Evidence and conjecture about mechanisms of cutaneous disease in photodermatology.

Photosensitivity disorders are caused by a variety of mechanisms. Three common themes are as follows: excess chromophore allowing visible light energy to cause photodynamic damage, reduced DNA repair capacity to UV-induced DNA damage, and enhanced sensitivity to light-induced allergens mediated immunologically. Although the cause of each condition may be known, the precise pathogenesis underlying the photosensitivity has taken longer to understand. By focussing on three clinical disorders under each of these themes, we have explored the following: why erythropoietic protoporphyria differs so markedly from the other cutaneous porphyrias; how a DNA repair defect was eventually revealed to be the underlying cause of the vitamin B3 deficiency disorder of pellagra; an immunological explanation for the over reactivity to photoallergens in chronic actinic dermatitis.

Molluscum contagiosum virus infection.

Molluscum contagiosum virus is an important human skin pathogen: it can cause disfigurement and suffering in children, in adults it is less common and often sexually transmitted. Extensive and persistent skin infection with the virus can indicate underlying immunodeficiency. Traditional ablative therapies have not been compared directly with newer immune-modulating and specific antiviral therapies. Advances in research raise the prospect of new approaches to treatment informed by the biology of the virus; in human skin, the infection is localised in the epidermal layers, where it induces a typical, complex hyperproliferative lesion with an abundance of virus particles but a conspicuous absence of immune effectors. Functional studies of the viral genome have revealed effects on cellular pathways involved in the cell cycle, innate immunity, inflammation, and cell death. Extensive lesions caused by molluscum contagiosum can occur in patients with DOCK8 deficiency-a genetic disorder affecting migration of dendritic and specialised T cells in skin. Sudden disappearance of lesions is the consequence of a vigorous immune response in healthy people. Further study of the unique features of infection with molluscum contagiosum virus could give fundamental insight into the nature of skin immunity.

Validation of a novel high-intensity LED light source for skin phototesting at 365 nm.

BACKGROUND: The gold standard for investigation of patients with suspected photosensitivity involves phototesting on non-exposed skin with an irradiation monochromator (IM). However, this device is bulky, expensive and only available at a small number of specialised photodermatology units. We have developed a small handheld high output monochromatic light source for phototesting to UVA at 365 nm using light-emitting diodes (LEDs). METHODS: A UNO light engine (Enfis, Swansea, UK) at 365 nm was used to develop a handheld intense source. Seventy-seven normal healthy volunteers were phototested on the lower back with the LED source and with an IM at 365 nm. Minimal erythema dose (MED) at 24 h was assessed visually and by a diffuse reflectance erythemameter. RESULTS: In 77 volunteers, MED levels for the two sources agreed in 66 out of 77 cases (85.7%). In a further 10 out of 77 patients, the measured MED elicited by the LED source was 1 dose level higher than the monochromator MED. CONCLUSION: A high-intensity portable and low cost LED phototesting device was developed. The results confirm that phototesting to UVA at 365 nm using this LED light source compares favourably to monochromator light testing at this wavelength.

Chronic inflammatory demyelinating polyradiculoneuropathy complicating anti TNF α therapy for chronic plaque psoriasis.

A 53-year-old woman with chronic plaque psoriasis treated with adalimumab (antitumour necrosis factor (anti TNF) α therapy) for 10 months presented with an 8 week history of hyperesthesia in a 'glove and stocking' distribution and clumsiness on walking. Nerve conduction studies confirmed the clinical diagnosis of a chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). She was admitted and treated with intravenous immunoglobulin and oral steroids and made an excellent recovery. To our knowledge, this is the first published report of CIDP associated with anti TNF α therapy given to treat psoriasis.

Vitiligo: concise evidence based guidelines on diagnosis and management.

