Polymorphous Light Eruption

Demographics and clinical presentations of 844 patients with light and dark skin types with polymorphous light eruption and chronic actinic dermatitis evaluated over 23 years

INTRODUCTION

Polymorphous light eruption (PMLE) and chronic actinic dermatitis (CAD) have been classically described in White individuals, although recent studies have reported higher prevalence in patients with dark skin types, particularly African Americans.

OBJECTIVE

To evaluate for differences in demographic, and clinical features between persons with light and dark skin types who have PMLE and CAD.

METHODS

Retrospective review of patients with PMLE and CAD who were diagnosed from January 1, 1998, through November 31, 2021, at a single academic dermatology center.

RESULTS/DISCUSSION

A total of 844 patients (725 [85.9%] female; mean [SD] age of onset: 41.7 [16.9] years) were diagnosed with PMLE, and 60 patients (22 [36.6%] female; mean age, [SD]: 60.6 [10.6] years) of age at presentation, disease duration of 8.2 [7.3] years were diagnosed with CAD. Although just over 50% of the general clinic population was White, the prevalence of PMLE and CAD was significantly higher in dark-skinned individuals compared to light-skinned individuals (PMLE: 625 [74.0%] vs. 219 [25.9%], p value < .001; CAD: 43 [71.6%] vs. 17 [28.3%], p value = .003) respectively. The pinpoint papular variant of PMLE (PP-PMLE) was predominantly seen in dark-skinned individuals.

CONCLUSION

A substantial proportion of PMLE and CAD cases are present in dark-skinned individuals. PP-PMLE can be mistaken for lichen nitidus. As such, recognition of this entity is important for adequate evaluation and management of patients with PMLE.

Immunopathogenesis and management of polymorphic light eruption

Polymorphic light eruption (PLE) is the most common immunologically mediated photodermatosis, demonstrating many abnormalities caused by critical failure of ultraviolet (UV)-induced immunosuppression. The unique expression of antimicrobial peptides in PLE, which is most likely determined by alteration of microbiome components upon UV exposure, implicates their possible triggering role and pathogenic significance in the eruption. The review aims to clarify current knowledge regarding the immunological disturbances correlated with PLE that serve a base for better understanding of molecular pathogenesis of the disease and the development of new therapeutic strategies. Preventive treatment with broad-spectrum suncreens and sunscreens containing DNA repair enzymes, as well as natural photohardening with graduate exposure to sunlight in early spring could be sufficient in milder cases. Antioxidants and topical calcipotriol are promising approach for adjuvant prevention. Phototherapy, mainly with narrow band UVB rays, is more appropriate method in severe cases of the disease. The established treatment options for PLE include local and systemic glucocorticoids, systemic nonsedative antihistamines for itch relief, and rarely, immunosuppressive drugs in the refractory cases. Like medical photohardening, afamelanotide has the potential of photoprotection by inducing a melanization of the skin. Afamelanotide is believed to be a possible new treatment option for very severe and refractory cases of PLE. Targeting the main pruritogenic cytokine, IL-31, opens a new road for the development of novel therapeutic approaches to combat moderate and severe itching in cases of PLE with intense pruritus.

Polymorphous light eruption: clinic aspects and pathogenesis

Polymorphous light eruption is an immunologically mediated photodermatosis with high prevalence, particularly among young women in temperate climates, characterized by pruritic skin lesions of variable morphology, occurring in spring or early summer on sun-exposed body sites. A resistance to ultraviolet radiation (UVR)-induced immunosuppression and a subsequent delayed-type hypersensitivity response to a photoantigen have been suggested as key factors in the disease. Molecular and immunologic disturbances associated with disease pathogenesis include a failure of skin infiltration by neutrophils and other regulatory immune cells on UVR exposure linked to a disturbed cytokine microenvironment. Standard management is based on prevention.

Characterization of clinical photosensitivity in cutaneous lupus erythematosus

BACKGROUND

Photosensitivity (PS) in lupus erythematosus (LE) is frequently determined by patient report.

