Polymorphous light eruption

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Polymorphous light eruption
Other namesPolymorphic light eruption [1]
Polymorphic Light Eruption on the chest.jpg
PLE at V-neck/front of chest [2]
Specialty Dermatology   OOjs UI icon edit-ltr-progressive.svg
Symptoms Itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs [1]
Usual onsetShortly after sun exposure in people younger than age 30-years [3]
DurationSeveral days with annual recurrence [3]
CausesIncompletely understood
Prevention
  • Sun protection (SPF 50+) [3]
  • Cover up with densely woven clothing [2]
Treatment
  • Gradual sun exposure (hardening) [2]
Medication
FrequencyYearly (spring/summer), females>males [3]

Polymorphous light eruption (PLE) presents with itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs. [1] It generally appears 30 minutes to a few hours after sun exposure and may last between one and 14 days. [3] The bumps may become small blisters or plaques and may appear bloody, [3] often healing with minimal scarring. [3]

Contents

It is a non-life-threatening and potentially distressing [4] skin condition that is triggered by sunlight and artificial UV exposure [5] in a genetically susceptible person, [6] particularly in temperate climates during the spring and early summer. [2] Due to its many clinical appearances, it is named polymorphic or polymorphous and the terms are used interchangeably. [7] The resulting itch can cause significant suffering. [4] [8]

PLE is also defined as an idiopathic primary photodermatosis, [9] in which the photosensitizer is unknown. [4]

Treatments include prevention with sun avoidance and supervised light therapy, and symptom control with topical steroids. [4]

Signs and symptoms

Polymorphous light eruptions on the face of a 6-year-old girl, with scarring from past eruptions Sequeira Plate 6.jpg
Polymorphous light eruptions on the face of a 6-year-old girl, with scarring from past eruptions

Typically, the first episode develops in the spring following the first exposure to intense sun. [10] Further episodes of the irritable rash occur several hours to days following subsequent sun exposure. [11]

PLE appears on areas of the skin newly exposed to sunlight such as the visible part of the neckline, backs of hands, arms and legs, and feet, but less commonly the face. [2] [6] At these areas, there may be feelings of burning [9] and severe itching. Smooth red-topped small papules which merge into plaques, small fluid-filled blisters (papulovesicles) [2] and less commonly target-shaped lesions which look like erythema multiforme may be visible. [5] In addition, it may occur in other parts of the body in some people treated for inflammatory skin diseases with phototherapy. [2]

The rash is usually quite symmetrical and characteristic for each individual, appearing similar with each recurrence, but can look dissimilar in different people. [10]

Fever, fatigue and headaches have been previously associated with the eruption, but are rare. [2]

The rash may persist for many days to a couple of weeks, [5] resolving spontaneously without scarring as long as further sunlight exposure is avoided. [2]

Recurring yearly, the eruption can sometimes last longer than a few days if persistent and repeated sun exposure occurs. [2] However, the "hardening" effect, with respite during the later summer, frequently occurs with gradual exposure of sunlight, [5] eventually leading to significant improvement. [2]

Causes

The cause of PLE is not yet understood, but several factors may be involved. [6] It is thought to be due to a type IV delayed-type hypersensitivity to an allergen produced in the body following sunlight exposure, [12] in a genetically susceptible person. [10] It is also thought that skin microbiome or microbial elements could be involved in pathogenesis of the disease [13] [14]

UV exposure

PLE can be provoked by UVA or UVB (chief cause of sunburn) rays, meaning it can be triggered even by sunlight through glass. UV-A is a major constituent of sunlight, can pass through glass, is relatively resistant to sunscreen and can cause light eruption without sunburn. [2]

Artificial UV light sources from tanning units and phototherapy treatment units can also trigger PLE. About three-quarters of patients acquire PLE after UV-A exposure only, one-tenth after UV-B exposure only, and the rest after a combination of UV-A and UV-B exposure. [6]

People vary in the amount of sun exposure needed to trigger the rash. [15]

Oxidative stress

Oxidative stress and the modification of the redox status of the skin has been implicated in the expression of PLE. [6]

Photosensitizer

It has been suggested that an undefined endogenous or exogenous photo-allergen may trigger a delayed immune reaction resulting in PLE. [6]

Genetics

Half of patients have a family history of PLE, [6] demonstrating a clear genetic influence. [16]

Oestrogen effect

The preponderance in women with a decline in severity following menopause has been thought to be associated with oestrogen effects, [6] A natural fall in oestrogens may account for the tendency to remit after the menopause. [9]

