Seborrheic dermatitis (SD) is a chronic, relapsing mild skin disorder presenting as sharply defined erythematous patches and plaques with greasy scales, with a predilection in areas with increased density of sebaceous glands, namely the scalp, face, upper trunk, and flexures.1,2 It affects approximately 3% to 5% of the population,3,4 with an even higher density among patients with AIDS, Parkinsonâ€™s disease, or several other medical conditions.3
The prevalence is higher among subjects older than 40 years.4 Infantile seborrheic dermatitis has a higher prevalence (up to 70% of newborns during the first 3 months of life),5 but there is still debate as to whether it represents a distinct dermatitis.1
The pathogenesis of the disease is still not fully understood. The yeast Malassezia species has long been pointed out, but its role remains unclear. However, the number of yeasts logically decreases with antifungal treatment, resulting in clinical improvement and increases in periods of exacerbation.6 Malassezia metabolism was shown to alter sebum composition and promotes inflammation in susceptible individuals.7 Induction of inflammatory cytokine production by keratinocytes was also suggested.8
The standard course of treatment remains the topical antifungals, especially 2% ketoconazole (KCZ) and 1% ciclopirox olamine (CIC). In case of severe SD, low- or medium-potency topical corticosteroids such as 1% hydrocortisone or 0.05% betamethasone dipropionate are also helpful.
Quassia amara features a shrub or small tree originating in South America and containing high levels of active phytochemicals, including the triterpenoid quassinoids. Various biological activities are described in the literature, including antimicrobial and antifungal activities,9 especially on Malassezia yeast (L. Fraenza MD, unpublished data, 2010) and strong anti-inflammatory properties.10,11
Because of the previously disclosed properties, we have successfully administered a topical hydroglycolic extract of Quassia (QX) to patients with SD, and their satisfaction and these unexpected results prompted our decision to conduct a randomized, double-blind comparative study with this topical preparation vs 2% KCZ and 1% CIC.
MATERIALS AND METHODS
Study DesignThis is a randomized, double-blind study comparing the efficacy of a test gel containing 4% QX vs 2% KCZ gel and 1% CIC gel.
The study comprised 60 patients who were randomly assigned to receive either a topical 4% QX gel (n=20), a 2% KCZ gel (n=20), or a 1% CIC gel (n=20). The determination of sample size was established with Lenthâ€™s calculator