Methicillin-resistant Staphylococcus aureus colonization in inflammatory versus non-inflammatory skin diseases: who should be screened?

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) was prospectively investigated in a dermatology outpatient setting. Swabs were taken from anterior nares, perineum and lesional skin in 229 patients with erosive inflammatory skin diseases (n=88), venous leg ulcers (n=58) or basal cell carcinoma (n=83) and processed by standard methods. The isolated MRSA strains were characterized by pulsed-field gel electrophoresis after digestion with the restriction enzyme SmaI. MRSA carriage was detected in 10/88 patients with inflammatory skin diseases, 5/58 with venous leg ulcers and 0/83 with basal cell carcinoma. Most of the MRSA isolates could be identified as either the Rhine-Hessen epidemic strain or local epidemic strains. None of the isolated strains was resistant to vancomycin, gentamicin or mupirocin. MRSA is uncommon in outpatients in our dermatology clinic; however, the presence of chronic ulcers and erosions was significantly associated with MRSA positivity. Therefore, patients with chronic ulcers and erosions should be screened for MRSA colonization to implement infection control measures.     

Staphylococcus aureus hijacks a skin commensal to intensify its virulence: immunization targeting β-hemolysin and CAMP factor

The need for a new anti-Staphylococcus aureus therapy that can effectively cripple bacterial infection, neutralize secretory virulence factors, and lower the risk of creating bacterial resistance is undisputed. Here, we propose what is, to our knowledge, a previously unreported infectious mechanism by which S. aureus may commandeer Propionibacterium acnes, a key member of the human skin microbiome, to spread its invasion and highlight two secretory virulence factors (S. aureus β-hemolysin and P. acnes CAMP (Christie, Atkins, Munch-Peterson) factor) as potential molecular targets for immunotherapy against S. aureus infection. Our data demonstrate that the hemolysis and cytolysis by S. aureus were noticeably augmented when S. aureus was grown with P. acnes. The augmentation was significantly abrogated when the P. acnes CAMP factor was neutralized or β-hemolysin of S. aureus was mutated. In addition, the hemolysis and cytolysis of recombinant β-hemolysin were markedly enhanced by recombinant CAMP factor. Furthermore, P. acnes exacerbated S. aureus-induced skin lesions in vivo. The combination of CAMP factor neutralization and β-hemolysin immunization cooperatively suppressed the skin lesions caused by coinfection of P. acnes and S. aureus. These observations suggest a previously unreported immunotherapy targeting the interaction of S. aureus with a skin commensal.     

Barrier creams – skin protectants: can you protect skin?

Barrier creams (BC) are used in hand care to protect the user against damage from surfactants and other irritants; their clinical value remains debatable; some reports indicate that inappropriate BC application might induce a deleterious rather than a beneficial effect. Since many cosmetic formulations contain 'skin protectants', we review concept, application, and efficacy from the pertinent scientific literature.     

'Nosing Around' the human skin: What information is concealed in skin odour?

In today's world, natural body odour is mostly considered as being unpleasant and combated by intensive cleansing, deodorants and perfumes. However, there is evidence that volatile body compounds provide the recipient with important information. Here, we present the chemical identity of odorous compounds derived from odourless precursors within sweat and sebum. Moreover, distinct volatile markers may be relevant for the clinical diagnosis of disease. Interestingly, ageing seems to correlate with the appearance of specific compounds that convey the so-called old man smell. Finally, it is discussed if human skin odour has the quality to act as pheromone transmitting information between individuals in terms of major histocompatibility complex type or reproductive status.     

Homocysteine may accelerate skin aging: a new chapter in the biology of skin senescence?

Skin aging has received tremendous attention in recent years by both scientists and the lay public. This article reviews the evidence that homocysteine, an intermediary sulfhydryl-containing amino acid implicated in atherosclerosis, can accelerate skin aging and the aging of internal organs (universal aging).     

Structure and function of the skin. Are there differences between black and white skin?

In concluding my remarks on structure and function of the skin, I wish to make one additional observation. Most dermatologists have acknowledged the role of the skin and its ability to protect the human organism from invasion by pathogenic organisms. There is good scientific evidence that skin plays an important protective role. Although an intact epidermis is of utmost importance as a protective unit, the contribution of the "acid mantle" is of considerable magnitude. The acidity or alkalinity and stability of this mantle is contributed to, in large measure, by the presence of eccrine gland secretions and sebaceous gland secretions. It is then not logical to assume that if black skin contains larger numbers of large and overly active adnexal glands, it would have a most effective mechanism for control of bacterial, viral, and other infections? That this is not the situation becomes apparent in the discussions that follow on cutaneous infections in black skin.     

Sunscreens inadequately protect against ultraviolet-A-induced free radicals in skin: implications for skin aging and melanoma?

Sunscreens are employed to mitigate the adverse effects of sunlight on skin but are primarily designed to prevent ultraviolet-B-associated burning and damage. The increasingly recognized role of ultraviolet A in aging, and possibly melanoma, highlights the need to include ultraviolet A screens; however, validation remains difficult. We have used a novel method to establish the efficacy of sunscreens, by measuring ultraviolet-A-induced free-radical production (thought to contribute towards ultraviolet-A-related aging and malignant change). Electron spin resonance spectroscopy was used to detect free radicals directly in human Caucasian skin during irradiation with levels of ultraviolet comparable to solar intensities. Using this system the protection afforded by three high factor sunscreens (sun protection factor 20+) that claim ultraviolet A protection was examined. Each sunscreen behaved similarly: at recommended application levels (> or = 2 mg per cm2) the ultraviolet-induced free radicals were reduced by only about 55%, and by about 45% at 0.5-1.5 mg per cm (0.5 mg per cm2 reported for common usage). A "free-radical protection factor" calculated on the basis of these results was only 2 at the recommended application level, which contrasts strongly with the erythema-based sun protection factors (mainly indicative of ultraviolet B protection) quoted by the manufacturers (20+). The disparity between these protection factors suggests that prolonged sunbathing (encouraged by use of these creams) would disproportionately increase exposure to ultraviolet A and consequently the risk of ultraviolet-A-related skin damage.     

