Effect of topical corticosteroid application frequency on histamine-induced wheals

BACKGROUND: Very few studies have been conducted to assess the effect of corticosteroid application frequency to attain maximum benefit with minimum side-effects. OBJECTIVES: Compare the efficacy of twice-daily, once-daily and alternate-day applications of clobetasol propionate (0.05%) and compare whether an initial once-daily application followed by a subsequent alternate-day application is as effective as a once-daily application. METHODS: The ability of corticosteroids to suppress histamine-induced wheals on human skin was used as a human bioassay model. Of the 26 subjects included, 21 completed the 1st phase. In the 2nd phase, 11 subjects were included and all completed the study. Four sites were chosen on the left forearm. Clobetasol propionate (0.05%) was applied twice daily, once daily, and on alternate days, and on the control site a color, texture and odour-matched vehicle was applied. Prick test with histamine was carried out after 10 days. In the 2nd phase, clobetasol propionate (0.05%) was applied once daily for 14 days and compared with the initial once daily for 7 days and the subsequent alternate-day application for 7 days. Prick test was carried out after 14 days. RESULTS: The once-daily application of clobetasol propionate (0.05%) was as effective as the twice-daily application, but the alternate-day application was less effective than the once-daily application (P < 0.01). Also, the initial-daily and subsequent alternate-day applications were not as effective as the continuous once-daily application (P < 0.05). CONCLUSION: A once-daily application of clobetasol propionate (0.05%) is likely to provide the required therapeutic effect.     

Rapid effects of olopatadine hydrochloride on the histamine-induced skin responses

Olopatadine hydrochloride is one of the second-generation nonsedating antihistamines that are used for treating allergic disorders such as urticaria, rhinitis, and atopic dermatitis. We examined the inhibitory effects of this drug on the flare and wheal responses induced by histamine iontophoresis at 30, 60, and 90 min after oral administration in a double-blind, cross-over, and placebo-controlled study. Olopatadine hydrochloride significantly inhibited the histamine-induced flare and wheal responses as early as 60 min after oral administration when compared with placebo. Significant inihibitory effects of olopatadine hydrochloride on the itch responses were seen at 90 min after administration. Thus, olopatadine hydrochloride exhibited a very rapid and potent antihistamine effect on the histamine-induced skin responses.     

Effects of histamine receptor antagonists on histamine-induced responses in human skin.

The effects of intradermally administered histamine H1- and H2-receptor antagonists on the cutaneous responses--redness, weal, flare and itch--induced by intradermal injection of histamine were studied in man. Weal and redness were studied after blockade of the axon reflex by local infiltration with lidocaine. All responses were significantly inhibited by the H1-receptor antagonist mepyramine. The H2-antagonists cimetidine and metiamide reduced flare and itch significantly but not to the same extenet as mepyramine and not in a clearly dose-related manner. The size of weal and redness was not significantly reduced by cimetidine. No further reduction of flare, itch or weal was obtained by adding metiamide or cimetidine to mepyramine. After blockade of the axon reflex with lidocaine the histamine-induced weals turned white at the centre. This blanching was more prominent when histamine was injected in combination with cimetidine. Substituting mepyramine for cimetidine resulted in small weals with an intense red colour. It is concluded that, apart from being engaged in the direct vasodilatory response to histamine, H2-receptors do not seem to be involved in the other cutaneous responses to histamine studied.     

Dose-response relationship between objective measures of histamine-induced weals and dose of terfenadine.

Terfenadine is a safe non-sedative H1-receptor antagonist. This study aimed to quantify the relative reduction in weal and flare area, thickness and erythema at 4, 8, 12 and 24 h following a single but variable oral dose of terfenadine compared with pre-treatment measurements, in order to compare the dose-effect relationship and time course of the different dosages. In a double-blind randomized cross-over study, 12 healthy volunteers were given 60, 120 or 240 mg of terfenadine or placebo. Twenty micrograms of histamine acid phosphate was then injected intradermally at 4, 8, 12 and 24 h. The weal and flare areas were measured by planimetry, the thickness of the weal by an A-scan pulsed ultrasound device and the redness of both the weal and flare by an erythema-meter. A definite dose-response relationship was demonstrated between the weal and flare areas and the three active treatments. For the weal area, there was a significant difference between 60 mg and 240 mg of terfenadine at 4 h (p less than 0.01), at 8 and 12 h (p less than 0.05). For the flare area there was a similar significant difference at 4 h (p less than 0.01) and at 8 h (p less than 0.05). A dose-response relationship was demonstrated between weal erythema and 120 mg or 240 mg and 60 mg of terfenadine (p less than 0.05). There was a correlation between the plasma levels of the major metabolite and the initial dose of terfenadine, demonstrating their expected proportionality. This metabolite was also demonstrated in tissue fluid.     