Vitiligo is a common disease that causes a great degree of psychological distress. In its classical forms it is easily recognised and diagnosed. This review provides an evidence based outline of the management of vitiligo, particularly with the non-specialist in mind. Treatments for vitiligo are generally unsatisfactory. The initial approach to a patient who is thought to have vitiligo is to make a definite diagnosis, offer psychological support, and suggest supportive treatments such as the use of camouflage cosmetics and sunscreens, or in some cases after discussion the option of no treatment. Active therapies open to the non-specialist, after an explanation of potential side effects, include the topical use of potent or highly potent steroids or calcineurin inhibitors for a defined period of time (usually 2 months), following which an assessment is made to establish whether or not there has been a response. Patients whose condition is difficult to diagnose, unresponsive to straightforward treatments, or is causing psychological distress, are usually referred to a dermatologist. Specialist dermatology units have at their disposal phototherapy, either narrow band ultraviolet B or in some cases photochemotherapy, which is the most effective treatment presently available and can be considered for symmetrical types of vitiligo. Depigmenting treatments and possibly surgical approaches may be appropriate for vitiligo in selected cases. There is no evidence that presently available systemic treatments are helpful and safe in vitiligo. There is a need for further research into the causes of vitiligo, and into discovering better treatments.

Eye protection for ultraviolet B phototherapy and psoralen ultraviolet A patients.

BACKGROUND/PURPOSE: We tested eye protection used for phototherapy patients. The study also established current practice concerning eye protection in a sample of UK phototherapy units. METHODS: The ultraviolet (UV) transmission spectra of 30 'UV protective' contact lenses were measured at 5 nm intervals between 290 and 400 nm. Sunglasses, small UV goggles and UV visors were tested between 270 and 420 nm. We surveyed the use of eye protection during phototherapy in 78 UK phototherapy units. RESULTS: All samples of sunglasses, eye protection goggles, visors and sunglasses comfortably passed previously published arbitrary limits of acceptability. Most contact lenses showed some protection in the UVB, but most had little or no UVA protection. Of 78 UK phototherapy units 21 (33%) use tinted goggles during UV exposures, two (3%) use a visor only, 28 (43%) use both and nine (14%) use clear plastic (probably polycarbonate) goggles. CONCLUSIONS: UV transmission for sunglasses and contact lenses is lower compared with samples tested 10 years ago. All samples of glasses, goggles and visors tested provided adequate protection in the UV range according to published arbitrary limits of acceptability. Most contact lenses did not provide significant UV protection in the UVA range.

Five-year follow-up of a randomized, prospective trial of topical methyl aminolevulinate photodynamic therapy vs surgery for nodular basal cell carcinoma.

OBJECTIVE: To compare 5-year lesion recurrence rates in primary nodular basal cell carcinoma treated with topical methyl aminolevulinate photodynamic therapy (PDT) or simple excision surgery. DESIGN: Prospective, randomized, multicenter study. SETTING: University hospital dermatology departments. PATIENTS: A total of 97 patients, 50 with 53 lesions treated with methyl aminolevulinate PDT and 47 with 52 lesions treated by excision surgery, were included in the per protocol analysis. Of the lesions treated with methyl aminolevulinate PDT and surgery, 49 and 52, respectively, showed complete clinical response at 3 months after treatment and were observed for long-term outcome evaluation. INTERVENTIONS: Topical methyl aminolevulinate cream, 160 mg/g, applied for 3 hours before illumination (75 J/cm(2) of red light at 570 to 670 nm) on 2 or 4 occasions (12 [23%] of 53 lesions); or excision surgery. MAIN OUTCOME MEASURES: Histologically confirmed lesion recurrence, sustained lesion complete response rate (time-to-event analysis), and investigator assessment of cosmetic outcome, 5 years after the last treatment. RESULTS: At 5 years, recurrence was documented in 7 (14%) of 49 lesions (95% confidence interval [CI], 6%-27%) treated with methyl aminolevulinate PDT vs 2 (4%) of 52 lesions (95% CI, 1%-13%) treated with excision surgery (P = .09). Estimated sustained lesion complete response rates were 76% (95% CI, 59%-87%) and 96% (95% CI, 84%-99%), respectively (P = .01). More patients treated with methyl aminolevulinate PDT than surgery had an excellent or good cosmetic outcome: 27 (87%) of 31 patients (95% CI, 70%-96%) vs 19 (54%) of 35 patients (95% CI, 37%-71%) (P = .007). CONCLUSIONS: Long-term follow-up indicates superior efficacy of surgery to methyl aminolevulinate PDT in nodular basal cell carcinoma. However, methyl aminolevulinate PDT is also an effective treatment for this indication and exhibits a more favorable cosmetic outcome.

