaction with the cosmetic.

As the TSQM-9 was developped for medical agents, we changed the word medicament to "cosmetic", to assess the score at day 0 and day 28. The average of score of day 0 and day 28 will be compared.

A patient diary is used to assess the days on which Lipikar Baume AP+M was used.

The proportion of patients with at least 75% of days and >90% of days on which Lipikar Baume AP+M was used will be calculated.

Pictures of the forearms and back of the hands are taken to illustrate the effects of Lipikar Baume AP+M.