الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Acne vulgaris is a multifactorial disorder of the pilosebaceous unit. The clinical picture can vary significantly, from mild comedonal acne to fulminant systemic disease. Although all age groups may be affected by its many variants, the peak incidence is during adolescence. Acne has an undeniable psychosocial impact, and affected individuals have an increased likelihood of self-consciousness, social isolation, anxiety disorders, depression and even suicidal ideation.
Clinical presentation includes non-inflammatory and/or inflammatory lesions extending over the face and/or trunk.
Psychological stress is an important factor of acne pathogenesis. Stress related production of hormones, cytokines and neuropeptides may result in the chronic course and exacerbations of the disease.
The pilosebaceous unit works as an endocrinally independent organ and is the control center for a complex neuropeptide regulatory program which functions under control of hypothalamic-pituitary-adrenal (HPA) axis.
The cells within sebaceous glands express functional receptors for neuropeptides such as corticotropin releasing hormone (CRH), melanocortins, and SP.
The neuropeptides affect the activity of the pilosebaceous unit by stimulating proliferation and differentiation of sebaceous glands, lipid synthesis and induction of neutral endopeptidase expression in sebaceous cells.
Substance P, which can be elicited by stress, may promote the development of cytoplasmic organelles in sebaceous cells, stimulate sebaceous germinative cells and induce significant increases in the area of sebaceous glands. It also increases the size of individual sebaceous cells and the number of sebum vacuoles for each differentiated sebaceous cell, all of which suggests that SP promotes both the proliferation and the differentiation of sebaceous gland cell.