OBJECTIVE

We sought to characterize self-reported PS in cutaneous LE (CLE).

METHODS

The PS survey was used to classify subject responses into 5 phenotypes: direct sun-induced CLE flare (directCLE); general exacerbation of CLE (genCLE); polymorphic light eruption-like reactions (genSkin); general pruritus/paresthesias (genRxn); and sun-induced systemic symptoms (genSys). In all, 91 subjects with CLE alone or with CLE and systemic LE were interviewed.

RESULTS

In all, 81% ascribed to 1 or more PS phenotypes. CLE-specific reactions (direct sun-induced CLE flare or general exacerbation of CLE) were reported by 86% of photosensitive subjects. Higher CLE disease activity (measured by CLE Disease Area and Severity Index activity scores) was suggestive of direct sun-induced CLE flare reactions (P = .09). In all, 60% of photosensitive subjects described CLE-nonspecific reactions: polymorphic light eruption-like rash and general pruritus/paresthesias. These phenotypes often co-occurred with CLE-specific reactions and were predicted by more systemic disease activity as measured by Physicians Global Assessment (PGA) scores in regression analyses (genSkin, P = .02) and (genRxn, P = .05). In all, 36% of subjects reported systemic reactions and higher PGA scores were predictive of the sun-induced systemic symptoms phenotype (P = .02); a diagnosis of systemic LE was not (P = .14).

LIMITATIONS

PS was inferred from patient report and not directly observed.

CONCLUSIONS

Characterization of self-reported PS in LE reveals that patients experience combinations of CLE-specific, CLE-nonspecific, and systemic reactions to sunlight. Sun-induced CLE flares are associated with more active CLE disease. Polymorphic light eruption-like, generalized pruritus/paresthesias, and systemic reactions are associated with more active systemic disease. Recognition of PS phenotypes will permit improved definitions of clinical PS and allow for more precise investigation into its pathophysiology.

Management of polymorphous light eruption : clinical course, pathogenesis, diagnosis and intervention

Optimal management of patients with polymorphous light eruption (PLE), the most frequent photodermatosis, requires knowledge of the individual clinical course of the disease and pathogenic factors. As PLE often causes problems during leisure-time activities and holidays, resulting in a substantial loss of quality of life, prophylaxis is the most important therapeutic approach. Management of PLE must, therefore, focus on basic preventative measures and additional therapeutic approaches, depending on the clinical condition. PLE can be classified into four severity groups (mild, moderate-to-severe, severe and therapy-resistant), which are useful for determining appropriate prophylactic measurements. No specific laboratory tests are available for the diagnosis of PLE, therefore, a clinician must rely on the clinical appearance of the disorder (e.g. clinical symptoms, the location of the lesions, the relationship of the occurrence of the lesions with sun exposure and the time course of the lesions) as well as a patient's medical history in order to make a diagnosis. Basic preventative management of PLE consists of adequate sun protection comprising avoidance of sun exposure, the use of textile sun protection and the application of broadband sunscreens with high UVA protection potential. Other supportive measurements have to be managed individually and are dependent on the patient's medical history and the severity of the disease. Topical antioxidants, systemic immunomodulation, photo(chemo)therapy and systemic immunosuppression may be required in some cases of PLE. Topical antioxidants represent a new treatment approach for moderate-to-severe PLE and are an effective and well tolerated option for this patient population. Severe PLE also requires photo(chemo)therapy. Phototherapy can be in the form of 311 nm UVB or UVA1 irradiation. In cases where 311 nm UVB or UVA1 are ineffective, psoralen plus UVA (PUVA) bath therapy may be used. However, PUVA bath therapy must be used with caution because it is associated with acute and long-term adverse effects. In rare exceptions we would consider using oral PUVA therapy. However, in our outpatient department, quality of life of most patients is improved with the treatment regimens that are recommended for patients with moderate-to-severe PLE, without the need for photo(chemo)therapy.

Cutaneous diseases in Native Americans

Native Americans have a rich and complex heritage and culture. Although the genetic pool has changed with increasing integration with other Americans with different ancestry, there are important conditions that are unique to Native Americans, the most prominent example being actinic prurigo. The scientific literature dealing with Native American skin conditions is sparse and more studies are needed to understand more fully cutaneous disease in Native Americans.