Gene dosage analysis identifies large deletions of the FECH gene in 10% of families with erythropoietic protoporphyria.

Erythropoietic protoporphyria (EPP) is an inherited cutaneous porphyria characterized by partial deficiency of ferrochelatase (FECH), accumulation of protoporphyrin IX in erythrocytes, skin, and liver, and acute photosensitivity. Genetic counseling in EPP requires identification of FECH mutations, but current sequencing-based procedures fail to detect mutations in about one in six families. We have used gene dosage analysis by quantitative PCR to identify large deletions of the FECH gene in 19 (58%) of 33 unrelated UK patients with EPP in whom mutations could not be detected by sequencing. Seven deletions were identified, six of which were previously unreported. Breakpoints were identified for six deletions (c.1-7887-IVS1+2425insTTCA; c.1-9629-IVS1+2437; IVS2-1987-IVS4+352del; c.768-IVS7+244del; IVS7+2784-IVS9+108del; IVS6+2350-TGA+95del). Five breakpoints were in intronic repeat sequences (AluSc, AluSq, AluSx, L1MC4). The remaining deletion (Del Ex3-4) is likely to be a large insertion-deletion. Combining quantitative PCR with routine sequencing increased the sensitivity of mutation detection in 189 unrelated UK patients with EPP from 83% (95% CI: 76-87%) to 93% (CI: 88-96%) (P=0.003). Our findings show that large deletions of the FECH gene are an important cause of EPP. Gene dosage analysis should be incorporated into routine procedures for mutation detection in EPP.

Retrospective assessment of PASI 50 and PASI 75 attainment with a calcipotriol/betamethasone dipropionate ointment.

BACKGROUND: The US National Psoriasis Foundation recently recommended that PASI 50 and PASI 75 response rates be used in clinical trials to enable comparisons across studies of different psoriasis therapies. To date, these response rates have not been reported for the two-compound ointment containing calcipotriol and betamethasone dipropionate (Daivobet/Dovobet; LEO Pharma, Ballerup, Denmark). Further, in order to compare Daivobet with other therapeutics recently presented to the European regulatory authorities and the FDA, comparison with the biologicals, efalizumab, etanercept and alefacept, were also made. OBJECTIVES: To present the PASI 50 and PASI 75 results for the two-compound ointment containing calcipotriol and betamethasone dipropionate. METHODS: Data from six phase III studies conducted with the two-compound ointment were pooled and the PASI 50 and PASI 75 response rates calculated for patients with severe (PASI>or=17) or less severe disease (PASI<17) at treatment commencement. Results for the biological therapies, efalizumab, etanercept and alefacept, were obtained from relevant published phase III studies. RESULTS: PASI 50 and PASI 75 were achieved by more patients treated with the two-compound ointment than with the individual components. In patients with severe disease, the PASI 50 response rate after 4 weeks' treatment was 88.8% with the two-compound ointment, 69.2% with betamethasone dipropionate, 53.8% with calcipotriol, and 30.0% with ointment vehicle. In comparison, 12 weeks' treatment with the biologicals resulted in PASI 50 response rates of 59% with efalizumab, 74% with etanercept, and 56% with alefacept. CONCLUSIONS: The two-compound ointment is effective, producing a PASI 50 and PASI 75 response in greater than 80% and 50% of patients, respectively, regardless of psoriasis severity.

School in photodermatology: Smith-Lemli-Opitz syndrome.

The Smith-Lemli-Opitz syndrome has only recently been added to the small number of congenital disorders characterized by photosensitivity. The clinical features of this disorder are distinct from other photosensitivity syndromes. Details on the patho-mechanism of photosensitivity in the Smith-Lemli-Opitz syndrome have yet to be fully determined. However, preliminary evidence points to the deranged cholesterol metabolism that characterizes the syndrome as causal in this UVA-mediated photosensitivity disorder.