BackgroundPeople who are genetically predisposed to atopic dermatitis as well as those who are exposed to external triggers are more likely to acquire the condition. An epidermal barrier deficiency and immunological dysregulation are regarded to be the root causes of Alzheimer's disease (AD). When inflammation occurs, the liver produces CRP, a pentameric protein that rises in concentration. There are 112 amino acids in Irisin, which is a protein. Skeletal muscle, heart muscle, liver, pancreas, salivary gland, connective tissue, sweat glands, subcutaneous adipose tissue, and the nerve sheath all produce this substance when they are used for muscular contraction and movement. New myokine might reduce obesity and enhance glucose utilisation. Some of the positive benefits of exercise, such as weight reduction and thermoregulation, may be mediated by this substance in humans. Irisin serum levels in patients with moderate and severe atopic dermatitis were assessed in this research, with the goal of determining whether there was a correlation between CRP levels and disease activity and inflammation. Methods: Thirty people with Alzheimer's disease participated in this research. 20 healthy people of the same age and sex were also included in the study as an additional control group. In addition to a thorough clinical and dermatological assessment, each participant in the study received a full medical history. All patients were picked from Benha University Hospitals' Dermatology Outpatient Clinic. Slight, moderate, and severe cases were classified based on their SCORAD scores. Research involving human subjects at Benha Faculty of Medicine was given the go light by the institution's local ethics committee. Before any samples were collected at the Clinical and Chemical Pathology Department Faculty of Medicine Benha University, informed permission was acquired from each participant. It was shown that Irisin and CRP had a negative relationship, as Irisin had a substantial negative correlation with SCORAD whereas CRP had a significant positive connection with SCORAD, according to the findings of this research There is some evidence to support the idea that CRP may be used to assess the severity of AD, and that Irisin may be able to lessen the disease's effects. CRP and Irisin may be used as indicators of the severity of Alzheimer's disease (AD). Also, obesity, which lowers Irisin levels, may put people at risk for Alzheimer's disease.