Corticosteroid-induced atrophy and barrier impairment measured by non-invasive methods in human skin.

BACKGROUND/AIMS: Atrophy is a distressing side effect of potent corticosteroids. After open application of a high potency steroid, we monitored atrophogenicity by a variety of non-invasive methods. METHODS: Volar forearms were treated twice daily for 3 or 4 weeks, with clobetasol propionate cream (Temovate). The following methods were used: 1) confocal microscopy, 2) transepidermal water loss (TEWL), 3) dimethyl sulfoxide whealing, 4) sodium hydroxide erosions, 5) analysis of stratum corneum lipids, and 6) B-scan ultrasound. RESULTS: Confocal microscopy revealed thinning of the epidermis, decreased microvasculature and decreased size of keratinocytes. Evaporimetry demonstrated transepidermal water loss. Whealing to dimethyl sulfoxide was enhanced. Sodium hydroxide erosions formed more quickly. The amount of ceramides, cholesterol, and free fatty acids was reduced. Ultrasound showed thinning of the dermis. CONCLUSION: Non-invasive methods are very useful for quantifying the atrophogenicity of topical corticosteroids.

Polarized light photography and videomicroscopy greatly enhance the capability of estimating the therapeuic response to a topical retinoid (adapalene) in acne vulgaris.

Assessment of improvement in acne lesions following treatment is often based on clinical evaluation and photographs. However, limitations are associated with this sublective evaluation, making it difficult to accurately review individual acne lesions and to observe early response to therapy. Conventional photographs do not allow us to visualize small lesions, and it can be difficult to differentiate inflammatory lesions as papules or small nodules. Our objective was to evaluate a new standardized method for tracking individual acne lesions based on photographs. The effect of adapalene gel 0.1% on both inflammatory and noninflammatory acne lesions was evaluated using this technique. Polarized light photography and videomicroscopy were used to record the evolution of acne lesions over a 16-week period in 5 volunteers with moderate acne vulgaris. During the first 4 weeks before treatment, acne lesions were evaluated on a 3-times weekly basis to establish a pattern of progression and determine the length of time to resolution. Sebum secretion rates were monitored using Sebutape adhesive patches applied to the forehead and both cheeks for 1 hour. After 4 weeks, adapalene gel 0.1% was used once daily at bedtime for 8 weeks; polarized light photography, videomicroscopy, and assessment of sebum production followed treatment response. This treatment period was followed by a further 4-week phase, after which acne lesions and sebum secretion rates were evaluated. Our results showed that the new methodology was appropriate to track acne lesions and allowed an accurate and more oblective evaluation of individual lesions. Using this methodology demonstrated that adapalene gel 0.1% causes rapid resolution of inflammatory and noninflammatory lesions. The probability of clearing inflammatory and noninflamma tory lesions during the treatment period increased, and the probability of new lesions appearing decreased. Sebum secretion rates declined in patients while on study drug, returning to near pretreatment levels following therapy cessation. Using sophisticated photography and videomicroscopy every other day proved to be a valuable, noninvasive, and reliable method of following response to adapalene treatment in patients with moderate acne vulgaris.

Digital fluorescence photography can assess the suppressive effect of benzoyl peroxide on Propionibacterium acnes.

BACKGROUND: Porphyrins produced by Propionibacterium acnes exhibit an orange-red fluorescence under UVA light. The amount of fluorescence can be estimated by digital fluorescence photography. OBJECTIVE: We thought that digital fluorescence photography would be a quicker and simpler method than bacteriologic culture to demonstrate depopulation of P acnes in sebaceous follicles. We used benzoyl peroxide to bring about rapid suppression of P acnes. METHODS: Benzoyl peroxide 10% was applied twice daily for 7 days to the faces of 9 subjects. Five subjects were untreated controls. Digital fluorescence photographs of cheek and nose, and scrub samples for quantitative recovery of P acnes from the cheek were taken at baseline, day 3, day 7 (end of treatment), and day 16 (regression phase). RESULTS: The effect of benzoyl peroxide against P acnes was clearly demonstrated both by culture and by fluorescence photography after only 3 days. Image analysis of porphyrin fluorescence correlated well with the decrease in P acnes density from scrub cultures. No further decrease was observed at day 7 (end of therapy). Ten days later there was a return to baseline values, although in some subjects these remained lower. CONCLUSION: Digital fluorescence photography is a reliable, fast, and easy screening technique to demonstrate the suppressive effect of topical antibacterial agents on P acnes.

