The quality of life of 790 patients with photodermatoses.

BACKGROUND: Polymorphic light eruption and erythropoietic protoporphyria (EPP) have been demonstrated to have a moderate and large impact on the quality of life (QoL) of patients, respectively. However, there is little information available about the impact of other photodermatoses on QoL. OBJECTIVES: To assess and compare the impact of all forms of photodermatoses on patients' QoL using the standard 1-week Dermatology Life Quality Index (DLQI) questionnaire and a modified questionnaire to assess the impact over the previous year. METHODS: All patients with photodermatoses seen between 2001 and 2005 at five U.K. photobiology centres were contacted by post on the same day during a forecasted sunny week across the U.K. and asked to complete DLQI questionnaires. RESULTS: A total of 1877 patients were contacted. Seven hundred and ninety-seven (42%) patients replied, with a range from 30% to 48% for the five individual centres. Nearly two-thirds of patients with actinic prurigo (AP) and more than one-third of patients with photoaggravated dermatoses (PAD), chronic actinic dermatitis, EPP and solar urticaria had a DLQI of > 10, confirming a very large effect of the disorders on QoL. Of the cutaneous porphyrias, both variegate porphyria (median DLQI 3) and porphyria cutanea tarda (median DLQI 1.5) had a much lower impact on QoL than EPP. CONCLUSION: This is the first large-scale study to attempt to measure the impact of a range of photodermatoses on QoL. Photodermatoses have a major impact on QoL. This impact is highest in AP and PAD.

Response of human skin to ultraviolet radiation: dissociation of erythema and metabolic changes following sunscreen protection.

After UV irradiation of human skin there is an increase in epidermal and stratum corneum thickness and an increase in the thymidine autoradiographic labeling index. Previously we have demonstrated that persistent exposure to ultraviolet radiation (UVR) alters the distribution and activities of glucose-6-phosphate dehydrogenase (G-6-PDH) and succinic dehydrogenase (SDH) within the epidermis; G-6-PDH activity is increased over the whole epidermis and SDH activity is diminished in the granular cell area but increased in the basal layer. When skin is protected by an efficient sunscreen and irradiated with UVB, there is almost complete inhibition of the erythema normally seen following UVR exposure. In this study we have investigated the cytochemical, cell kinetic, and histometric changes that take place in the epidermis after UVB irradiation, with and without two different types of sunscreen. Some of the histometric and metabolic changes associated with UVB exposure were still evident despite sunscreen protection and the successful blocking of the erythema response. The implications of these findings are discussed together with the use of sunscreens to prevent development of solar damage.

Epidermal changes in human skin following irradiation with either UVB or UVA.

We have demonstrated previously that following UVB irradiation to normal volunteers there is an increase in epidermal and stratum corneum thickness and an increase in the thymidine autoradiographic labeling index. These changes are coupled with alterations in epidermal glucose-6-phosphate dehydrogenase and succinic dehydrogenase activities, despite the absence of erythema clinically. The use of a sunscreen did not completely prevent these changes. In this study, we have examined the effects of repeated irradiation of human skin with either UVB or UVA alone in order to compare the changes produced in the epidermis and to ascertain whether UVA irradiation could cause these. Irradiation with either UVB or UVA alone was found to increase the mean epidermal thickness, the mean stratum corneum thickness, and mean keratinocyte height significantly. Glucose-6-phosphate dehydrogenase activity was significantly increased throughout the epidermis, and succinic dehydrogenase activity was significantly decreased. The autoradiographic labeling index was significantly increased following UVB irradiation but not following UVA irradiation. These results demonstrate that UVA alone can have a direct effect on epidermal morphology and metabolism, suggesting that protection of skin from UV radiation should include adequate protection from UVA.

