Normalized ultraviolet (UV) induction of Langerhans cell depletion and neutrophil infiltrates after artificial UVB hardening of patients with polymorphic light eruption

BACKGROUND: Ultraviolet (UV) B hardening has been widely used as a prophylactic treatment in patients with polymorphic light eruption (PLE). Recent investigations have shown that in patients with PLE Langerhans cells (LCs) and neutrophils display less migration from and to the epidermis after an intense UVB irradiation compared with controls. OBJECTIVES: To investigate the effect of UVB hardening of patients with PLE on their cell migratory responses after intense UVB exposure. METHODS: Thirteen patients with PLE were recruited and UVB provocation testing was performed before entering the study. Among these patients, seven developed PLE rash upon UVB provocation ('UVB-P') and the other six did not respond ('UVB-NP'). Eleven age/sex-matched controls were included. Buttock skin of all included individuals was exposed to 6 minimal erythema doses (MED) of UVB (TL-12 lamps). Biopsies were taken after 24 h and 48 h, together with one control biopsy of unirradiated skin. Patients received total-body UVB hardening therapy consisting of 12 irradiations, on average rising from 10% to 140% of the initial MED in 6 weeks. Subsequently, MEDs were reassessed and biopsies were taken from newly irradiated (6 MED UVB) and unirradiated buttock skin. Skin sections were stained for the presence of LCs, macrophages and neutrophils. The cross-sectional area (in percentage) of positively stained cells within the epidermis was assessed from patients before and after hardening and compared with controls. RESULTS: Before therapy, epidermal LC depletion and neutrophil influx at 48 h after 6 MED were most significantly reduced in 'UVB-P' patients (P = 0.025 and P =0.006, respectively) when compared with controls. 'UVB-NP' patients did not differ significantly from controls. After therapy, there were no longer any significant differences in the cell numbers among these three groups. CONCLUSIONS: UVB hardening significantly improves UV-induced cell migratory responses in patients with PLE. UVB provokability of PLE appears to be most strongly linked to reduced UVB-induced trafficking of LCs and neutrophils, and 'UVB-P' patients show normalization of these responses after UVB hardening.     

Haemorrhagic polymorphic light eruption: two cases of a rare variant

Polymorphic light eruption is a common photosensitivity disorder of unknown aetiology, that usually presents in the spring or summer months as an intermittent non-scarring, itchy erythematous, papulo-vesicular eruption. We present two cases of haemorrhagic polymorphic light eruption, a rare variant of this condition of which there are no case reports in the literature.     

Polychromatic phototest as a prognostic tool for polymorphic light eruption

BACKGROUND: Diagnosis of polymorphic light eruption (PLE) is based on the patient's history, the morphology of the lesions and the results of phototesting. Skin lesions of PLE can be provoked by repetitive UVB or UVA irradiation. However, about 20% of the patients with PLE have negative phototests. As 24% of the patients with PLE go into remission, it was of interest to search for a link between the results of the phototests and the evolution of the photodermatosis. METHODS: Forty patients with PLE were recruited and repetitive phototests were performed. To ensure a good reproducibility of the phototests, one to three phototests were performed on each patient at different stages of the disease including the period when the PLE had gone into remission. RESULTS: Except for one patient, there was a good reproducibility of the repetitive polychromatic phototests: in each patient, the tests remained positive or negative throughout the disease. After long-term follow-up, two different subgroups were identified: 30 patients with active PLE and 10 patients in remission. There were no clinical differences between these two groups apart from the age of onset and the clinical lesions of the PLE. PLE began at an earlier age in the patients in remission and presented mainly with a plaque-type eruption. In total, 52.5% of the patients had at least one positive polychromatic phototest. Phototests were positive only in patients with active disease. All the patients in remission had negative phototests. CONCLUSIONS: Repetitive phototests could be a prognostic marker for PLE. Two subtypes of PLE were identified on the basis of phototest results: the benign form of PLE with negative phototests, which tends to go into remission, and the more severe and more chronic PLE, with positive phototests.     

Population reference intervals for minimal erythemal doses in monochromator phototesting

Background/purpose: Monochromator phototesting, to measure the minimal erythemal dose (MED), is useful in investigating patients with abnormal photosensitivity at different wavelengths. It relies on access to reliable, up-to-date data on the MED in normal individuals. The purpose of this study was to determine MED in normal subjects at different wavebands and compare these with historical controls.
Methods: The study group consisted of 415 normal individuals (349 males) of skin types I–III living in Scotland. Age range was 18–83 years (median 31 years). Phototesting was performed using a monochromator at prescribed wavelengths from 295 to 430 nm. All calibrations were traceable to the National Physical Laboratory. Quality systems were maintained to ISO 9001 and ISO 17025 international standards and ultraviolet (UV) measurements accredited by the United Kingdom Accreditation Service (UKAS).
Results: The 95% reference interval (99% confidence interval for this) ranged from 6.8 to 27 mJ/cm² at 295 nm to >82 000 mJ/cm² at 430 nm.
Conclusions: Results of the current investigation are broadly in agreement with values published 25 years ago by this centre. This validates the phototesting process based on the use of monochromators with attention to careful control of conditions during UV exposure and MED reading, supported by dosimetric calibration.     

