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Solar urticaria is a well defined although uncommon photosensitivity disorder, and is said to be the underlying cause of chronic urticaria in approximately 0.5% cases. In contrast, solar angioedema is seldom reported. We describe two patients with postulated solar angioedema, associated with clinical and/or phototest features of solar urticaria. Recognition of solar provocation of angioedema has important consequences for patient management.

Pityriasis rubra pilaris (PRP) is a rare papulosquamous condition with an estimated incidence of one in 35,000 to one in 50,000. Psoralen and ultraviolet A (UVA) therapy has been used in its treatment but some patients are reported to be clinically photosensitive. We describe the photoinvestigation of a patient with PRP in whom sensitivity to broadband UVA was demonstrated.

Ultraviolet radiation (UVR) causes a range of acute and chronic adverse cutaneous effects, in addition to some beneficial effects. In present times, the skin is generally exposed to higher levels of UVR, such that inherent defence mechanisms become overwhelmed. Complications, notably skin malignancies, show a serious rise in incidence. Since many effects of UVR are mediated through generation of reactive oxygen species, antioxidant supplementation provides a strategy to combat their excess generation, and hence reduce the clinical consequences. Human supplementation studies examining the potential of a range of oral agents to protect against UVR-induced skin effects show mixed results; further studies should examine whether certain subgroups of the population may show augmented benefit.

Background/purpose: Sunscreens are employed with the aim of reducing the deleterious effects of ultraviolet radiation (UVR), but little is known about their use in the UK., Methods: This questionnaire survey assessed attitudes to and usage of sunscreens in northwest England in 2000. Subjects (186 females and 102 males) were recruited from the waiting rooms of four general practices, with a high response rate of 97%., Results: Females were more frequent users of sunscreens than males, but only 35% females and 8% males reported their regular use. Twenty-two per cent of the study population did not use sunscreens at all, whereas 66% of subjects bought a sunscreen product once a year or less. Thirty-four per cent subjects reported experiencing sunburn in the last 2 years. Interestingly, more (60%) sunburns were found to occur at home in the UK than on holidays abroad, and these frequently occurred during outdoor activities other than deliberate sunbathing., Conclusion: There remains much scope for sunscreen education in the British public.

Topical psoralen plus ultraviolet A (PUVA) using 8-methoxypsoralen (8-MOP) bath solution is a well established and effective treatment in dermatology. The standard immersion time in the UK is 15 min, but a shorter bathing period could potentially increase treatment convenience. In order to examine the effect of reduction in immersion time on skin phototoxicity, we compared the erythemal response to UVA following 5 min and 15 min psoralen baths. The study was performed on the forearm skin of 7 healthy volunteers using an 8-MOP psoralen concentration of 2.6 mg/l. One forearm of each volunteer was soaked for 15 min and the other for 5 min, followed by immediate irradiation with a series of 10 doses of broadband UVA ranging from 0.1 J/cm2 to 6.9 J/cm2. At 72 h, the minimal phototoxic doses (MPDs) were noted and erythema readings (erythema index) were taken in triplicate with a reflectance instrument. The median MPD following 5 min immersion was 1.7 (range 0.7-2.7) J/cm2 compared with 1.0 (range 0.4-1.7) J/cm2 after 15 min treatment, with no significant difference. However, the mean slope of erythema dose-response on the 15-min treated side was significantly steeper than on the 5-min treated side, 0.036 and 0.021 respectively, P < 0.05. Hence, this preliminary work shows that reducing 8-MOP immersion time to 5 min reduces the erythemal response to UVA. It will clearly be necessary to examine the effect of a shortened immersion period on disease clearance before considering such a change to the topical PUVA regime.

Photosensitive patients are known to apply insufficient sunscreen and to neglect several prominently exposed skin sites. The aim of this study was to use fluorescence spectroscopy to assess the effect of education on sunscreen application technique in the short and longer term. Six patients with longstanding photosensitivity conditions were asked to apply an intrinsically fluorescent sunscreen to exposed skin, as they normally would on a sunny day. Detailed fluorescence measurements were taken from 70 sites on the head, neck and arms. Using the previously established dose-response relationship for cream fluorescence, measurements were converted to equivalent thicknesses of cream. Patients were told the results of their sunscreen application assessment and deficiencies in technique were highlighted. Following education, application technique was reassessed twice, after intervals of 2 weeks and 6 months. Before education, sunscreen application was poor with inadequate amounts applied, and prominently exposed sites including ears, temples and neck often missed. At 2 weeks following education, improved application was seen at all sites, and the improvement was sustained at 6 months. Overall, education improved sunscreen application from a baseline median sunscreen thickness of 0.11 mg/cm2 to 0.82 mg/cm2 at 2 weeks and 1.13 mg/cm2 at 6 months (P<0.0001). Notably, median sunscreen thickness on the face improved from a baseline of 0.33 mg/cm2 to 1.51 mg/cm2 at 6 months. These findings demonstrate the importance of careful instruction to patients concerning sunscreen application technique; failure to do this may result in overconfidence in the ability of a sunscreen to protect. The next step is to assess a larger number of photosensitive patients with different diagnoses and to see whether improved technique correlates with improvement in clinical features.

We have assessed the pattern of dermal endothelial adhesion molecule expression following broadband UVB irradiation in vivo and in vitro. Skin biopsies were taken from 4 human volunteers at baseline and at 4, 8 and 24 h post-irradiation with 2.5 minimal erythema doses of UVB. Sections were stained immunohistochemically for E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1). CD31 and neutrophil elastase. The effect of direct UVB irradiation on E-selectin, ICAM-1 and VCAM-1 was examined in a human dermal microvascular endothelial cell line, HMEC-1. Cultured HMEC-1 were irradiated with 2.5-40 mJ/cm2 of UVB, and assessed for adhesion molecule expression by immunofluorescence microscopy and fluorescence-activated cell sorter analysis. In vivo, E-selectin was minimally expressed on EC at baseline and was induced by 4 h following irradiation, P < 0.01. ICAM-1 was moderately expressed at baseline and appeared mildly induced at 24 h, although this did not reach statistical significance. VCAM-1 was weakly expressed in unirradiated skin while CD31 was moderately expressed, but neither was induced by UVB irradiation. A significant neutrophilic infiltrate appeared by 8 h and was maximal at 24 h, P < 0.05. Neutrophil infiltration correlated with E-selectin expression, r = 0.96. In HMEC-1, ICAM-1 was upregulated at 24 h post-irradiation, with an increase in mean channel fluorescence from 100% at baseline to 145 (SD12)% at 24 h, P < 0.05. No change was seen in expression of E-selectin, VCAM-1 or CD31. These studies support the involvement of endothelial adhesion molecules E-selectin and ICAM-1 in UVB-induced inflammation. Whereas ICAM-1 is upregulated by direct irradiation of endothelial cells, E-selectin stimulation appears to be an indirect effect.

Thirty-six subjects (dermatology patients and normal volunteers) were phototested on back and buttock skin to determine their erythemal response to a geometrically increasing series of doses of ultraviolet B (UVB) radiation. The minimal erythema doses (MED) were recorded at 24 h post-irradiation and dose-response curves were constructed. A significant difference in MED was found between the 2 sites, with a higher value for buttock skin (median 38 mJ/cm2) than for the back (median 25 mJ/cm2). The slopes of response for the 2 sites were, however, found to be comparable, and there was no correlation between the slope of dose response and sun-reactive skin type at either site. Buttock skin, representing the constitutional skin colour, may provide a useful site for phototesting, especially in otherwise tanned individuals, providing that full dose-response curves are analysed.