The aim of the study is to evaluate the effect of oral isotretinoin on SerumYKL40 in acne vulgaris patients.

Acne vulgaris is a common chronic inflammatory disease of the skin. It is found in about 80% of young adults and adolescents. It is a disease that affects the pilosebaceous units of the skin and may result in inflammatory or non-inflammatory lesions,Oral isotretinoin (13-cis-retinoic acid) is the only drug that counteracts all the pathogenetic mechanisms that contribute to the development of acne .The standard dose of isotretinoin is 0.5 to 1 mg/kg per day for 4 months to a cumulative dose of 120-140 mg/kg is effective in the management of acne vulgaris The scope of our study is to detect serum YKL-40 level in acne patient before and after oral isotretinoin treatment

Inclusion Criteria:

1. Healthy persons of both sexes with moderate and severe acne.
2. Age above 14 years.

Exclusion Criteria:

1. Pregnant and lactating women, immunocompromised patients.
2. History of chronic liver disease, hyperlipidemia, non-inflammatory acne conditions, , history of neurologic disorders, history of neoplastic disorders, and history of cardiac disease.
3. History of systemic acne treatment for at least 4 weeks prior to inclusion and no topical treatments for at least 2 weeks.
4. Cases with known hypersensitivity reaction to isotretinoin.