Expression of c-fos proto-oncogene mRNA in non-melanoma skin cancer.

c-fos is a member of the proto-oncogene family and is implicated in the modulation of cell proliferation and differentiation. Previous studies have shown that the c-fos gene expression is regulated in a tissue specific manner. In order to clarify the role of the c-fos gene in human epidermis, we have investigated c-fos mRNA expression in both normal skin and non-melanoma skin cancer. In normal skin the intensity of the c-fos mRNA expression in spinous cells was found to be stronger than that observed in basal cells. In lesions of solar keratosis and Bowen's disease the spinous cells also showed stronger c-fos mRNA expression than in basal cells. In two of four cases of Bowen's disease some upper spinous cells showed very strong mRNA expression of the c-fos gene. In squamous cell carcinomas studied there was considerable variation in the intensity of c-fos mRNA expression. Our findings indicate that the degree of c-fos mRNA expression is related to the degree of dysplasia present. In all cases of basal cell carcinoma examined the c-fos mRNA expression was markedly decreased. These results suggest that c-fos expression may be involved in the differentiation of human keratinocytes in vivo rather than in the neoplastic process itself.

The acute effects of ultraviolet-B radiation on c-myc and c-Ha ras expression in normal human epidermis.

It is well known that ultraviolet radiation (UVR) causes DNA damage due to the formation of photoproducts which result in the inhibition of DNA synthesis. It has been reported that DNA damage by physical agents such as UVR and chemical carcinogens induces alteration of certain gene expressions. Recently the transient induction of c-myc and c-Ha ras proto-oncogene expressions has been observed in a human keratinocyte cell line in vitro. The present study was designed to investigate whether the induction of these proto-oncogenes occurs in normal human epidermis after UVR in vivo and to relate these findings to DNA synthesis. C-myc and c-Ha ras transcripts were detected throughout human epidermis before and after UVR. C-myc expression increased significantly 5 h after two times the minimal erythema dose (2 x MED) of UVR, while DNA synthesis of the irradiated skin had recovered from the UVR-induced inhibition. The intensity of c-Ha ras expression remained unchanged at both 5 and 24 h after UVR. These results suggest that the c-myc gene plays an important role in the recovery of keratinocytes from acute damage following UVR.

Preparation of unfixed undemineralized bone sections: the Bright bone cryostat.

A bone cryostat is described with which cold sections of unfixed, undemineralized calcified tissue can be prepared. The bone cryostat is suitable for the preparation of the sections required for the histochemical and immunofluorescent study of bone, for electron microprobe analysis, and for bone and joint autoradiography with soluble compounds.

Measurement of section thickness in quantitative microscopy with special reference to enzyme histochemistry.

Quantitative histochemical techniques demand constancy in sectioning tissue and preferably knowledge of the true thickness of a section. In this investigation a simple, rapid, accurate, and reproducible technique is described for measuring section thickness using an instrument known as a Surfometer. It has been shown that: (a) cryostat microtome settings bear little relationship to the true section thickness of the sections produced; (b) that different instruments differ in their inaccuracies; (c) that this inaccuracy varies slightly with different tissues.If densitometric methods are used and either the absolute amount of a tissue component is to be measured or the amount of a tissue component is to be compared in two tissues then it is mandatory to determine the actual thickness of the section. The method described here seems the most appropriate one for these investigations.

Effect of zinc pyrithione on mitotic activity in normal human skin.

Two concentrations (0.02% and 0.002%) of zinc pyrithione (ZPT) in water and a water control were applied to normal forearms - both on normal skin (six subjects) and also where the skin had been stripped to the 'glistening layer' (six subjects) with adhesive tape. Measurements of labelling index (LI), mean epidermal thickness (MET), mean stratum-corneum thickness (MSCT), total epidermal thickness (TET) and basal/granular cell ratio (B/G) showed no significant differences between the three treatments on normal skin or the parameters studied in stripped skin. It is concluded that ZPT has no effect on epidermal renewal in normal skin in vivo.

Quantitative changes in respiratory enzyme activity in premalignant lesions and experimentally irradiated skin.