Quantitative and ultrastructural analysis of inflammatory infiltrates in male pattern alopecia.

In order to determine whether lymphocytic inflammation around the lower infundibula in male pattern alopecia is incidental or a general phenomenon, we performed morphometric and ultrastructural analysis of inflammatory infiltrates in the transitional zones of the vertex and occipital hairy scalps of 19 patients with male pattern alopecia. Six normal subjects served as controls. The number of inflammatory infiltrates around the follicular infundibula of the alopecic vertices and non-alopecic occiputs of male pattern alopecia patients was significantly greater than the corresponding control value. The number of mast cells in the widened fibrous tracts in the vertices of male pattern alopecia patients was significantly greater than those in the adventitial fibrotic sheaths of control subjects and the non-alopecic occiputs of male pattern alopecia patients. These data support the idea that the inflammatory process may be, at least in part, responsible for the development of male pattern alopecia.

Comparative effects of retinoic acid, glycolic acid and a lipophilic derivative of salicylic acid on photodamaged epidermis.

BACKGROUND: Studies comparing purported antiaging compounds are rare. OBJECTIVE: To compare in a randomized, placebo-controlled double-blind study 10% glycolic acid (GA), 2% 2-hydroxy-5-octanoyl benzoic acid (beta-lipohydroxy acid, LSA) and 0.05% all-trans-retinoic acid (RA). METHODS: Women volunteers treated one forearm twice daily with one of the active products and the other one with the vehicle. Comparative evaluations of efficacy were made using histochemistry and quantitative immunohistochemistry. RESULTS: Improvement in the various epidermal compartments was the most prominent finding at the RA-treated site. The LSA-treated site also exhibited similar positive changes, although to a lesser degree. GA showed no significant effect. CONCLUSION: In the presently tested concentrations and formulations, RA had a beneficial impact upon the aging epidermis. LSA mimicked RA but with somewhat lesser efficacy. By contrast, GA appeared almost inactive.

Hypopigmented macules of photodamaged skin and their treatment with topical tretinoin.

Hypopigmented macules are frequently observed in the photodamaged skin of elderly people. We undertook to study and treat 2 types of hypomelanosis of photoaged skin. These lesions were: 1) idiopathic guttate hypomelanosis; and 2) macular hypomelanosis. Comparative studies included: 1) high-resolution photography using parallel polarized light, ultra-violet (UVA) and epiluminescence; 2) Silflo replicas for microtopography; and 3) suction device (Cutometer) for elasticity. Macular hypomelanosis was distinguishable from idiopathic guttate hypomelanosis because the macules were less white and less well demarcated. Glyphic markings were essentially absent in macular hypomelanosis, but variably effaced in idiopathic guttate hypomelanosis. Distensibility of the macules was characteristically low in proportion to the loss of glyphic markings. The chief histologic finding was the absence of melanin in basal keratinocytes. Macular hypomelanosis and idiopathic guttate hypomelanosis are probably related disorders along a spectrum of depigmentation. Treatment with tretinoin for 4 months restored the elasticity, the glyphic markings, with a partial restoration of pigmentation.

The sodium hydroxide erosion assay: a revision of the alkali resistance test.