Human β-defensin-2 and skin diseases

Human β-defensin-2 (hBD-2) is an endogenous antimicrobial peptide recently found in the skin with broad-spectrum antimicrobial activity and unique mechanism of function. Recent studies have confirmed that the expression of hBD-2 is upregulated in the lesions of some dermatoses, such as psoriasis,acne vulgaris, verruca, dermatophytosis and basal cell carcinoma, etc. The susceptibility to bacterial and viral infections may be associated with the decreased or absent expression of hBD-2. Further researches into HBD-2will provide a new direction for the prevention and treatment of skin diseases.     

The antiproteolytic compound α 2 in human skin

Summary Monoclonal antibodies recognizing the antiproteolytic compound ₂-macroglobulin (MG) were used for immunohistological studies on normal human skin. MG-specific immunoreactivity was found to be localized to the papillary dermis and to be concentrated in the region of the epidermodermal junction. In view of these findings and the possible involvement of proteolytic enzymes and their inhibitors in blister formation, we asked whether MG occurs in the fluid of experimentally induced blisters. MG was identified (by western-blotting) and quantified (by a monoclonal antibody based enzyme immunoassay) in the fluid of experimentally induced suction blisters. Taken together, MG is present in such blister fluid in concentrations 6 times lower than in serum, but still in an antiproteolytic range. These findings allow suggestion of a possible role for the antiproteolytic compound MG in blister formation.     

Single‐pass CO2 laser skin resurfacing of light and dark skin: extended experience with 52 patients

BACKGROUND: Multiple‐pass carbon dioxide (CO₂) laser skin resurfacing has been a favored treatment modality for photodamaged and acne‐scarred skin over the past several years. Its association with numerous side effects and complications, particularly prolonged erythema and dyspigmentation, however, has dampened the initial enthusiasm reserved for its use. By reducing the laser‐associated tissue ablation depth and degree of thermal necrosis, it is possible that the incidence of these side effects can also be reduced.

PURPOSE: To evaluate the clinical efficacy and side effect profile of single‐pass CO₂ laser skin resurfacing in a large series of patients.

MATERIALS AND METHODS: A total of 52 consecutive patients (skin phototypes I–VI) with mild facial rhytides, atrophic scars, or infraorbital hyperpigmentation underwent single‐pass treatment with a high‐energy, pulsed CO₂ laser. Side effects to treatment were closely monitored and tabulated. Clinical improvement using a quartile grading scale was assessed independently by two masked medical evaluators at 1, 3, 6, and 12 months postoperatively.

RESULTS: Significant clinical improvement was seen in all patients, with peak improvement scores noted at 12 months. Greater clinical improvement was seen in patients with darker skin tones despite the near universal incidence of transient postoperative hyperpigmentation in these patients.

CONCLUSIONS: Single‐pass CO₂ laser skin resurfacing can improve the appearance of fine rhytides, mild atrophic scars, and infraorbital hyperpigmentation in all skin types. The severity and duration of side effects and complications are reduced with this technique (compared with multiple‐pass procedures) and may offer a possible solution to the problem of treating patients with darker complexions.     

Microchimerism and skin disease: true-true unrelated?

Microchimerism, the stable presence of foreign cells in an individual, may result from trafficking during pregnancy or from organ or hematopoietic transplantation, and has been hypothesized to cause autoimmunity and certain skin diseases. Yet microchimeric cells are found in normal individuals and may be important to tissue repair. Thus microchimerism may be common, and finding microchimeric cells in diseased as well as normal tissue may be a "true-true unrelated" situation.     

What is nonablative photorejuvenation of human skin?

Nonablative photorejuvenation has become an integral procedure in the emerging discipline of laser dermatologic surgery. The objective is to confine selectively, without any epidermal damage, thermal injury to the papillary, and upper reticular dermis leading to fibroblast activation and synthesis of new collagen and extracellular matrix material. The procedure results in minimal patient morbidity, no interference with lifestyle, and a low risk of complications, while providing a satisfying degree of rhytides reduction. Multiple devices have been studied and marketed for nonablative photorejuvenation of human skin. However, currently, nonablative photorejuvenation should not be considered an alternative to laser skin resurfacing. The skin surface is not removed or modified. What really occurs may be more accurately referred to as dermal "remodeling" or "toning" as a wound healing response is initiated and collagen regenerated. The narrow "therapeutic window" of laser-induced dermal heating and epidermal cooling must still be optimized so that effective treatments can be obtained routinely. Clinical verification of effective treatment parameters (irradiation wavelength, pulse structure, radiant exposure, cooling time) will be obtained through further human studies. Most importantly, understanding the relationship between the degree of dermal thermal injury and synthesis of new collagen and extracellular matrix material will be fundamental to predicting the clinical efficacy and limitations of nonablative photorejuvenation.