INTRODUCTION
skin disorder
SKIN DISORDER, DISEASE, SEBORRHEIC DERMATITIS, PATHOPHYSIOLOGY, SEBORRHEIC DERMATITIS
Seborrheic dermatitis is a common skin disorder related to the growth of fungus in the skin, which affects about 4% of the world's population. This disease is more common in men than women, which can happen both in infancy and at any age after puberty.Seborrheic dermatitis is a clinical diagnosis based on the location and appearance of the lesions,However, in relation to botulinum toxin, it should be known that the injection of this compound for the treatment of facial wrinkles, is the most common cosmetic procedure performed in the United States.Regarding the effect of botulinum toxin injection on the symptoms of seborrheic dermatitis, there are two conflicting theories in the articles. In the first theory, the proven effect of botulinum toxin in the dermis layer on reducing the amount of production and secretion of skin sebum, regulating the secretion of skin neurotransmitters and blood flow under the skin through mediators.Therefore, considering the proven therapeutic effects of botulinum toxin and the pathophysiology of seborrheic dermatitis, the contradictory hypotheses raised regarding the effect of injection of this toxin on the improvement or exacerbation of seborrheic dermatitis lesions and the lack of coherent studies in the field of exploring this relationship, we decided to conducting this study, for evaluate the effect of local botulinum toxin injection on sebum production and improvement or exacerbation of seborrheic dermatitis lesions.