Value of a novel Neisseria meningitidis--specific polymerase chain reaction assay in skin biopsy specimens as a diagnostic tool in chronic meningococcemia.

Background: Chronic meningococcemia (CM) is a diagnostic challenge. Skin lesions are frequent but in most cases nonspecific. Polymerase chain reaction (PCR)-based diagnosis has been validated in blood and cerebrospinal fluid for acute Neisseria meningitidis infection, in patients in whom routine microbiologic tests have failed to isolate the bacteria.

[Leprosy, a neurologic disease].

Leprosy is a treatable chronic infectious disease, caused by Mycobacterium leprae, not highly transmittable that affects mainly the skin and peripheral nerves. Often neglected because it is rare in western countries, it may be encountered in patients coming back from endemic areas. Diagnostic criteria include underpigmented patches with loss of sensation, thickened peripheral nerves and acid-fast bacilli on skin smears or biopsy material.

Effect of intense pulsed-light exposure on lipid peroxides and thymine dimers in human skin in vivo.

Background: Intense pulsed light (IPL) generates high-intensity short flashes of visible light and has been used for about 10 years to improve dermatological conditions such as telangiectasia, pigmented lesions, and skin aging. Although these systems deliver a moderate dose (10-30 J/cm(2)) of visible light, this dose is delivered during a short pulse (2-5 milliseconds), which implies a very high fluence rate (approximately 4000 W/cm(2)). For this reason, we speculated whether the Bunsen-Roscoe law of reciprocity could still be valid in these conditions.

Retinoids in cosmeceuticals.

Retinoids are natural and synthetic vitamin A derivatives. They are lipophilic molecules and easily penetrate the epidermis. Their biologically active forms can modulate the expression of genes involved in cellular differentiation and proliferation.

Topical calcineurin inhibitors decrease the production of UVB-induced thymine dimers from hairless mouse epidermis.

Background: An increased incidence of ultraviolet-light-related skin tumours is a well-known problem in patients undergoing posttransplantation immunosuppression with systemic calcineurin inhibitors such as cyclosporine A or tacrolimus. UV-related carcinogenesis as a consequence of long-term treatment of sun-exposed sites with topical calcineurin inhibitors is therefore of theoretical concern.

Results: In this study, we show that tacrolimus acts as a UVB filter when incorporated into liposome membranes.

Topical beta-carotene is converted to retinyl esters in human skin ex vivo and mouse skin in vivo.

Human epidermis contains endogenous retinoids (retinol and retinyl esters) and carotenoids (mostly beta-carotene). Previous studies have shown that the enzymes involved in retinoid metabolism are present in human epidermis. There is still a controversy about the presence in the skin of the enzymes able to convert beta-carotene into vitamin A (retinol), although a recent study demonstrated the conversion of beta-carotene into retinol in human cultured epidermal cells.

Induction of rosaceiform dermatitis during treatment of facial inflammatory dermatoses with tacrolimus ointment.

Background: Tacrolimus ointment is increasingly used for anti-inflammatory treatment of sensitive areas such as the face, and recent observations indicate that the treatment is effective in steroid-aggravated rosacea and perioral dermatitis. We report on rosaceiform dermatitis as a complication of treatment with tacrolimus ointment.

Observations: Six adult patients with inflammatory facial dermatoses were treated with tacrolimus ointment because of the ineffectiveness of standard treatments.

Vitamin A exerts a photoprotective action in skin by absorbing ultraviolet B radiation.

Retinyl esters, a storage form of vitamin A, concentrate in the epidermis, and absorb ultraviolet radiation with a maximum at 325 nm. We wondered whether these absorbing properties of retinyl esters might have a biologically relevant filter activity. We first used an in vitro model to assess the photoprotective properties of retinyl palmitate.