Burckhardt proposed the alkali resistance method as a means of assessing the integrity of the stratum corneum barrier in 1947. Researchers after Burckhardt largely found the test unreliable and nonreproducible; it therefore fell into disuse worldwide. We have upgraded the procedure by exposing the skin to 1.0 M sodium hydroxide under strictly specified conditions for successive 1-min periods until the emergence of the first erosions, revealed by staining with nitrazine yellow. Histology showed that the erosions were follicular and limited to the epidermis. The test was highly reproducible and repeatable. We demonstrated the usefulness of the test in the following ways: (1) the erosion time increased with aging, correlating with a thickened horny layer; (2) as few as five Scotch tape strippings greatly decreased the erosion time, although transepidermal water loss was only slightly increased; (3) slight damage to the horny layer by a 24-h exposure to 0.01% sodium lauryl sulfate sharply reduced the erosion time; (4) the erosion time decreased after daily open applications for 3 weeks of clobetasol propionate, corresponding to the thinned horny layer; (5) daily applications of petrolatum increased the erosion time. This new version of the alkali resistance test, renamed the sodium hydroxide erosion assay, promises to be a useful tool for studying the horny layer barrier in healthy and diseased skin.

Assessment of the atrophogenicity of corticosteroids to human skin using non-invasive methods.

BACKGROUND/AIMS: Atrophy is the most common adverse effect of topical corticosteroids. The objective of this study was to determine whether atrophogenicity of a potent steroid could be demonstrated in a 3-week period of open application using non-invasive bioengineering methods. METHODS: Volar forearms were treated twice daily for 3 weeks with clobetasol propionate cream. The following methods were used: 1) B-scan ultrasound; 2) Silflo-replicas for microtopogra-phy; 3) scanning electron microscopy; 4) Cutometer for bio-mechanical assessments; 5) colorimetry for measuring skin color; 6) evaporimetry for transepidermal water loss; 7) polarized light photos; 8) sticky slides for corneocyte sizing; 9) D'Squames for estimating scaling; and 10) biopsies for histologic evaluation of atrophy RESULTS: After only 1 week, Silflo-replica showed that glyphic patterns had been partially obliterated. At the same time, ultrasound scans showed dermal thinning, which increased over the 3-week period. Extensibility by Cutometer decreased steadily during the treatment. Image analysis of ?Squames revealed an increase in scaliness. Evaporimetry showed an increase in trans-epidermal water loss. Atrophy was confirmed by histology. CONCLUSION: The use of non-invasive bioengineering techniques provides a powerful tool to monitor atrophogenicity in a short period of open applications.

A new model for assessing the damaging effects of soaps and surfactants on human stratum corneum.

To elucidate the damage to the horny layers of human skin produced by surfactants and soaps, we evaluated the cytological alterations of corneocytes using an in vitro assay. Suction blisters, 8 mm in diameter, were raised on the forearms of young adult Caucasoids. The roofs were cut off and the viable epidermis was removed. The discs of stratum corneum were then agitated for up to 6 h at 60 degrees C in 1% solution of five soap bars of differing irritancy. Additionally, individual examples of anionic, cationic and nonionic surfactants were similarly evaluated. Measurements of corneocytes included: (1) the number released with time (disaggregation), (2) size (swelling) and (3) morphologic degradation. The effects of the cationic and non-ionic surfactants did not differ significantly from those of distilled water. The anionic surfactant caused more release and less swelling and morphological change. The test soaps had vastly different effects on the structural integrity of the stratum corneum. The harsher ones caused greater disaggregation, more swelling and greater morphologic deterioration of corneocytes, whereas the milder ones had less marked effects on these parameters. This model would be a useful screening technique for formulating milder soaps and might also provide insights into the complex modes of action of surfactants on the stratum corneum.

Pretreatment of photoaged forearm skin with topical tretinoin accelerates healing of full-thickness wounds.