[Photodermatoses during childhood]

Actinic dermatitis and phototoxic and idiopathic photodermatoses occur relatively often during childhood. Photodermatoses stemming from enzyme defects and genetic disorders are much less common, while photoallergic and chronic actinic dermatitis have not been dealt with to date. A specific sensitivity of a child's skin to light is often the first manifest clinical symptom of a photodermatosis, the key is to ensure early diagnosis. However, it is often difficult to reach a diagnosis, as the lesions are barely perceptible or have even healed by the time the patient is examined. This is why photoprovocation tests are so important in diagnosing photodermatoses, particularly during childhood. In addition to early diagnosis of these illnesses and offering the appropriate treatment, it is also crucial that the parents be well informed and aware of what symptoms to look for so that they can protect their children from overexposure to UV light and thereby avoid later actinic injuries that can become as serious as malignancies.

Thalidomide in dermatology

Thalidomide is an effective agent to treat over 25 seemingly unrelated dermatological conditions that have an inflammatory or autoimmune basis. The main side-effects of teratogenesis and peripheral neuropathy limit its use. Currently, in Australia no assurance is given as to the quality, safety and efficacy of thalidomide. The use of thalidomide for toxic epidermal necrolysis can lead to an increase in mortality, and its use as a prophylactic agent for the prevention of chronic graft-versus-host disease following bone marrow transplantation has raised more speculations as to the safety of this notorious drug. A review of the therapeutic indications for thalidomide in dermatology as well as the mechanisms of action and side-effects of this drug are presented. The current suggested guidelines for its use in clinical practice in Australia are discussed.

Actinic prurigo cheilitis: clinicopathologic analysis and therapeutic results in 116 cases

Objective. This study describes the clinicopathologic features and therapeutic results of 116 patients with actinic prurigo cheilitis seen over an 11-year period. Study Design. A retrospective study was carried out with hospital records and a microscopic slide review from a large dermatology department in Mexico City, Mexico. Results. The study consisted of 42 male (36.2%) and 74 female (63.8%) patients, with a male to female ratio of 1:1.7. Age ranged from 9 to 82 years (mean, 27.9 years; standard deviation, 14.2). Thirty-two cases (27.6%) were found in which cheilitis was the only manifestation of this condition. Pruritus, tingling, and pain of the vermilion were recorded in 96 cases (82.7%). Typical histopathologic findings included in most cases the presence of acanthosis, spongiosis, basal cell vacuolation, ulceration with serohematic crust formation, edema of the lamina propria, lymphocytic inflammatory infiltrate with well-defined lymphoid follicles, and variable numbers of eosinophils and melanophages. Improvement of the symptoms was obtained in 112 cases (96.5%) with sun-protective measures and diverse antiinflammatory agents. However, complete resolution of the labial lesions were more frequently achieved with the combination of topical steroids, thalidomide, and sun-protective measures (42.2%) as compared with topical steroid therapy plus sun-protection measures (16.3%; P <.005). Conclusion. Our findings confirm that lip lesions may appear as the only manifestations of this photodermatosis and that it has typical clinical and microscopic features and should therefore be considered a specific form of cheilitis.

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.

Phototoxicity and photoallergy

Photosensitivity may be phototoxic or photoallergic. Phototoxicity is much more common. There are 2 types of phototoxicity: photodynamic, which requires oxygen, and nonphotodynamic, which does not. Reactions induced by porphyrin molecules, coal tar derivatives, and many drugs are photodynamic. The reaction induced by psoralens, for the most part, is nonphotodynamic. Acute phototoxic reactions are characterized by erythema and edema followed by hyperpigmentation. Long-term ultraviolet phototoxicity results in chronic sun damage and skin cancer formation. Also, certain chemicals such as psoralen molecules and coal tar are photocarcinogenic. Phototoxic reactions to certain drugs produce unusual clinical patterns, that is lichenoid eruptions, dyschromia, photo-onycholysis, and pseudoporphyria. Photoallergy is an uncommon acquired altered reactivity dependent on an immediate antibody or a delayed cell mediated reaction. Solar urticaria is an example of the former, whereas photoallergy to exogenous chemicals is an example of the latter. Photoallergy to systemic drugs does occur but is difficult to characterize. The action spectrum for photoreactions to exogenous agents usually at least includes the ultraviolet A rays for both phototoxicity and photoallergy.

