The goal of this clinical trial is to evaluate the efficacy and safety of a topical cream containing Immortelle (Helichrysum italicum) extract in promoting skin barrier recovery and reducing signs of irritant contact dermatitis in healthy adult participants.

The main questions it aims to answer are:

• Does topical application of Helichrysum italicum extract improve skin barrier recovery following experimentally induced irritant contact dermatitis?
• Does the cream containing Helichrysum italicum extract reduce transepidermal water loss and erythema, and improve skin hydration compared to a standard moisturizing cream?
• Is the topical application of Helichrysum italicum extract safe and well tolerated?

Researchers will compare skin sites treated with a cream containing Helichrysum italicum extract, placebo-treated skin sites, and untreated skin sites to determine whether the addition of the extract provides additional benefits in skin barrier recovery.

Participants will:

• Undergo induction of irritant contact dermatitis using sodium lauryl sulfate (SLS) under occlusion.
• Apply a cream containing Helichrysum italicum extract to one designated skin site and a placebo cream to another designated skin site twice daily throughout the study period.
• Have an additional SLS-treated skin site left untreated to assess natural skin barrier recovery.
• Apply the cream containing Helichrysum italicum extract to a separate area of healthy, intact skin.
• Attend daily study visits for non-invasive assessments of skin barrier function, including transepidermal water loss, skin hydration, and erythema measurements.

Inclusion Criteria:

• healthy volunteers who gave written informed consent

Exclusion Criteria:

• skin disease
• skin damage on measurement sites
• use of corticosteroids, antihistamines and immunomodulators a month prior the inclusion and during the trial
• pregnancy or breastfeeding
• immunosuppression
• allergic or irritant reactions to the constituents of the cream