Creams used by hand eczema patients are often contaminated with Staphylococcus aureus.

Skin lesions, such as atopic dermatitis and eczema, are often colonized with high densities of microorganisms, especially Staphylococcus aureus (1–3). Severity and persistence of both atopic and hand eczema has been associated with S. aureus colonization (2, 4). Besides colonizing eczema S. aureus is also one of the most frequently found contaminants in cosmetic products (5–7), and cosmetics contaminated with S. aureus have previously been identified as the cause of dermal infection (8). Studies on contamination of different types of cosmetics during use have shown that Staphylococcus spp. in particular S. epidermidis, are found in the products (5, 9–12). In addition, yeast and mould, such as Candida spp. and Aspergillus spp., are also frequently found in used cosmetics (9, 11, 13). This study investigated hand creams used by patients with hand eczema for microbial contamination, focussing especially on S. aureus. Hand creams used by 20 patients with hand eczema were collected while the patients underwent routine patch testing at the Dermato-Allergology Department at Gentofte Hospital. In order to quantify the number of microorganisms present in each product parts of the protocol 2.6.12 from the European Pharmacopoeia 6.5 " Microbiological examination of non-sterile products: microbial enumeration tests " were followed (14). Briefly, 1 g cream was dissolved in 9 ml buffered NaCl-peptone solution (pH 7.0) and serial diluted to 10 –3 g/ml. From each dilution 0.1 ml was dispersed on two 5% sheep blood agar plates (OXIOD) and incubated at 37ºC for 5 days. The number of new colonies was recorded on each of the 5 days. The total number of colony forming units (CFU) was counted and the CFU/g cream was calculated based on the mean number of CFU on two plates from the same dilution if the number of CFU was between 10 and 200 on each plate. Characterization of the colonies was performed by selecting morphologically different colonies and several similar colonies from the blood plates. Each isolated colony was transferred to a new blood plate in order to ensure pure colonies. All isolates underwent microscopy, and bacterial isolates were Gram-stained. To identify S. aureus all Gram-positive cocci were tested for coagulase (Staphaurex ® REMEL). It was also tested whether the contact areas of the cream were contaminated. With an inoculation loop a small quantity of cream was removed from the opening of tubes or the edge of jars and suspended in 1 ml NaCl-peptone solution. 0.5 and …