Inclusion Criteria:  Over 18 years. Patients treated with any systemic therapy (other than topical therapy) according to criteria clinical and routine clinical practice. Therefore, the treatments included will be: phototherapy, cyclosporine, methotrexate, azathioprine, mycophenolate, dupilumab, baricitinib, upadacitinib and tralokilumab. Patients who grant informed consent.  Exclusion Criteria:  Patients who do not have the necessary comprehension capacity to understand and sign the informed consent. Patients who, according to routine clinical practice, require only topical treatment.