Classification and evaluation of photodermatoses

Photodermatoses can be classified into five general categories: 1) idiopathic photodermatoses, including polymorphic light eruption (PMLE), actinic prurigo, hyroa vacciniforme, chronic actinic dermatitis, and solar urticaria; 2) photodermatoses which are secondary to exogenous agents, including phototoxic and photoallergic reactions; 3) photodermatoses secondary to endogenous agents, mainly the porphyrias; 4) photoexacerbated dermatoses, including autoimmune disease, infectious conditions, and nutritional deficiencies; and 5) genodermatoses. The initial step in evaluating a photosensitive patient is based on a directed personal and family history. The morphology of the eruption, phototests, and in some patients, photopatch tests are essential in focusing the diagnosis. Skin biopsies and laboratory investigations, such as antinuclear antibody (ANA) panels and porphyrin profiles, may be required to further confirm the diagnosis.     

Diagnosis and treatment of the common idiopathic photodermatoses

The idiopathic photodermatoses are the most common cause of photosensitivity and the commonest of these are polymorphic light eruption, actinic prurigo, chronic actinic dermatitis and solar urticaria. The clinical presentation, investigation and treatment of these four disorders are presented. Spontaneous improvement does occur.     

Analysis of photodermatoses seen in a predominantly Asian population at a photodermatology clinic in Singapore

BACKGROUND: The idiopathic photodermatoses have been reported to be rarer in tropical Singapore than in countries of higher latitude, with photoaggravated dermatoses and systemic phototoxicity making up most of the photodermatoses seen here. This study aims to reassess the spectrum of photodermatoses seen at the National Skin Centre, Singapore, compared with almost a decade ago, and analyse the clinical and photobiological characteristics, as compared with other countries. MATERIALS AND METHODS: We reviewed the clinical data of 141 patients phototested from January 2000 to December 2001, and analysed the epidemiological, clinical and photobiological features. RESULTS: Photosensitive dermatoses were diagnosed in 88% (124/141) of patients phototested. In those diagnosed with photodermatoses, polymorphic light eruption (PMLE) (28%) was the most common diagnosis, followed by photoaggravated dermatoses (26%), chronic actinic dermatitis (CAD) (15%), systemic phototoxicity (15%), solar urticaria (SU) (7%), actinic prurigo (AP) (5%) and photoallergic contact dermatitis (4%). Ethnic Indians appeared to be more predisposed to PMLE; AP was diagnosed only in ethnic Chinese. The other photodermatoses occurred proportionally in all racial groups. AP differed from that found in Caucasians, being of adult onset and persistent. Abnormal phototest results were obtained in all patients with CAD, SU and AP, but only in 56% and 49% of systemic phototoxicity and PMLE, respectively. CONCLUSION: Idiopathic photodermatoses are more commonly diagnosed in Singapore than a decade ago, while the incidence of systemic phototoxicity has remained stable. The spectrum of photodermatoses in our Asian population now approximates that seen in Caucasian cohorts.     

Idiopathic photodermatoses: clinical, diagnostic and therapeutic aspects

Idiopathic photodermatoses are a group of photosensitivity dermatoses, which are not very frequent with the exception of polymorphous light eruption. Therefore, their recognition may not be easy for dermatologists who are not familiar with photosensitivity diseases. LEARNING OBJECTIVE: The information in this review is intended for giving clinical, diagnostic and therapeutic clues for the correct management of patients. Clinical features will be described together with diagnostic relevant procedures and usual therapeutic measures.     