Chronic exposure of human skin to solar irradiation results in a variety of preneoplastic and frankly neoplastic skin lesions. We have shown that in solar keratoses (SK) and in paralesional skin there is instead of an even distribution of succinic dehydrogenase (SDH) activity a relative decreased activity in the granular cell layer. Furthermore, there is enhancement of the usual concentration of glucose-6-phosphate dehydrogenase (G6PDH) activity in the granular zone as well as an increase in total G6PDH epidermal activity. In the experimental part of this study, six normal volunteer subjects had areas of normally non exposed skin (buttocks) irradiated with a 2 Mean erythema dose of ultra violet light (290--400 nm) on between 3 and 5 occasions per week for 2--6 week periods. The results obtained indicated that the same changes in enzyme activity localization take place in artificially irradiated normally non exposed epidermis as seen in normally exposed skin nearby actinic keratoses. It is suggested that these quantitative changes may be the basis of a model for the study of chronic ultra violet light damage to the epidermis.

The effect of povidone-iodine paint on fungal infection.

Povidone-Iodine (Betadine) Paint was used in thirteen patients with a proven fungal infection. Ten patients had pityriasis versicolor, two had trichophyton rubrum and one M. canis. In the pityriasis versicolor group, seven out of the ten patients were either improved or cleared up completely within 7 days. There were no adverse reactions in this group of patients and the material proved quite acceptable to them. Scanning electron micrographs were carried out on three of the patients and demonstrated the decrease in fungal elements after treatment and clinical improvement.

Modulation of ultraviolet (UV) transmission by emollients: relevance to narrowband UVB phototherapy and psoralen plus UVA photochemotherapy.

BACKGROUND: Patients with psoriasis undergoing or about to undergo ultraviolet (UV) phototherapy and photochemotherapy often have thick scale on their plaques which can prevent the penetration of UV radiation. Emollients are used to moisturize the skin and to prevent or reduce some of the milder side-effects ('dryness', itching) sometimes experienced during UV therapy. However, emollients can alter the UV transmission of skin and thus may alter the clinical effects of phototherapy and photochemotherapy. OBJECTIVES: We tested 30 of the topical emollients in the British National Formulary (BNF) using a standard in vitro technique used to test sunscreens. We also surveyed U.K. phototherapy units to establish routine practice for emollient use in phototherapy and photochemotherapy. METHODS: We used a standard in vitro technique to measure the monochromatic protection factors (MPFs) of 30 non-bath emollients from the BNF. An application rate of 2 mg cm-2 was used. For the assessment of effects during narrowband UVB (TL-01) phototherapy, the mean of the protection factors at 310 and 315 nm was calculated; for psoralen plus UVA photochemotherapy the mean UVA protection factor was used. A questionnaire survey was used to assess routine practice concerning emollient use prior to phototherapies in phototherapy units throughout the U.K. RESULTS: In the UVA range, 17 of the 30 emollients gave protection factors of 1.2 or above. In the UVB range, 23 of 30 had an MPF of 1.2 or above. Yellow soft paraffin had the highest protection factor in the UVB range. Of 78 centres surveyed, 57 returned completed questionnaires (73%). Seventeen of 57 (30%) centres routinely used emollients immediately prior to administering phototherapy treatments. The remaining 40 of 57 (70%) did not. Forty-five (79%) responding centres recommended the use of emollients after phototherapy. CONCLUSIONS: This study has revealed considerable variability in the practice of emollient use before phototherapy treatments. Although the majority of centres included in this study did not routinely use emollients, almost one third did. Our in vitro measurement of 30 emollients revealed marked variation in UV transmission, with many emollients blocking sufficient UV to affect the response to therapy.

Photosensitive Smith-Lemli-Opitz syndrome is not caused by a single gene mutation: analysis of the gene encoding 7-dehydrocholesterol reductase in five U.K. families.

