98 ACTA DERMATOVENEROLOGICA CROATICA Acta Dermatovenerol Croat 2012;20(2):98-104 REVIEW Seborrheic Dermatitis: An Update Zrinka Bukvić Mokos 1 , Martina Kralj 2 , Aleksandra Basta-Juzbašić 1 , Ines Lakoš Jukić 1 1 University Hospital Center Zagreb, Department of Dermatology and Venereology, School of Medicine University of Zagreb; 2 Department of Dermatology, Karlovac General Hospital, Karlovac, Croatia Corresponding author: Assist. Prof. Zrinka Bukvić Mokos, MD, PhD University Hospital Center Zagreb Department of Dermatology and Venereology School of Medicine University of Zagreb Šalata 4 HR-10000 Zagreb Croatia zrinka.bukvic@zg.t-com.hr Received: October 25, 2011 Accepted: May 15, 2012 SUMMARY Seborrheic dermatitis is a chronic relapsing inlammatory skin disorder clinically characterized by scaling and poorly deined erythematous patches. The prevalence of adult seborrheic dermatitis is estimated at 5%. Although the exact cause of seborrheic dermatitis has yet to be understood, Malassezia yeasts, hormones (androgens), sebum levels and immune response are known to play important roles in its development. Additional factors including drugs, winter tem- peratures and stress may exacerbate seborrheic dermatitis. A variety of treatment modalities are available, including antifungal agents, topical low-potency steroids and calcineurin inhibitors (immunomodulators). This review summarizes current knowledge on the etiopathogenesis and therapy of adult seborrheic dermatitis. KEY WORDS: seborrheic dermatitis, Malassezia yeast, sebum, antifun- gal agents INTRODUCTION Seborrheic dermatitis (SD) is a common chronic relapsing inlammatory skin disorder clinically char- acterized by poorly deined erythematous patches and scaling. SD primarily afects sebum rich areas, in- cluding scalp, face, upper chest and back (1). The prevalence of adult SD is estimated at 5% (2). This condition is more common in males than in females. Among adults, the peak incidence is in the third and fourth decades of life. Although the exact cause of SD has yet to be understood, Malassezia yeasts, hormones (androgens), sebum levels and im- mune response are known to play important roles in its etiopathogenesis (3). Some researchers propose a pivotal role for Malassezia yeasts (formerly called Pity- rosporum ovale) in seborrheic dermatitis (4). Antifun- gal therapy leads to decreased colonization with Mal- assezia spp. and concomitant disappearance of skin lesions, which is probably the strongest evidence that Malassezia spp. have momentous role in the develop- ment of SD (5). Other therapeutic options include corticosteroids, immunomodulators and antibiotics. ETIOLOGY AND PATHOGENESIS Despite quite a high prevalence of this disorder, the exact cause is poorly understood. However, sev- eral factors (Malassezia yeasts, hormones, sebum lev- els, immune response, neurogenic factors, external factors) seem to be involved in SD etiopathogenesis, but the exact pathogenetic mechanism still remains controversial.