Diagnosis

The diagnosis of PLE is typically made by assessing the history and clinical observations. Any investigations are usually to exclude other conditions, particularly lupus and porphyria. [9]

Blood tests are usually normal. However, positive antinuclear antibody and extractable nuclear antigen (anti-Ro/La) in low titre may be found, even in the absence of other criteria to suggest a diagnosis of lupus erythematosus. If clinical findings suggest a possibility of porphyria, urinary and red cell porphyrin screening may be performed and are negative in PLE. [2]

Photoprovocation tests are usually not required but may be undertaken by specialised centres in winter. [2] When a decision to undertake this is made, a small area of the frequently affected skin is exposed to varying doses of UVA and minimal erythema dose (MED) (amount of UV radiation that will produce minimal redness of skin within a few hours following exposure) [2] [17] of broadband UVB for three consecutive days. An examination of the skin to detect the rash is made, however, up to 40% have false negative responses. [2]

Biopsy findings

Depending on the clinical signs, histology of a skin biopsy may vary. There may be oedema in the epidermis with a dense superficial and deep lymphocytic infiltrate [10] without vasculitis. Recently appearing lesions may show neutrophils. Spongiosis and vesicle formation may also be present. Direct immunofluorescence testing is negative. [2]

Differential diagnosis

The photosensitivity connected with lupus erythematosus is the main condition that may appear like PLE. However, the rash of lupus is inclined to be more persistent. [2] PLE does not increase the risk of lupus. [15]

Other similar appearing conditions are solar urticaria, which has a shorter duration, the eczema-like condition, photosensitive dermatitis, [2] and photosensitivity drug reaction. [9]

Prickly heat, which is caused by warm weather or heat is not the same as PLE. [5]

Photosensitivity is also found in some of the porphyrias. Nearly all cases of porphyria cutanea tarda [18] exhibit blister formation on the skin within 2–4 days of light exposure. Variegate porphyria [19] and hereditary coproporphyria [20] can also exhibit symptoms of light-induced blisters. [18]

Classification

Sunlight has been documented to trigger numerous skin conditions and the confusing terminology and categorisation previously has made the correct diagnosis and subsequent treatment difficult. [4]

Variants of PLE have been described: [21] [12]

Treatment

Management entails regulating triggers whilst simultaneously inducing "hardening"; that is, steadily increasing exposure to sunlight, [2] as light sensitivity is reduced with repeated sun exposure [15]

Covering up with densely woven clothing has also been shown to help, in addition to applying a broad-spectrum, water-resistant semi-opaque sun protection factor (SPF) 50+ sunblock cream before sun exposure and then every two hours thereafter confers some protection. [2]

The application of topical corticosteroids may lessen the redness and itch, [2] and for preventing predictable holiday flare-ups, short courses of oral corticosteroids are sometimes considered. [2]

Another treatment option is a supervised course of low dose phototherapy, usually undertaken in winter. [2] If resistant, the administration of hydroxychloroquine in early spring is sometimes considered. [10]

As sun exposure is avoided, vitamin D levels may fall and hence supplements are sometimes advised. [22]

Prognosis

Generally, PLE resolves without treatment; also, PLE irritations generally leave no scar. [15]

There may be a possible link with autoimmune thyroid disease. [9] Some progression to autoimmune disease has been observed. [23] However, another study of people with elevated titres of antinuclear antibodies with PLE found no progression to lupus erythematosus after an 8-year follow-up. [16]

Epidemiology

In the United States, whilst one-quarter of people being investigated for a photosensitivity disorder were diagnosed with PLE, the prevalence in the general population is 10 to 15% and may even be as high as 40% as suggested in one study of more than 2000 people. [5] [6] It is also particularly more prevalent in Central Europe and Scandinavia. [4]

PLE is more common in young adults and has a female preponderance [5] with a ratio of 2:1 female-to-male. In Germany the female to male ratio has been cited as 9:1. [4] It can, however, occur in all age groups and all skin types. [6]

Those experiencing sun exposure all year round seldom acquire PLE eruption. [15] Hence, it is less common near the equator. [16]

The cases of this condition are most common between the spring and autumn months in the northern hemisphere and at higher altitudes. [12]

Society and culture

Reports of psychological distress have been made in more than 40% of peoples with PLE. [16] This includes emotional distress, anxiety and depression [12]