BACKGROUND: Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome characterized by a disorder in cholesterol metabolism. SLOS is caused by mutations in the DHCR7 gene which encodes 7-dehydrocholesterol reductase, an enzyme that catalyses the final step in cholesterol biosynthesis. We have previously established the clinical and photobiological features of the photosensitivity that is frequently a feature of SLOS. OBJECTIVES: In this study, we have performed mutational analysis of the DHCR7 gene in individuals from five families with SLOS. In each family, one member was affected by severe photosensitivity as a manifestation of SLOS. METHODS: Fifteen samples (including family controls) were screened using polymerase chain reaction amplification and direct automated sequencing. RESULTS: Six different DHCR7 mutations were identified of which five were single point mutations that caused missense amino acid substitutions (P51H, T93M, L99P, E448K and R450L). The other was a splice site mutation (G-->C in splice acceptor site) affecting the intron 8-exon 9 splice junction (IVS8-1 G-->C). This splice site mutation and four of the five missense mutations have been previously published as causal in SLOS but the P51H is a novel mutation which has not previously been reported. CONCLUSIONS: This is the first study in which DHCR7 gene mutational analysis has been performed on SLOS subjects with severe photosensitivity and indicates that no single mutation is responsible for the photosensitivity which characterizes this disorder.

Human stratum corneum as a substrate for in vitro sunscreen testing.

Synopsis In this study we have described the construction of a dedicated, inexpensive and portable instrument designed to evaluate sunscreens throughout the UVB and UVA range (290-400 nm). Both Transpore(TM) and an alternative substrate of readily obtainable human stratum corneum have been used as substrates on to which to spread the test products. The transmission of UVR through the substrate of stratum corneum was greater than through Transpore(TM) tape. Both substrates demonstrated a good correlation with in vivo or expected SPF results. However, in 10 out of the 11 sunscreens studied, the comparison of the two substrates demonstrated that the predicted SPF using Transpore(TM) tape was consistently higher than that using human stratum corneum. One sunscreen tested was alcohol based and as such was not suitable to test on Transpore(TM) tape. Predictions of SPF from products with SPF values less than 20 were not significantly different between substrates. However, product SPF values of greater than 20 demonstrated that Transpore(TM) tape overestimated the 'true'SPF. It is postulated that use of human stratum corneum in in vitro SPF testing systems more closely resembles that of human skin in vivo than does Transpore(TM) tape with regard to spreading and absorption of the potential sunscreen product. Résumé Cette étude décrit la construction d'un appareil portable bon marché servant àévaluer des écrans solaires sur les rayons UVA et UVB entre 290 et 400 nm. Le Transpore(TM) et le substrat alternatif d'un stratum corneum ont été utilisés comme substrats sur lesquels on a appliqué les produits tests. La transmission des rayons UVR à travers le substrat du stratum corneum était plus importante qu'à travers le Transpores(TM). Chaque substrat a montré une bonne corrélation avec les réultats des facteurs de protection solaire prévus ou in-vivo. Cependant sur 10 des 11 écrans solaires étudiés, la comparaison des deux substrats a montré que les résultats prévus de facteurs de protection solaires obtenus avec le ruban Transpore(TM)étaient considérablement plus élevés qu'avec le stratum corneum. Un des écrans solaires testé contenait de l'alcool et ne pouvait être testé sur le ruban Transpore(TM). Les prévisions de SPF avec des produits dont les valeurs SPF étaient inférieures à 20 n'ont pas montré de différences notables entre les substrats. Cependant les valeurs SPF supérieures à 20 ont montré que le Transpore(TM) surestimait le SPF réel. Il semble que l'utilisation de stratum corneum humain pour des tests de SPF in vitro corresponde mieux au comportement de la peau humaine in vivo que le Transpore pour l'application et l'absorption d'un écran solaire potentiel.

A quantitative histochemical study of three oxidative enzymes in solar keratoses and Bowen's disease.

