Efficacy and Safety of Low-dose Oral Isotretinoin for Seborrhea

Oral isotretinoin is a retinoid that controls gene expression related to cellular proliferation, differentiation, with specific action over sebocytes, reducting sebaceous gland size and secretion rate. Its binding to specific retinoid nuclear receptors is weak. It is the gold standard drug to treat moderate to severe acne. Other indications have been suggested: seborrhea, seborrheic dermatitis, rosacea and non-melanoma skin cancer prevention. There are well known reversible side effects like the mucocutaneous - cheilitis, dryness of skin, nose and eyes and risk of alterations in lipid profile and transaminases. The major problem is teratogenicity which demands pregnancy control by two different methods, from treatment beginning to one month after treatment end.

Seborrhea and seborrheic dermatitis are chronic and correlated conditions characterized by oily skin, hair and scalp, erythema, desquamation and negative impact on quality of life. Seborrhea is a very common problem, affecting 30% of population. Seborrheic dermatitis affects 3 to 5% of world population, with no differences for gender and race. The etiopathogenic factors involved in these conditions are: individual susceptibility, elevated sebaceous secretion and irritant action of products from lipophilic yeasts of Malassezia gender. The treatment usually involves topical use of corticosteroids, salicylic acid, ketoconazole, ciclopirox olamine, pimecrolimus and tacrolimus. The dermatosis impact on quality of life has been more and more evaluated by generic and specific questionnaires. The most used generic questionnaires are:"Dermatology Life Quality Index or DLQI" and "Medical Outcomes Study 36-Item Short-Form Health Survey or SF-36". Recently a specific questionnaire for oily skin named "Oily Skin Self-Image Questionnaire or OSSIQ" was published. This will be an interventional, therapeutic and quality of life randomized, comparative (parallel groups), blinded evaluation clinical trial, comprising 50 men and women, aged 18 to 40. Treatment with low-dose oral isotretinoin (20 mg a day, every other day) will be compared to topical anti-seborrheic products to evaluate the reduction of sebaceous secretion and colonization of affected areas by saprophyte yeasts of Malassezia gender. Efficacy will be evaluated by clinical parameters, as well as by sebum measure and application of two quality of life questionnaires: SF-36 and OSSIQ (after translation and validation for Brazilian Portuguese). Safety will be evaluated by skin hydration measure, side effects report and observation. The devices Sebumeter and Corneometer, from Courage \& Khazaka, Köln, Germain, will be used. For subjects using oral isotretinoin blood counting, transaminases, lipid profile and pregnancy test will be requested as selection criteria, on days 30 and 180. Results will be submitted to statistical analysis.