Sensitive skin is defined as a syndrome manifested by the occurrence of unpleasant sensations (tingling, burning, pain, pins and needles) in response to stimuli that should not normally cause them. These unpleasant sensations cannot be explained by lesions attributable to a specific skin disease. Sensitive skin can affect different parts of the body. The scalp is a site that is often affected, with specificity linked in particular to the presence of hair and different triggering factors (styling habits, wearing of head coverings, application of cosmetics to the scalp, etc.). Sensitive scalp affects around half the population, and can have an impact on the quality of life of sufferers, particularly those whose symptoms are very intense. Women are more likely than men to have a sensitive scalp, so in order to have a more homogenous study population, we chose to include 40 women. The pathophysiology of sensitive skin is imperfectly understood, and studies specific to the sensitive scalp are very rare. However, the pathophysiology of the sensitive scalp could be different because it is a hairy area, more innervated, and less exposed to environmental factors.

Each patiente will have a sample taken in the dermatology department:

• 1 skin biopsy of the scalp (non-routine medical procedure)

• Completion of questionnaires

• Collection of skin microbiota (optional)

  40 adult women

• 20 women with a sensitive scalp (cases)

• 20 women without a sensitive scalp (controls)

Patientes with the sensitive scalp will be recruited from the dermatology department. There will be no further visits, so the duration of the study is 1 day.

Inclusion Criteria:

• Adult women without dermatosis
• Collection of free and informed consent
• patient affiliated to a social security scheme

For the control group: Sensiscalp score = 0/20 Sensitive scalp group: Sensiscalp score ≥ 3/20 with pruritus sensation ≥ 2/20

Exclusion Criteria:

• Refusal to take part in the study
• Dermatosis of the scalp (psoriasis, seborrhoeic dermatitis, etc.)
• Pregnant and breast-feeding women
• Women under legal protection (guardianship, curatorship)

Women are more likely than men to have a sensitive scalp, so in order to have a more homogenous study population, we chose to include 40 women.

All collected data that underlie results in a publication

Data will be available beginning three years and ending fifteen years following the final study report completion

Data access requests will be reviewed by the internal committee of Brest UH. Requestors will be required to sign and complete a data access agreement.

Histological and innervation analyses will be carried out in a blinded fashion.