The clinical management of porphyria cutanea tarda: An update.

Porphyria cutanea tarda (PCT) is the commonest of the porphyrias (Semin Liver Dis 1998;18:67). It often occurs secondary to an underlying internal disorder, has significant impacts on liver health and longevity, and is a treatable disease. Thus, for the clinician, recognising the disease to make the correct diagnosis, identifying causative underlying diseases, and treating the porphyria and its complications, are crucial. Although reviews on the management of PCT have been written, there have recently been significant advances in the understanding of the factors predisposing to the disease, and of its wider health impacts. This review aims to help the clinician to diagnose and manage patients with PCT, with an emphasis on the impact of recent advances on clinical management.

Ultraviolet radiation exposure to the face in patients with xeroderma pigmentosum and healthy controls: applying a novel methodology to define photoprotection behaviour.

BACKGROUND: In xeroderma pigmentosum (XP), the main means of preventing skin and eye cancers is extreme protection against ultraviolet radiation (UVR). Protection is most important for the face. OBJECTIVES: We aimed to assess how well patients with XP adhere to medical advice to protect against UVR by objectively estimating the mean daily dose of UVR to the face. METHODS: We objectively estimated the UVR dose to the face in 36 patients with XP and 25 healthy individuals over 3 weeks in the summer. We used a new methodology which combined UVR dose measurements from a wrist-worn dosimeter with an activity diary record of face photoprotection behaviour for each 15-min period spent outside. A protection factor was associated with each behaviour, and the data were analysed using a negative binomial mixed-effects model. RESULTS: The mean daily UVR dose (weighted for DNA damage capacity) to the face in the patients with XP was 0·13 standard erythemal doses (SEDs) (mean in healthy individuals = 0·51 SED). There was wide variation between patients (range < 0·01-0·48 SED/day). Self-caring adult patients had a very similar UVR dose to the face as cared-for patients (0·13 vs. 0·12 SED/day), despite photoprotecting much more poorly when outside, because the self-caring adults were outside in daylight much less. CONCLUSIONS: Photoprotection behaviour varies widely within the XP group indicating that nonadherence to photoprotection advice is a significant issue. The timing and duration of going outside are as important as photoprotective measures taken when outside, to determine the UVR exposure to the face. This new methodology will be of value in identifying the sources of UVR exposure in other conditions in which facial UVR exposure is a key outcome, particularly in patients with multiple nonmelanoma skin cancers.

Ultraviolet A1 phototherapy: a British Photodermatology Group workshop report.

Whole-body ultraviolet (UV)A1 (340-400 nm) phototherapy was first introduced 30 years ago, but is currently available in the UK in only three dermatology departments. A workshop to discuss UVA1 was held by the British Photodermatology Group in May 2009, the aim of which was to provide an overview of UVA1 phototherapy and its role in practice, and to identify areas in which further studies are required. The conclusions were that UVA1 phototherapy is an effective treatment in several inflammatory skin diseases, including localized scleroderma and atopic eczema (AE); however, deficiencies and limitations exist in the published evidence base. For most diseases, such as AE, other treatments also exist, which are generally more effective than UVA1. However, for some diseases, particularly morphoea, the evidence of efficacy is stronger for UVA1 than for other treatments. Acute adverse effects of UVA1 are minimal. The risk of long-term adverse effects, particularly skin cancer, is unknown. Medium to high doses of UVA1 are needed for efficacy in most situations, but the equipment to deliver such doses is large, expensive and difficult to install. UVA1 is currently underprovided, and the recommendation of the workshop is that more tertiary centres should have access to UVA1 phototherapy in the UK.

Acquired erythropoietic protoporphyria as a result of myelodysplasia causing loss of chromosome 18.

We report a patient aged 73 years, who developed erythropoietic protoporphyria with typical photosensitivity, at the same time as she was diagnosed as having myelodysplastic syndrome. The myelodysplastic clone in her bone marrow completely lacked one of the two copies of chromosome 18. As chromosome 18 is the locus of the ferrochelatase gene, we postulate that this chromosomal deletion led to reduced synthesis of the enzyme in the bone marrow clone, so causing the porphyria. The nature of the remaining ferrochelatase allele was examined by polymorphism analysis and we discuss the insights that this patient's genotype may reveal about the pathogenesis of porphyria in myelodysplasia.

Erythropoietic protoporphyria (EPP) at 40. Where are we now?

Since Professor Magnus first defined erythropoietic protoporphyria (EPP) in 1961, there has been considerable progress in the understanding this disease. The past decade has been a period of spectacular progress in understanding the genetics and pathogenesis of the disease by molecular investigation. However, progress in therapy for EPP has been slower, and has been dogged by difficulty in assessing treatment efficacy in patients. We are now entering an era in which advances in molecular genetics are directly affecting patient management. This review summarises laboratory and clinical progress in EPP in the past 40 years, and assesses the potential impact of molecular biology on clinical practice.

Ferrochelatase gene polymorphism analysis for accurate genetic counselling in erythropoietic protoporphyria.

It has recently been shown that most cases of clinically overt erythropoietic protoporphyria (EPP) result from coinheritance of a mutated ferrochelatase gene and a commonly occurring low-expression normal variant allele. The identification of two polymorphic variant sequences associated with this low-expression allele now enables improved predictive counselling for couples where one partner has EPP. We describe a patient and his spouse in whom we have used such genetic analysis to provide an accurate estimate of the chance that their future offspring may suffer from EPP.