Characteristics of diagnosed polymorphous light eruption

BACKGROUND: The characteristics of polymorphous light eruption (PMLE) have been described in patients evaluated and diagnosed at specialized photodermatology centers. Our goal was to describe the characteristics of PMLE diagnosed in a general clinic setting. METHODS: We used electronic medical records to identify patients diagnosed with PMLE from 2000 to 2002 within a large group practice. We then collected additional information from medical records about patient demographics, lesion morphology, diagnostic testing, and therapies for the selected patients. RESULTS: We identified 142 patients with diagnosed PMLE. After manual chart review, we excluded 18 patients with other forms of photosensitivity, eczema, or collagen vascular disease. Eighty-percent of the remaining 124 patients were diagnosed by a dermatologist during the study period. Females predominated in our patient series and the mean age of PMLE onset was 37.8 years. Lesions were commonly described as papular, edematous papulare, papulo-vesicular, eczematous, and plaque-like. Few skin biopsies were performed, and no patient had phototesting or photopatch testing. Topical corticosteroids and antihistamines were the most commonly prescribed therapies. Only four patients were treated with phototherapy. CONCLUSIONS: Patient demographics and lesion morphology in our cohort were similar to other reports, but patterns of diagnostic testing and treatment were somewhat different than those observed in photodermatology clinics.     

Polymorphous light eruption

Polymorphous light eruption (PLE) is a common idiopathic photosensitivity disorder with an estimated prevalence of 10-20%. It is characterized by an intermittent skin reaction to ultraviolet (UV) radiation exposure, consisting of non-scarring pruritic erythematous papules, vesicles or plaques that develop on light-exposed skin. Despite the different morphology in different individuals, the eruption tends to have a monomorphous presentation in any single subject. The histopathological features of PLE are distinct and comprise a perivascular lymphocytic infiltrate in the dermis, subepidermal oedema and variable epidermal changes. The pathogenesis of PLE is not well known, but findings suggest that it is a delayed-type hypersensitivity reaction to one or more UV-modified cutaneous antigens. The principal action of PLE is mainly in the UVA region, although some subjects exhibit sensitivity to UVB alone or to both UVA and UVB radiation at the same time. Preventive measures in PLE include the regular use of photoprotective methods combined with graduated exposures to natural sunlight. The induction of immune tolerance by phototherapy and photochemotherapy are useful prophylactic methods in moderate to severe cases. The role of systemic agents in the management of PLE is under investigation. This article reviews the epidemiological, pathogenetic and clinical aspects of PLE and discusses recent advances in the diagnostic approach and management of this condition.     

Polymorphic light eruption

Polymorphic light eruption (PMLE) is the most common photodermatosis. It is typically characterized by nonscarring, pruritic, erythematous papules, plaques, or vesicles on sun-exposed skin that develop 30 minutes to several hours after sun exposure. The eruption may persist for a few hours to as long as 2 weeks. Females are affected two to three times more often than males. PMLE has been reported in all races, but tends to affect fair-skinned individuals with Fitzpatrick skin types I-IV most commonly. The pathogenesis of PMLE has been difficult to define, although it appears to be an immune-mediated delayed-type hypersensitivity reaction. Abnormalities of arachidonic acid metabolism and a possible correlation with lupus are other theories that are reviewed. Treatment options have been explored extensively. While "hardening" or desensitization of the skin through repeated irradiation seems to be the most effective, therapeutic options such as sun avoidance/sun protection, oral carotenoids, and antimalarials are also considered.     

Milia complicating bullous polymorphic light eruption

Polymorphic light eruption (PLE) is the most common photosensitivity disorder. Typically, PLE manifests in the spring or summer months as a recurrent pruritic papular and/or vesicular eruption occurring on photoexposed skin areas following sun exposure. The milia are caused by proliferative tendencies of the epithelium after injury. These may occur in areas of subepidermal bullous eruption. We report an original case of bullous PLE complicated by milia. Such association has not been reported previously.     

Lupus-like phototriggering in a young woman with benign summer light eruption

We report the case of a young woman with a single history of benign summer light eruption (BSLE) who developed delayed onset annular lupus-like lesions triggered by a polychromatic phototest, 6 weeks after the irradiation. BSLE of French authors is an idiopathic photodermatosis that corresponds to the minor form of polymorphic light eruption (PLE) of Anglo-Saxon authors. This patient may develop a true lupus erythematosus in the future as indicated by this lupus-like phototriggering and in view of the high prevalence of PLE in lupus patients.     