Succinate dehydrogenase (SDH), glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) activities have been studied using quantitative enzyme histochemical techniques in the epidermis of five patients with solar keratoses and Bowen's disease. 'Non sun-exposed' buttock skin was compared with the skin from the actual lesion and adjacent, clinically normal paralesional skin. SDH activity was significantly increased in the basal layer and decreased in the granular layer in the epidermis of both lesion and paralesional skin, although the total epidermal activities were unchanged when compared to 'non-exposed' buttock skin. G6PDH activity was increased in the granular layer of paralesional epidermis and of lesions. No change in LDH activity was detected. Inclusion of phenazine methosulphate in the reaction mixtures resulted in a three-fold increase in formazan deposition without altering the localization. It is concluded that the quantitative changes and alteration in localization of SDH and G6PDH reported in solar keratoses are accompanied by similar changes in adjacent, clinically normal 'sun-exposed' skin and differ from normal 'non-exposed' skin. It is suggested that these changes may precede the development of the solar keratoses and that these findings may indicate a significant metabolic alteration in the events that lead to neoplasia.

Actinic keratoses and the epidermis on which they arise.

The appearance of the epidermis and epidermal autoradiographic labelling indices were compared in actinic keratoses and paralesional skin in seventeen patients after injection of tritiated thymidine. The skin on the buttock area was also studied as a "non-sun exposed" control. Labelling indices obtained from skin removed after 1 hwere as follows: actinic keratoses 17-4%; paralesional skin 11-2%; buttock skin 5-4%. Many of the epidermal cells in the keratoses that incorporated tritiated thymidine were bizarre and not restricted to the basal or suprabasal regions but were scattered through the thickness of the epidermis. Paralesional skin also showed epidermal thickening and cytological abnormalities including the formation of multinucleate epidermal cells. These findings suggest that the development of actinic keratoses takes place in epidermis that is itself abnormal. The changes suggest that there is a gradual stepwise progression of sun damage epidermis via the clinically obvious keratosis to squamous cell epithelioma.

Further studies on section thickness measurement.

A rapid, simple, accurate and reproducible technique for measuring section thickness using an instrument known as a surfometer is described. It has shown that microtome settings cannot be relied upon as a means of monitoring the thickness of sections of quenched or wax-embedded tissue. However, there appeared to be a linear relationship between microtome setting and the thickness of dewaxed sections. Microtome settings seem to provide an accurate indication of the thickness of araldite sections.

Surfometry. A method of evaluating the internal structure of the stratum corneum.

A method is described which enables measurement to be made of the roughness of the surfact of skin surface biopsies. The instrument used in this investigation has previously been employed to measure the degree of unevenness of metal and ceramic surfaces and is called a 'surfometer'. Using this technique the tracings that resulted from examination of normal skin, psoriasis and certain ichthyotic states could easily be distinguished. It was also demonstrated that there was a consistent pattern of change with increasing hydration of the stratum corneum in the absence of easily identifiable morphological alterations.

Derivation of a dysplasia index for epidermal neoplasia.

Measurements have been performed on histological sections of normal, paralesional and affected skin of patients with solar keratoses in an attempt at quantification of the degree of dysplasia. Features of dysplasia, including the epidermal thickness, the nuclear fraction and nuclear size distribution and shape, have been individually derived and incorporated into a formula designed to reflect the degree of dysplastic change within the epidermis. Application of this 'index of dysplasia' has been shown to differentiate lesional epidermis from that of the surrounding and normal non-sun-exposed skin. In addition, this index correlated well with independent dermatopathologists' assessments of the degree of dysplasia.

The effects of an aromatic retinoid (etretinate) on epidermal cell production and metabolism in normal and ichthyotic patients.

Normal subjects and ichthyotic patients were biopsied before and after etretinate (Tigason) therapy. Histometric and cell kinetic measurements showed minimal changes following treatment. The metabolic activity across the epidermis was measured by a novel approach using the Quantimet 720 image analyser, and was significantly increased in the normal subjects as demonstrated by glucose-6-phosphate dehydrogenase (G6PDH), succinic dehydrogenase (SDH) and non-specific esterase (NSE) activities. In the ichthyotics studied the levels of G6PDH and SDH activity were significantly lowered following etretinate therapy, to levels similar to those demonstrated in normal subjects. In contrast, the activity of NSE was increased in the ichthyotics after etretinate therapy. It is suggested that the effect of retinoids is to 'normalize' the process of epidermal differentiation when it is abnormal.