Drug photosensitivity, idiopathic photodermatoses, and sunscreens

Photosensitization may be defined as a process in which a reaction to normally innocuous radiation is induced by the introduction of a specific radiation-absorbing substance (the photosensitizer) that causes another component (the substrate) to be changed by the radiation. This review focuses on photosensitization produced by exogenous chemicals. Idiopathic photodermatoses, including polymorphous light eruption and its variants, solar urticaria and chronic actinic dermatitis, are also discussed. Clinical recognition patterns of the photodermatoses are stressed as well as several diagnostic procedures available for confirmation of the condition. Finally, descriptions, therapeutic uses, and adverse reactions of sunscreens are provided.

Actinic prurigo: clinical features and prognosis

BACKGROUND

Actinic prurigo, an idiopathic familial photodermatosis, has been described in Amerindians in Manitoba, Canada, as well as in the United States, Mexico, and South America.

OBJECTIVE

Our purpose was to describe the clinical features and prognosis of actinic prurigo in Amerindians in Saskatchewan, Canada.

METHODS

Clinical examinations, questionnaires, phototesting, and laboratory tests were used.

RESULTS

We present a series of 93 Amerindian patients. The face is the most commonly involved area. A hereditary tendency, cheilitis, and pruritus are prominent features. One third of patients report some lesions, often minor, during the winter. The majority of patients phototested were sensitive to ultraviolet A light.

CONCLUSION

We find the age of onset of actinic prurigo to be the most important feature in determining the type of eruption and the prognosis for the patient. In general the younger ages of onset (up to 20 years of age) are associated with cheilitis and more acute eruptions and are more likely to improve over 5 years. Those who develop actinic prurigo as adults (21 years of age and older) tend to have a milder and more persistent dermatosis.

Topical photoprotection for hereditary polymorphic light eruption of American Indians

We evaluated the photoprotective efficacy of a broad-spectrum sunscreen containing a UVA screen (butyl methoxydibenzoylmethane) and a UVB screen (octyl dimethyl p-aminobenzoic acid) in patients with hereditary polymorphic light eruption. At least 18 of the 30 patients who enrolled in the study were sensitive to sunlight through window glass, an indication of UVA sensitivity. Of the 21 patients who completed the clinical trial, the physician's evaluation was that 18 (86%) obtained good to excellent results. Self-evaluation by the patients revealed that 16 (76%) noted more photoprotection than from previous treatments.

HLA typing in polymorphous light eruption

Human leukocyte antigen typing of 41 white patients with polymorphous light eruption (limited concept) showed no significant differences when compared with the typing of 51 white control subjects. We previously found that actinic prurigo, an idiopathic photodermatosis particularly associated with Amerindians, has a positive association with antigens A24 and Cw4 and a negative association with A3. We suggest, on the basis of both laboratory and clinical findings, that polymorphous light eruption (limited concept) and actinic prurigo are two different and distinct diseases.

Photoaging/photodamage and photoprotection

Exposure to sunlight can produce both acute and long-term effects. Acute changes include erythema, photosensitivity, and immunologic alterations. Long-term consequences include carcinogenesis and photoaging. All effects can be minimized by photoprotection. This article reviews the adverse effects of sun exposure and strategies to reduce photodamage.

Cutaneous lesions in systemic lupus erythematosus

The spectrum of cutaneous lesions seen as a presenting feature or during the clinical course of systemic lupus erythematosus is described. Readers are acquainted with the histopathologic features, serologic associations, and pathogenesis when appropriate. Prognostic implications of individual cutaneous manifestations are also addressed.