Provocation testing in polymorphic light eruption using fluorescent ultraviolet (UV) A and UVB lamps

BACKGROUND: Provocation testing is frequently performed during investigation of patients with suspected polymorphic light eruption (PLE). Techniques are not standardized between centres. OBJECTIVES: We sought to evaluate the efficacy of different fluorescent ultraviolet (UV) radiation lamps for provocation testing in PLE. METHODS: We analysed results in 68 patients referred consecutively for phototesting in whom a diagnosis of PLE seemed likely based on clinical history. Patients' case notes were reviewed and responses recorded to provocation testing on forearm skin over three consecutive days using broadband UVA, narrowband and broadband UVB lamps. RESULTS: A positive papular response to broadband UVA exposure was seen in 38 patients [56%, estimated 95% population confidence interval (CI) 43-67.9]. Thirty-four patients (50%) had a positive papular response to narrowband UVB exposure (95% CI 37.6-62.4). The probability of a positive provocation test following irradiation with both lamps was 80.9% (95% CI 69.5-89.4). From April 1999, 34 patients also had provocation testing with broadband UVB. Although six patients (18%) had a positive papular response, they all showed a positive response to one or both of the other lamp types. CONCLUSIONS: Provocation testing with fluorescent UVA and UVB lamps is a cheap and readily available method that can be used as a diagnostic aid to investigate patients with suspected PLE. Using both broadband UVA and narrowband UVB lamps for testing increases the likelihood of confirming the diagnosis than if either lamp is used alone.     

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.     

Antinuclear antibodies in patients with polymorphic light eruption: a long-term follow-up study

BACKGROUND: Previous studies have shown elevated titres of antinuclear antibodies (ANA) in 2.9-19% of patients with polymorphic light eruption (PLE). A diagnosis of lupus erythematosus (LE) was finally established in some of these ANA-positive patients. OBJECTIVES: To investigate whether the presence of ANA in patients with PLE merely represents an epiphenomenon or is associated with an increased risk of eventual progression to LE. METHODS: We identified 472 patients with PLE who had received prophylactic photo(chemo)therapy between 1986 and 2003 and were routinely tested for the presence of ANA. All ANA-positive (ANA titre of>or=1:80) patients were asked to attend for a follow-up examination comprising a medical history, complete skin inspection and a detailed laboratory analysis including ANA and antibodies against extractable nuclear antigens. RESULTS: Of all the patients, 55 (11.7%) were found to be ANA positive on one or several occasions, and three (0.6%) also had antibodies to SS-A/Ro. Thirty-nine (71%) of all ANA-positive patients including all Ro+ subjects were available for follow-up after a median follow-up period of 8 years (interquartile range 5-11.5). Twenty-five patients showed persistence of ANA positivity with a median titre of 1:160 (range 1:80-1:640), whereas in 14 patients ANA titres had returned to normal levels. None of the patients revealed additional clinical, histopathological or laboratory abnormalities suggestive of LE. CONCLUSIONS: After a median follow-up period of 8 years none of the ANA-positive patients developed LE. Our findings indicate that PLE is a benign disease without tendency to progress to LE.     

Photosensitive erythema multiforme and erythema multiforme-like polymorphous light eruption

BACKGROUND: Photosensitive erythema multiforme (EM) is a rare disorder. It usually occurs only if a herpes virus infection or ingestion of drugs precedes exposure to sunlight in selected patients. METHODS: We report a 37-year-old man who had recurrent EM eruptions following sun exposures over a period of 20 years. Lesions were prevalently located on exposed skin, but unexposed skin and mucosa of the oropharynx were also affected. The patient had poor tolerance to sunlight and denied having herpes simplex infection or using drugs. RESULTS: Provocative phototest induced clinically and histologically similar lesions at low dose thresholds of UVA (10 J/cm2) and UVB (100 mJ/cm2). CONCLUSION: On the basis of clinical and histological findings and results of phototesting, a diagnosis of photosensitive EM was made. The EM-like variant of polymorphous light eruption is discussed in the differential diagnosis.     

Polymorphous light eruption and benign summer light eruption in Italy

Background/purpose: Polymorphous light eruption (PLE) heterogeneity has been postulated, but the existence of benign summer light eruption (BSLE) is controversial. We studied the prevalence of the clinical patterns, criteria distinguishing BSLE from PLE, and diagnostic usefulness of phototest. Methods: Five Italian Photodermatology Centres recruited retrospectively 346 patients with typical clinical history and/or presentation of PLE. Age, gender, skin type, family history and presence of atopy were considered. UVA and UVB MEDs and provocative phototests with UVA and UVB were obtained with a standardized procedure. Photopatch tests were applied according to the IRCDG rules. ANA were assessed by indirect immunofluorescence. Results: Four criteria (predominance of women, shorter latency, uninvolvement of the face and absence of relapse during summer) identified BSLE in only 6.1% of cases. All had positive phototests, mostly with UVA. Uninvolvement of face, short latency and no seasonal relapses identified 11.7% patients, mostly with positive phototests to UVA. Short latency and no seasonal relapses in women identified 11.2% patients. Uninvolvement of face and no seasonal relapses in women identified 8.1% of patients. Uninvolvement of face and short latency in women identified 17.6% of patients. Conclusion: Criteria diagnosed BSLE in only a minority of patients, who were positive at phototesting, mostly with UVA.