Pretreatment of skin with all-trans retinoic acid (tretinoin) has been shown to enhance wound healing. Previous studies have mainly used animal models to demonstrate this effect. We wanted to determine whether pretreatment could promote wound healing in severely photoaged dorsal forearm skin. Four elderly men with severely actinically damaged forearms were treated daily for 16 weeks. One arm was treated with 0.05-0.1% tretinoin cream (Retin A, Ortho), and the other with Purpose cream (Ortho) as a vehicle control. Four-millimetre punch biopsies were taken from both dorsal forearms prior to treatment. After 16 weeks, full-thickness 2-mm punch biopsies were taken from both sides. Serial photographs were taken, and healing of the wounds quantitatively assessed by image analysis. On the 11th day, the wounds were excised using a 4-mm biopsy punch. Biopsies were processed for light microscopy. After 16 weeks, the tretinoin-treated forearms showed moderate erythema and scaling. Polarized light photographs revealed multiple, red, vascularized foci and/or a diffuse network of small vessels. The histological effects were typical for tretinoin, i.e. compaction of the stratum corneum, epidermal acanthosis with correction of atypia, an increase in small vessels, and increased cellularity in the upper dermis. Purpose cream had no effect, either clinically or histologically. On the tretinoin-treated side, the wound areas were 35-37% smaller on days 1 and 4, and 47-50% smaller on days 6, 8, 11, compared with the controls. Clinically and histologically, reepithelialization occurred more rapidly. Thus tretinoin dramatically accelerated wound healing in photodamaged skin.

Determination of density of follicles on various regions of the face by cyanoacrylate biopsy: correlation with sebum output.

The density of follicles on various regions of the human face has received scant attention. We used cyanoacrylate follicular biopsies to determine the number of follicles on the forehead, cheek, chin and nose of 12 healthy adult white women. Sebum output was assessed on the same regions by means of Sebutape. The density of follicles and sebum output followed a centrolateral decreasing gradient. There was no correlation between these two parameters. These regional patterns are important for studies of the pathogenesis of common disorders of the face and their response to treatment.

Stratum corneum lipids in skin xerosis.

Lipids of the stratum corneum are implicated in cohesion and desquamation of the stratum corneum as well as in the maintenance of normal barrier function. Evidence linking the intercellular lipids to such processes has mainly been derived from studies on acquired or inherited diseases of lipid metabolism manifesting abnormalities in the structure and the function of the stratum corneum. We have studied the composition of stratum corneum lipids in clinically normal individuals with typical xerosis or 'winter dry skin' in order to establish if the lipid composition differs from that of normal individuals, showing no signs of xerosis. The amount of total stratum corneum lipids was not related to xerosis (22.0 +/- 1.8 micrograms/cm2 for normal skin, and 26.3 +/- 2.9 micrograms/cm2 for severe xerosis), and no correlation was evident between polar lipids, cholesterol sulfate (2.8 +/- 0.5% for normal skin, and 1.6 +/- 0.2% for severe xerosis), or ceramides types I-VI, and dry skin. It therefore appears that dramatic changes in stratum corneum lipids are not detectable in normal 'winter dry' skin. However, a decreased proportion of neutral lipids (sterol esters, triglycerides), coupled to increased amounts of free fatty acids, were found associated to the severity of dry skin. Apart from a decline in the sebaceous function and in esterases activity, winter dry skin does not appear to be associated to dramatic changes in polar stratum corneum lipids.

Age-associated changes in stratum corneum lipids and their relation to dryness.

Stratum corneum lipids (SCL) were collected on the right and left legs of 50 subjects of varying ages and skin dryness. The level of dryness and composition of the lipid was the same on both sides. While skin dryness continuously increased with age, the composition of SCL showed a constant profile from the 50s. Aging was mostly associated with a decrease in sterol esters and triglycerides. On the legs, the SCL do not seem to primarily govern the increased desquamative process which features xerosis.

Age differences in poison ivy dermatitis.

In both man and animals, cell-mediated immunity diminishes with advanced age. Because poison ivy is a very common allergy, we evaluated age-associated differences in the contact allergic reaction to Rhus. Oleoresin patch tests were applied to two age cohorts (18-25 versus 65-84) each of 14 healthy white subjects. In the elderly, the allergic reaction developed more slowly, the inflammatory response at peak was greatly diminished and the dermatitis lasted longer and seemed to be more pruritic.