Koebner's Phenomenon in Psoriasis and Lichen Planus

Who can take part

• Dermatologist diagnosed psoriasis (group psoriasis), lichen planus (group lichen planus) or no skin disease (group healthy controls)
• Subject is capable of giving informed consent
• Signed informed consent

Who cannot take part

• Known or suspected non-compliance, drug or alcohol abuse,
• Previous enrolment into the current study,
• Active or recurrent serious bacterial, fungal or viral infection at the time of enrollment by patient history, including patients with Human Immunodeficiency Virus (HIV) infection, Hepatitis B and Hepatitis C infection, active or untreated latent tuberculosis
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant,
• Use of systemic immunosuppressive/immunmodulating agents in the last three months
• Use of topical anti-inflammatory treatment in the last 7 days in the area of sampling
• Phototherapy in the last 4 weeks
• Female patients of childbearing potential who are pregnant or breast feeding or planning a pregnancy during the duration of the trial and/or not practicing acceptable birth control for the duration of the trial
• Enrolment of the investigator, his/her family members, employees and other dependent persons