History

Thomas Bateman, following on from findings of his predecessor, Robert Willan, [24] first recorded a description of PLE in the nineteenth century, defining it as eczema solare with recurrent non scarring eczematous lesions triggered by sun exposure. [25] [26]

Danish physician Carl Rasch first described the eczema-like polymorphic light eruption in 1900, following his interest in the effect of sunlight on the skin. He has since been credited with coining the term "polymorphic light eruption". [27] [28]

See also

Related Research Articles

<span class="mw-page-title-main">Porphyria cutanea tarda</span> Medical condition

Porphyria cutanea tarda is the most common subtype of porphyria. The disease is named because it is a porphyria that often presents with skin manifestations later in life. The disorder results from low levels of the enzyme responsible for the fifth step in heme production. Heme is a vital molecule for all of the body's organs. It is a component of hemoglobin, the molecule that carries oxygen in the blood.

<span class="mw-page-title-main">Erythropoietic protoporphyria</span> Medical condition

Erythropoietic protoporphyria is a form of porphyria, which varies in severity and can be very painful. It arises from a deficiency in the enzyme ferrochelatase, leading to abnormally high levels of protoporphyrin in the red blood cells (erythrocytes), plasma, skin, and liver. The severity varies significantly from individual to individual.

<span class="mw-page-title-main">Contact dermatitis</span> Human disease

Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes are not contagious or life-threatening, but can be very uncomfortable.

<span class="mw-page-title-main">Gunther disease</span> Medical condition

Gunther disease is a congenital form of erythropoietic porphyria. The word porphyria originated from the Greek word porphura. Porphura actually means "purple pigment", which, in suggestion, the color that the body fluid changes when a person has Gunther's disease. It is a rare, autosomal recessive metabolic disorder affecting heme, caused by deficiency of the enzyme uroporphyrinogen cosynthetase. It is extremely rare, with a prevalence estimated at 1 in 1,000,000 or less. There have been times that prior to birth of a fetus, Gunther's disease has been shown to lead to anemia. In milder cases patients have not presented any symptoms until they have reached adulthood. In Gunther's disease, porphyrins are accumulated in the teeth and bones and an increased amount are seen in the plasma, bone marrow, feces, red blood cells, and urine.

<span class="mw-page-title-main">Pityriasis rosea</span> Skin disease

Pityriasis rosea is a type of skin rash. Classically, it begins with a single red and slightly scaly area known as a "herald patch". This is then followed, days to weeks later, by an eruption of many smaller scaly spots; pinkish with a red edge in people with light skin and greyish in darker skin. About 20% of cases show atypical deviations from this pattern. It usually lasts less than three months and goes away without treatment. Sometimes malaise or a fever may occur before the start of the rash or itchiness, but often there are few other symptoms.

<span class="mw-page-title-main">Mycosis fungoides</span> Most common form of cutaneous T-cell lymphoma

Mycosis fungoides, also known as Alibert-Bazin syndrome or granuloma fungoides, is the most common form of cutaneous T-cell lymphoma. It generally affects the skin, but may progress internally over time. Symptoms include rash, tumors, skin lesions, and itchy skin.

PUVA is an ultraviolet light therapy treatment for skin diseases: vitiligo, eczema, psoriasis, graft-versus-host disease, mycosis fungoides, large plaque parapsoriasis, and cutaneous T-cell lymphoma, using the sensitizing effects of the drug psoralen. The psoralen is applied or taken orally to sensitize the skin, then the skin is exposed to UVA.

Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include:

Photodermatoses is a skin condition resulting in abnormal skin reactions to ultraviolet (UV) radiation. These abnormal skin reactions may develop into rashes. While reactions to UV radiation is common, true photodermatoses is considered when an abnormal reaction is caused by UV-A rays or radiation between 320–400 nm.

<span class="mw-page-title-main">Transient acantholytic dermatosis</span> Medical condition

Grover's disease (GD) is a polymorphic, pruritic, papulovesicular dermatosis characterized histologically by acantholysis with or without dyskeratosis. Once confirmed, most cases of Grover's disease last six to twelve months, which is why it was originally called "transient". However it may last much longer. Nevertheless, it is not to be confused with relapsing linear acantholytic dermatosis.

<span class="mw-page-title-main">Solar urticaria</span> Medical condition

Solar urticaria (SU) is a rare condition in which exposure to ultraviolet or UV radiation, or sometimes even visible light, induces a case of urticaria or hives that can appear in both covered and uncovered areas of the skin. It is classified as a type of physical urticaria. The classification of disease types is somewhat controversial. One classification system distinguished various types of SU based on the wavelength of the radiation that causes the breakout; another classification system is based on the type of allergen that initiates a breakout.