Botulinum toxin type A reduces histamine-induced itch and vasomotor responses in human skin

Background Clinical evidence has revealed the antipruritic effect of botulinum toxin type A (BoNT/A). BoNT/A is believed to be effective against itch as it inhibits the release of acetylcholine as well as some other substances that may be involved in itch. Objectives To investigate the effect of subcutaneous administration of BoNT/A on experimentally histamine‐induced itch in human skin. Methods In this double‐blind, placebo‐controlled study, 14 healthy men (mean ± SD age 26·3 ± 2·6 years) received BoNT/A (Botox^®; Allergan, Irvine, CA, U.S.A.; 5 U) and isotonic saline on the volar surface of either forearm. Histamine prick tests were performed four times at the treatment sites (before treatment, and days 1, 3 and 7 after treatment). The itch intensity (as rated on a 0–10 visual analogue scale), itch area, neurogenic inflammation (visible flare area), blood flow (laser Doppler) and cutaneous temperature (thermographic images) were measured over the course of the trials. Results BoNT/A reduced the histamine‐induced itch intensity (F_1,39 = 30·2, P < 0·001) and itch area (F_1,39 = 8·8, P = 0·011) compared with saline at all time points after treatment. The duration of itch was also shorter for BoNT/A‐treated areas (F_1,39 = 19·4, P < 0·001), with a peak effect at day 7. The flare area was smaller in the BoNT/A‐treated arm compared with the saline‐treated arm at all time points after treatment (F_1,39 = 15·4, P = 0·002). Findings from blood flow (F_1,26 = 177·3, P < 0·001) and temperature measurements (F_1,26 = 27·6, P < 0·001) clearly showed the suppressive effect of BoNT/A on vasomotor reactions, with the maximal effect on days 3 and 7. Conclusions BoNT/A reduced the itch intensity, blood flow and neurogenic inflammation in response to the histamine prick test in human skin. The findings could be applicable in the treatment of some pruritic conditions that can be difficult to treat with conventional treatments.     

New insights into the nerve end organ of human skin

Bearing the sensory nerve end organ, the skin establishes contact to our environment. So far, the analysis of the cutaneous nervous system was dependent on the use of tissue serial sections. Because such samples inherently allow visualization of only a small part of the mainly horizontally oriented nervous system of the skin, we searched for possibilities enabling a more comprehensive view. Here, we present a method based on the immunostaining of dermal sheet preparations for subsequent analysis by electron microscopy and light, or laser scanning microscopy. We used antibodies against PgP9.5 and NCAM/CD56, both showing a regular network of fibers covering the entire superficial dermis. The bulk of free ending nerve fibers ramified within 25 µm of the dermo–epidermal junction, whereas below that only larger nerve bundles were present. Along the course of nerve fibers, we observed NCAM/CD56⁺ protrusions with diameters ranging from 5 to 15 µm. We further characterized these protrusions demonstrating the ultrastructural features of terminal non-myelinating Schwann cells ensheathing nerve fibres. Depending on the body region, we detected between 140 and over 300 individual terminal Schwann cells/mm² skin surface. In a double staining for NCAM/CD56 and vWF, we analyzed the topographical relationship of the nerve end organ to the blood vessels of the skin. In conclusion, this novel method allows for the first time a complex three-dimensional depiction of the cutaneous nervous system over several cm². Additionally, terminal Schwann cells can be studied in detail in situ for the first time. Furthermore, application of this method may provide new impetus in the investigation of the cutaneous nerve end organ under physiological and pathological conditions.     

Leukotriene- and histamine-induced increases in vascular permeability and interstitial transport in the skin

The aim of the present study was to investigate the edema induced by leukotriene D4 (LTD4). Edema is the gross effect of increased blood flow and capillary permeability. Our objective was to elucidate the effect of LTD4 on edema generation without the influence of the concomitantly increased blood flow induced by this potent vasodilator. A new method was outlined measuring the exudation through skin windows of a macromolecular tracer [( 131I]albumin) and a micromolecular tracer [( 99Tc]pertechnetat). Exudation of [131I]albumin is a function of enhanced vascular permeability and interstitial transport and blood flow, whereas that of [99Tc] pertechnetat is mainly a function of blood flow. Thus a ratio of the 2 exudate measurements gives a specific estimate of the changes in vascular permeability and interstitial transport. Histamine was employed to establish the method. A dose-response relation was found for histamine in the dose range of 10(-4) to 10(-7) M. The effect of 10(-5) M LTD4 on vascular permeability and interstitial transport of macromolecules was indistinguishable from that of histamine in the same concentration. This property together with their well-known vasodilatory capabilities indicate that the leukotrienes of the slow-reacting substance of anaphylaxis may play a role in the vascular changes in the allergic-inflammatory reaction.     

Perception of histamine-induced itch elicited in three different skin regions.

