Use of lipidomics to investigate sebum dysfunction in juvenile acne.

Acne is a multifactorial skin disorder frequently observed during adolescence with different grades of severity. Multiple factors centering on sebum secretion are implicated in acne pathogenesis. Despite the recognized role of sebum, its compositional complexity and limited analytical approaches have hampered investigation of alterations specifically associated with acne. To examine the profiles of lipid distribution in acne sebum, 61 adolescents (29 males and 32 females) were enrolled in this study. Seventeen subjects presented no apparent clinical signs of acne. The 44 affected individuals were clinically classified as mild (13 individuals), moderate (19 individuals), and severe (12 individuals) acne. Sebum was sampled from the forehead with Sebutape(TM) adhesive patches. Profiles of neutral lipids were acquired with rapid-resolution reversed-phase/HPLC-TOF/MS in positive ion mode. Univariate and multivariate statistical analyses led to the identification of lipid species with significantly different levels between healthy and acne sebum. The majority of differentiating lipid species were diacylglycerols (DGs), followed by fatty acyls, sterols, and prenols. Overall, the data indicated an association between the clinical grading of acne and sebaceous lipid fingerprints and highlighted DGs as more abundant in sebum from adolescents affected with acne.

Molecular and immunological characterization of Staphylococcus aureus in pediatric atopic dermatitis: implications for prophylaxis and clinical management.

S. aureus represents a critical cofactor in atopic dermatitis (AD). In this paper, the prevalence of S. aureus infection/colonization was evaluated in 117 children as well as in their cohabitants, in order to assess the value of S. aureus characterization in predicting disease onset and severity and in providing indications for prophylaxis. Results showed that children with AD as well as their cohabitants had a significantly greater incidence of S. aureus infection/colonization as compared to controls. The genetic characterization showed a virtual identity of the bacteria strains collected at different sites of the patients with those found in the cohabitants, suggesting both a direct transmission between the nasal reservoir and the lesions in the same atopic subject and a risk for reinfection within family cohabitants. These data stress the need of preliminary laboratory assessment and posttherapy control in both AD patients and their close contacts for effective S. aureus eradication.

Comprehensive analysis of the major lipid classes in sebum by rapid resolution high-performance liquid chromatography and electrospray mass spectrometry.

Sebum is a complex lipid mixture that is synthesized in sebaceous glands and excreted on the skin surface. The purpose of this study was the comprehensive detection of the intact lipids that compose sebum. These lipids exist as a broad range of chemical structures and concentrations. Sebum was collected with SebuTape(TM) from the foreheads of healthy donors, and then separated by HPLC on a C8 stationary phase with sub 2 µm particle size. This HPLC method provided high resolution and excellent reproducibility of retention times (RT). Compound mining was performed with time of flight (TOF) and triple quadrupole (QqQ) mass spectrometers (MS), which allowed for the classification of lipids according to their elemental composition, degree of unsaturation, and MS/MS fragmentation. The combination of the two MS systems detected 95 and 29 families of triacylglycerols (TAG) and diacylglycerols (DAG), respectively. Assignment was carried out regardless of positional isomerism. Among the wax esters (WE), 28 species were found to contain the 16:1 fatty acyl moiety. This method was suitable for the simultaneous detection of squalene and its oxygenated derivative. A total of 9 cholesterol esters (CE) were identified and more than 48 free fatty acids (FFA) were detected in normal sebum. The relative abundance of each individual lipid within its own chemical class was determined for 12 healthy donors. In summary, this method provided the first characterization of the features and distribution of intact components of the sebum lipidome.

Milia en plaque: three new pediatric cases.

Milia en plaque (MEP) is an unusual and extremely rare clinical variant of milia, characterized by multiple milia-like lesions overlying an erythematous edematous plaque with histologic findings consistent with milia. MEP tends to affect the middle-aged patients and shows a predilection for women. Among children, this entity is rarely described and, to our knowledge, only four cases have been reported to date in the dermatologic literature. We add three new cases of children, one of whom had an unusual site of presentation.

Relevance of thyroiditis and of other autoimmune diseases in children with vitiligo.

BACKGROUND: Studies that clearly define the possible association of childhood vitiligo with autoimmune and/or endocrine diseases are lacking. OBJECTIVE: To examine the presence of autoimmune disorders, in particular of thyroid disease, in paediatric patients with vitiligo and investigate the utility of such screening in these patients. METHODS: One hundred and twenty-one paediatric patients (40 males, 81 females) with vitiligo were grouped in segmental and non-segmental vitiligo. All patients were screened for thyroid disease. RESULTS: 13 out of 121 patients had different degrees of thyroid parameter alterations. These patients were all affected by the non-segmental type while none of those with the segmental form presented thyroid alterations. CONCLUSION: In paediatric patients with non-segmental vitiligo, a significant incidence of thyroid dysfunction was found. Since vitiligo usually appears before the development of the thyroid disease, it may be useful to screen thyroid autoantibodies in all paediatric patients with non-segmental vitiligo who present symptoms related to thyroid disease.