Benign summer light eruption and polymorphic light eruption: genetic and functional studies suggest that a revised nomenclature is required

New research indicates that polymorphic light eruption (PLE) is an autoimmune disease against an ultraviolet radiation-induced cutaneous antigen. PLE may even confer some protection against skin cancer later in life. This new information demands a reassessment of the precise nature and nomenclature of PLE. Benign summer light eruption (BSLE) (lucite estivale bénigne) is the name used in continental Europe, and particularly France, to describe a clinically short-lived, itchy, papular eruption particularly affecting young women after several hours of sunbathing at the beginning of summer or on sunny vacations. Clinically more prolonged forms of solar eruption, starting early in spring and persisting for long periods, have been known in France as polymorphic light eruption (PLE) (lucite polymorphe) ('European PLE'). Investigative studies, however, now suggest that BSLE and some cases of 'European PLE' are part of the same spectrum. In the Anglo-Saxon literature, they are lumped together as PLE ('Anglo-Saxon PLE'). The other cases of 'European PLE', which do not fall within the compass of 'Anglo-Saxon PLE', are, in the Anglo-Saxon literature, classified as either actinic prurigo (AP) (a genetically determined, prolonged, excoriated form of Anglo-Saxon PLE), or chronic actinic dermatitis (CAD) (a sunlight-induced eczema precisely resembling allergic contact dermatitis, apparently to an ultraviolet radiation-induced antigen). It is therefore proposed that: i. the European term BSLE be dropped and that these patients be reclassified within the spectrum of (Anglo-Saxon) PLE, ii. the European use of the term PLE ('European PLE') be discontinued, iii. those previously diagnosed as having 'European PLE' be reclassified as (Anglo-Saxon) PLE, AP or CAD, as appropriate. The benefits of such a change in nomenclature would be twofold, firstly a uniformity of terminology and secondly, and more importantly, terminology would then correlate better with our recently improved understanding of the pathogenesis of these disorders.     

Update on photodermatoses

Interactions with ultraviolet radiation (UVR) and chromophores in the skin happen on a daily basis. Photodermatoses, which are abnormal responses to UV exposure, can be classified into subgroups based on pathogenesis. This review will discuss the clinical features, pathogenesis, photobiologic evaluation, prognosis and therapies of the most common photodermatoses.     

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.     

Ultraviolet A1 phototherapy

Long-wavelength ultraviolet A (340-400 nm; UVA1) therapy is currently available in only a few dermatology departments. Equipment capable of delivering this waveband has been available since 1981, but it is only over the past decade that increasing numbers of studies assessing the potential of this as a therapy have been published. High-dose UVA1, which requires expensive and space-occupying apparatus, is effective as a monotherapy for acute flares of atopic dermatitis, but it has not yet been formally assessed as an adjunct, rather than as an alternative to conventional therapies including potent and very potent topical corticosteroids. Low-dose (which can be administered using a standard phototherapy cubicle fitted with appropriate lamps) and medium-dose UVA1 may be less effective for this indication. Another condition for which UVA1 is effective, and is particularly promising because we have no reliably effective treatment already, is localized scleroderma. It also appears to be effective in systemic lupus erythematosus (although it is not yet clear when it is indicated, and its safety needs to be assessed in more patients) and in polymorphic light eruption (although there have been no studies suggesting that UVA1 will have any advantages over standard prophylactic phototherapies). Open studies and case series suggest that UVA1 may prove beneficial for various other diseases, including cutaneous T-cell lymphoma, lichen sclerosus, keloids, systemic sclerosis and hand dermatitis. In the centres where it is available, UVA1 has already proved a useful addition to the range of phototherapies previously available. However, much more research is needed to confirm its efficacy for many of its potential indications, and to determine when and how it should be used.     

Evaluation of narrow band ultraviolet B phototherapy in the treatment of chronic actinic dermatitis in Chinese patients