In order to investigate whether any regional difference in itch perception exists in experimentally induced pruritus, various concentrations of histamine (1, 3.3, 10, 33 and 100 micrograms/ml) were injected intradermally in three different skin regions in 15 healthy subjects. The regions were 1) the volar aspect of the forearm, 2) the lateral aspect of the upper arm and 3) the upper back at scapular level. Itch perception (itch latency, itch duration, maximal itch intensity, 'total itch index') and flare reactions were studied. A significant dose-response relationship was shown in each of the three regions for all itch variables, except itch latency, and for the flare reactions. However, no significant regional difference in itch perception was observed. The flare reaction showed a regional variation, with significantly smaller flares on the forearm than in the other two regions.     

Dynamic indentation on human skin in vivo: ageing effects

Background/purpose: Knowledge of the mechanical properties of the human skin is very important for cosmetic and clinical research. Objective and quantitative measurements are essential to compare studies performed by different experimenters in different centres. The aim of this paper is to present a method to measure the viscoelastic properties of human skin in vivo using dynamic indentation.
Methods: A complete device to assess the stiffness and damping of skin has been developed. The frequency and strain amplitude range from 10 to 60 Hz and from 1 to 10 μm. Tests on pure elastic inert materials have been performed to validate the device. An in vivo study including dynamic indentation, suction test, hydration measurement and topographic analysis has been performed on 46 subjects aged from 18 to 70 years, divided into three groups.
Results: Results on inert materials show the validity of the device developed. The mechanical behaviour of the skin can be described by a Kelvin–Voight model under dynamic indentation. A comparison with a suction test, hydration and topographic measurements shows that the stiffness and the damping measured by dynamic indentation correspond mainly to the natural tense state of the skin on the body due to the dermis. A weak correlation has been found between dynamic indentation and suction parameters. The complex modulus measured by dynamic indentation at 10 Hz frequency stress ranges from 7.2 ± 2.1 kPa for the oldest group to 10.7 ± 2.6 kPa for the youngest group.
Conclusion: The device presented gives convincing results. The measurement of stiffness and damping complements the viscoelastic phenomenological parameters of the suction test.     

Dual effects of CGRP-antagonist on allergic contact dermatitis in human skin

There is increasing evidence of an interaction between the nervous and the immune systems. The aim of this study was to investigate the rôle of calcitonin gene‐related peptide (CGRP) in the modulation of the elicitation of immediate and delayed, immunological and non‐immunological reactions in human skin. CGRP (13 pmol and 39 pmol), and the CGRP‐antagonist, CGRP_/8–37/, (50 pmol and 500 pmol) were injected intracutaneously prior to provocation tests. Patients with allergy to nickel were provoked with nickel sulfate epicutaneously, and the reactions were evaluated by a clinical scoring system (guidelines of the International Contact Dermatitis Research Group). Patients with allergy to birch pollen were provoked by a prick test with the allergen, and the volume of the weals was measured. The patients were also provoked with tuberculin (delayed immunologic reaction), benzalkonium chloride (irritant contact dermatitis), UV‐light and benzoic acid (non‐immunologic contact urticaria). The test reactions were estimated by planimetry. CGRP_/8–37/ exerted dual effects on allergic contact dermatitis, causing potentiation at a dose of 500 pmol (p=0.004) and inhibition at a dose of 50 pmol (p=0.012). Other reactions were not significantly affected by the pretreatments. The results suggest that CGRP participates in delayed inflammatory reactions, but is not involved in immediate immunologic reactions.     

Anti-ageing effects of alpha-naphthoflavone on normal and UVB-irradiated human skin fibroblasts

Ageing is a complex and multifactorial process resulting in several functional and aesthetic changes to the skin. We found that α-Naphthoflavone (α-NF) concentration-dependently induced pro-collagen type I protein expression and inhibited MMP-1 protein expression, in both normal and UVB-irradiated cells. SB431542 and SIS3 - inhibitors of TGF-β and Smad3, respectively - significantly alleviate α-NF-caused response of MMP-1 and pro-collagen. LY294002 (PI3K inhibitor) can reverse α-NF-induced ERK, Akt, Smad-3 activation, pro-collagen synthesis and α-NF-suppressed AP-1 activation. PD (ERK inhibitor) was not involved in pro-collagen generation and MMP-1 inhibition. We concluded that α-NF promotes pro-collagen production and inhibits MMP-1 expression via the activation of a PI3K/Akt/Smad-3 pathway in normal and UVB-irradiated human skin fibroblasts, while TGF-β may play an important role in transducing this pathway. These results suggest that α-NF, a natural plant product, has the potential to become a novel anti-ageing skin application.     