<span class="mw-page-title-main">Lupus erythematosus</span> Human disease

Lupus erythematosus is a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues. Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs. The most common and most severe form is systemic lupus erythematosus.

Chronic actinic dermatitis is a condition where a subject's skin becomes inflamed due to a reaction to sunlight or artificial light. Patients often have other related conditions of the skin that cause dermatitis in response to a variety of stimuli.

<span class="mw-page-title-main">Drug eruption</span> Medical condition

In medicine, a drug eruption is an adverse drug reaction of the skin. Most drug-induced cutaneous reactions are mild and disappear when the offending drug is withdrawn. These are called "simple" drug eruptions. However, more serious drug eruptions may be associated with organ injury such as liver or kidney damage and are categorized as "complex". Drugs can also cause hair and nail changes, affect the mucous membranes, or cause itching without outward skin changes.

Actinic prurigo is a rare sunlight-induced, pruritic, papular, or nodular skin eruption. Some medical experts use the term actinic prurigo to denote a rare photodermatosis that develops in childhood and is chronic and persistent; this rare photodermatosis, associated with the human leukocyte antigen HLA-DR4, is often called "Familial polymorphous light eruption of American Indians" or "Hereditary polymorphous light eruption of American Indians" but some experts consider it to be a variant of the syndrome known as polymorphous light eruption (PMLE). Some experts use the term actinic prurigo for Hutchinson's summer prurigo and several other photodermatoses that might, or might not, be distinct clinical entities.

<span class="mw-page-title-main">Pseudoporphyria</span> Medical condition

Pseudoporphyria is a bullous photosensitivity that clinically and histologically mimics porphyria cutanea tarda. The difference is that no abnormalities in urine or serum porphyrin is noted on laboratories. Pseudoporphyria has been reported in patients with chronic kidney failure treated with hemodialysis and in those with excessive exposure to ultraviolet A (UV-A) by tanning beds.

<span class="mw-page-title-main">Sunburn</span> Burning of the skin by the suns radiation

Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, usually from the Sun. Common symptoms in humans and other animals include red or reddish skin that is hot to the touch or painful, general fatigue, and mild dizziness. Other symptoms include blistering, peeling skin, swelling, itching, and nausea. Excessive UV radiation is the leading cause of (primarily) non-malignant skin tumors, which in extreme cases can be life-threatening. Sunburn is an inflammatory response in the tissue triggered by direct DNA damage by UV radiation. When the cells' DNA is overly damaged by UV radiation, type I cell-death is triggered and the tissue is replaced.

Acne aestivalis also called as acne mallorca, is a special kind of polymorphous light eruption induced by ultra violet A radiation. This condition is said to be seasonal, usually affecting people in springtime and goes away in autumn when there is less sun light. This photo induced skin reaction leads to a mono-morphous eruption that consists of multiple, uniform, red, papular lesions. This skin reaction is classified as a delayed-type hypersensitivity because the onset is 24–72 hours after sun exposure. The condition equally affects men and women between the ages of 20–40 years old with no prior history of acne vulgaris. The eruption is unusual because it spares the face but it affects the lateral aspects of the upper arms, shoulder girdle, back, and chest. This condition's pathogenesis is not very well understood but scientists believe it an unfortunate side effect that results from a strong immune response to potentially cancer-causing cell damage.

Senile pruritus is one of the most common conditions in the elderly or people over 65 years of age with an emerging itch that may be accompanied with changes in temperature and textural characteristics. In the elderly, xerosis, is the most common cause for an itch due to the degradation of the skin barrier over time. However, the cause of senile pruritus is not clearly known. Diagnosis is based on an elimination criteria during a full body examination that can be done by either a dermatologist or non-dermatologist physician.

Acute cutaneous lupus erythematosus is a cutaneous condition characterized by a bilateral malar rash and lesions that tend to be transient, and that follow sun exposure. The acute form is distinct from chronic and subacute cutaneous lupus erythematosus, which may have different types of skin lesions. Cutaneous lupus erythematosus is associated with both lupus erythematosus-specific lesions and cutaneous manifestations that are not specific to lupus erythematosus, such as oral ulcers and urticaria. Because of the diagnostic criteria used to diagnose systemic lupus erythematosus, a patient with only cutaneous manifestations may be diagnosed with the systemic form of the disease.

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