Few studies have been conducted in chronic actinic dermatitis (CAD) treated with narrowband ultraviolet B (NB UVB) phototherapy, especially in Asian patients. We aim to evaluate the efficacy and safety of NB UVB phototherapy in Chinese patients with CAD. 19 CAD patients of Fitzpatrick skin phototype IV received NB UVB phototherapy in spring and treatments were given 3 times weekly with incremental dose and maintenance therapy was given twice weekly for 3–4 weeks. The mean initial, endpoint, and cumulative dose of NB UVB was 0.08, 0.33, and 6.0 J/cm², respectively. Patients totally received 27 times of treatments in average. 87.5% of previously ultraviolet B（UVB） sensitive patients and 75% of previously ultraviolet A（UVA） sensitive patients had normal or improved MED after phototherapy. The percentage of patients returned to normal UVB phototesting was higher than that of patients returned to normal UVA phototesting (68.8% vs. 37.5%). The mean 1‐week DLQI and the need for using immunosuppressive agents and antihistamines were significantly reduced after treatment (p < .01 or p < .05). In conclusion, prophylactic NB UVB phototherapy is effective and safe in treatment of CAD in Chinese patients with Fitzpatrick skin phototype IV.     

Artificial hardening for polymorphic light eruption: Practical points from ten years'' experience

The conservative approach of sunlight avoidance and broad-spectrum sunscreen is often disappointing in patients with moderate to severe polymorphic light eruption. A springtime course of prophylactic artificial hardening with ultraviolet B (UVB) phototherapy or psoralen plus ultraviolet A (PUVA) photochemotherapy will often allow patients to tolerate more sunlight and give them greater freedom during the summer. In this retrospective study we describe ten years' experience of such "desensitization" treatment. Individualized therapy with attention to detail will maximize the effectiveness of this treatment.     

Prevalence of photodermatosis in four regions at different altitudes in Yunnan province, China

Idiopathic photodermatoses are common diseases in dermatology clinics that are associated with ultraviolet (UV) irradiation. The group includes a few dermatoses such as polymorphous light eruption (PLE) and chronic actinic dermatitis (CAD). The prevalence of PLE and CAD in China has not been previously reported. To investigate the population-based prevalence of polymorphous light eruption (PLE) and chronic actinic dermatitis (CAD) in six minority groups living in four regions with significantly different altitudes in the Yunnan province, a questionnaire survey was administered to 4899 residents of random villages in Yuanjiang county (Dai and Hani minorities), Kunming city (Han people and Yi minority), Lijiang county (Naxi minority), and Shangri-La county (Zang minority). The altitudes of these counties are 380 m, 1870 m, 2410 m and 3280 m a.s.l., respectively. The results showed that, first, there were 2400 males (49.0%) and 2499 females (51.0%). The prevalence of PLE was 0.65% (32/4899), and the prevalence of CAD was 0.18% (9/4899). PLE was higher among females than males (3.8 vs 1, P < 0.01). The CAD prevalence was not significantly different between males and females (1.6 vs 1, P > 0.05). Second, the prevalence of PLE was increased in higher elevations regions compared to lower elevations (P < 0.01). However, the prevalence of CAD was not significantly different among the four regions (P > 0.05). Third, the mean times of sun exposure for PLE and CAD were 6.0 and 6.5 h/day, respectively. The mean durations of PLE and CAD were 5.8 years, and 6.6 years, respectively. The study demonstrated that the prevalence of PLE is higher than that of CAD in Yunnan, and that the prevalence of PLE is correlated with altitude.     

Photosensitivity: the 9-year experience at a Sydney contact dermatitis clinic

In this retrospective study, 81 patients with photosensitivity were referred to the Contact and Occupational Dermatitis Clinic at The Skin and Cancer Foundation Australia, in Sydney, between 1991 and 1999. Photoallergic contact dermatitis (PACD) was diagnosed in 39.5% of patients, with 87.5% of these reactions being to sunscreen chemicals. Polymorphic light eruption (PMLE) accounted for 19.7% of cases, drug photosensitivity 14.8%, and photoaggravated atopic dermatitis and chronic actinic dermatitis (CAD) each constituted 7.4%. Compared with overseas studies, there was a high incidence of PACD, possibly reflecting the referral bias and widespread use of sunscreens. The incidence of PMLE and CAD was less than studies from cooler climates overseas. No cause could be determined for three photosensitive patients.