体外重建皮肤模型(老化模型)中特定的晚期糖化终末产物诱导的生物学效应

人皮肤老化的特征包括弹性纤维减少、不溶性胶原蛋白蓄积以及创伤修复能力受损等.而对于皮肤曝光部位,促炎性改变还能导致富含胶原蛋白基质的重构,进一步加重上述变化.该基质重构过程可通过两种方式实现.第一种涉及晚期糖化终末产物(AGE)的产生(由葡萄糖和羰基醛经过化学反应生成),可导致细胞外基质发生蛋白质交联、固化及失去弹性等损害.第二种涉及富含AGE的真皮基质与真皮细胞之间的相互作用,通过AGE受体(RAGE)和其他受体途径引起细胞活化,导致生长因子和细胞因子的释放,从而使细胞外基质发生深度重构.糖化修饰的基质环境下,二维模型培养的细胞中已观察到许多上述变化.欧莱雅已多年致力于体外重建皮肤模型研发,并证实对模型的基质成分进行糖化修饰,能够较好模拟老化皮肤的表型,与之有许多相似之处.已知老化皮肤中,AGE组成是多样的,该研究通过对胶原蛋白进行特定的糖化修饰,来探讨特定的糖化修饰在体外重建皮肤模型中所诱导的生物学效应.该文分析的胶原蛋白糖化修饰包括:N羧甲基赖氨酸(CML)、N羧乙基赖氨酸(CEL)、甲基乙二醛氢咪唑酮(MG-H1)以及戊糖素.     

Evaluation of effects of platelet-rich plasma on human facial skin

Abstract

Introduction: Platelet-rich plasma (PRP) has been used for rapid healing and tissue regeneration in many fields of medicine. This study was conducted to evaluate the effects of PRP application procedure on human facial skin. Methods: PRP was applied thrice at 2-week intervals on the face of ten healthy volunteers. It was applied to individual's forehead, malar area, and jaw by a dermaroller, and injected using a 27-gauge injector into the wrinkles of crow's feet. Participants were asked to grade on a scale from 0 to 5 for general appearance, skin firmness–sagging, wrinkle state and pigmentation disorder of their own face before each PRP procedure and 3 months after the last PRP procedure. While volunteers were evaluating their own face, they were also assessed by three different dermatologists at the same time by the same five-point scale. Results: There was statistically significant difference regarding the general appearance, skin firmness-sagging and wrinkle state according to the grading scale of the patients before and after three PRP applications. Whereas there was only statistically significant difference for the skin firmness–sagging according to the assessment of the dermatologists. Conclusion: PRP application could be considered as an effective procedure for facial skin rejuvenation.     

Some effects of calcitonin gene-related peptide in human skin and on histamine release

Calcitonin gene-related peptide (CGRP) produced a dose-related wheal and flare reaction in human skin at doses of 12.5 to 50 pmol. The flare response but not the wheal response to CGRP and substance P were inhibited by prior treatment of the subject with oral chlorpheniramine, 16 mg. CGRP, but not substance P, was potent in producing a delayed erythema and surrounding pallor in human skin, which peaked at 1 h and persisted for more than 3 h after injection, when wheal and flare responses had subsided. The delayed response was accompanied by infiltration of polymorphonuclear leukocytes. The delayed erythema and pallor produced in response to CGRP were not inhibited by oral chlorpheniramine, or by 4% prilocaine injected locally. CGRP released histamine from rat peritoneal mast cells over the concentration range 2.5-10 microM. CGRP was about fourfold less potent than substance P in releasing histamine. The substance P analogue, [D-Pro4, D-Trp7,9,10]SP4-11 10 microM, and benzalkonium chloride 10 microM inhibited histamine release from rat mast cells stimulated by either CGRP or substance P.     

Orally administered ethanol: transepidermal pathways and effects on the human skin barrier

Ethanol intake is associated with a variety of skin diseases. The aim of the present study was (1) to identify the pathways of release of orally administered ethanol through the skin, and (2) to investigate the effects of a single oral dose of ethanol on the penetration of topically applied substances into the skin. Ethanol evaporation via the skin was measured using the new technique of ion mobility spectrometry (IMS). Transepidermal water loss (TEWL) and skin surface temperature were simultaneously measured before and after ethanol consumption. Measurements were performed on skin sites with different stratum corneum (SC) thickness, and density of follicles and sweat glands. These appendages were selectively sealed to investigate their participation in ethanol evaporation. The penetration of a topically applied UV filter substance was studied before and after ethanol consumption after removing the SC with adhesive tape. Ethanol evaporation was measured within 5 min of consumption, while the skin surface temperature remained nearly constant. The sealing of the appendages did not have a significant effect on ethanol evaporation. On the forehead, a higher TEWL value was measured than on the forearm. On both skin sites, an increase in TEWL was observed after ethanol ingestion. No influence of orally administered ethanol on the penetration of the topically applied UV filter substance was observed. The results indicate that ethanol evaporation occurs via the lipid layers without a significant effect on the penetration of the topically applied substance.