Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042109 (urticaria)
 6,569 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The acute idiopathic photodermatoses are more common in females and comprise polymorphic light eruption, actinic prurigo, hydroa vacciniforme, and solar urticaria. Polymorphic light eruption occurs considerably more frequently than the others and while precise pathogenic mechanisms are still unclear, increasing evidence suggests an immunological basis for this condition. Although clinically distinct, actinic prurigo may be a variant of polymorphic light eruption, whereas solar urticaria and possibly hydroa vacciniforme are distinct entities, the former representing a type I hypersensitivity response. Polymorphic light eruption is characterized by a recurrent cutaneous reaction to ultraviolet (UV) exposure occurring after a delay of several hours that consists of pruritic erythematous papules, vesicles, or plaques on usually only some exposed sites and resolves without scarring over about a week. Actinic prurigo is differentiated from polymorphic light eruption by childhood onset and more persistent and excoriated lesions present both on sun-exposed and, to a lesser extent, non-exposed sites. Hydroa vacciniform is a rare disorder that also begins in childhood, and is characterized by recurrent crops of vesicles on sun-exposed skin and subsequent vacciniforme scarring. Solar urticaria is an uncommon condition that usually begins in the third or fourth decade and is differentiated from the other acute idiopathic photodermatoses by rapid onset of urticarial lesions within minutes of UV exposure and resolution within 1 to 2 hours.
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PMID:The acute idiopathic photodermatoses. 220 41

Polymorphous light eruption (PLE) is a common photodermatosis of unknown etiology. It afflicts mainly fair-skinned patients, with a preponderance of young females. There is, however, no absolute restriction as to age, sex, or race. Clinical variants include the papular, vesiculo-bullous, and hemorrhagic variety, as well as plaque, erythema multiforme-like, and insect bite (strophulus)-like types. Skin lesions appear only in certain exposed areas hours or a few days after intense sunshine, and are nearly always monomorphous in the same patient. The rash subsides spontaneously within several days without leaving scars. The histopathologic picture is characteristic and shows a perivascular lymphocytic infiltrate in the upper and middle corium with subepidermal edema, vacuolization of basal cells, and spongiosis in the lower epidermis. The most important differential diagnoses are solar urticaria, photosensitive erythema multiforme, and lupus erythematosus. The action spectrum of PLE is under debate. Reproduction of skin lesions has been reported with UVB, UVA, and, rarely, visible light, with UVA probably being the most effective part of the spectrum. More important than treatment of PLE is prophylaxis. UVA- and UVB-effective sunscreens are of some help. Phototherapy and especially photochemotherapy (psoralen + UVA; PUVA) offer effective ways to decrease light sensitivity. Systemic treatment with chloroquine or beta-carotene has been disappointing.
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PMID:Polymorphous light eruption. 381 73

Polymorphous light eruption (PLE) and solar urticaria (SU) are two photodermatoses that are induced by ultraviolet radiation and sometimes by visible light. This article will review the various means of preventing PLE and SU with an emphasis on the role of sunscreens.
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PMID:Prevention of polymorphous light eruption and solar urticaria. 1243 26

Photoallergic dermatoses are skin lesions following sun exposure, characterized by activation of immunological mechanisms, involving photosensitizers and photoallergens that can cause photosensibilization in some individuals. In this group of disorders, photoallergic contact dermatitis should be accentuated. It manifests as contact allergic dermatitis on sun-exposed skin areas, following direct contact with photoallergens during UV exposure (predominantly UVA). Under influence of light, photosensitizers get activated, followed by fusion with cutaneous proteins which renders them to complete antigens, and consequential initiation of immunological mechanisms with resulting pathological skin lesions. The most common photoallergens are: sulfonamide antibiotics, phenothiazines, and halogenated salicylanilides. Photoallergic dermatoses are comprised of several disorders, although the causative photoallergen remains unknown (e.g. solar urticaria, polymorphous light eruption and hydroa vacciniforme). Solar urticaria is a rare, acute urticarial reaction on both sun-exposed and covered skin areas, which appears soon after exposure to sun or artificial lighting. Polymorphous light eruption is a relatively common polymorphous skin eruption, which usually appears in spring. Its pathogenesis is unknown, presumably photoallergic reaction. Hydroa vacciniforme is a rare photodermatosis of unknown etiology, which usually presents in summer-time. It is characterized by vesicobullous eruptions, with residual nonesthetic varioliform scarring.
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PMID:Allergic hypersensitivity skin reactions following sun exposure. 1913 19

Electromagnetic radiation may cause distinct skin conditions. The immunologically mediated photodermatoses (IMP, previous term: idiopathic photodermatoses) represent a heterogenous group of disorders presenting with pathologic skin reactions caused by optical radiation, particularly in the UVA wavelength region. The exact pathomechanism in IMP remains to be elucidated; however, it is very likely (auto)-immunologic in nature. Polymorphic light eruption, actinic prurigo, hydroa vacciniforme, chronic actinic dermatitis, and solar urticaria are the most important conditions that may be summarized under the term IMP. IMP frequently result in a significant reduction in quality of life in affected individuals, mainly because of troublesome symptoms such as intractable itch and pain. Photodiagnostic procedures are mandatory for the exact determination of action spectra and the degree of photosensitivity. Broad-spectrum photoprotection is essential in the prevention of IMP. Photo(chemo)therapeutic regimens are predominantly used to increase the cutaneous immunologic tolerance against ambient UV radiation. In severe forms of IMP, immunomodulatory and immunosuppressive therapies may need to be considered. Overall, IMP form a significant group of skin conditions that can be extremely disabling to the patient and are difficult to diagnose and treat.
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PMID:Immunologically mediated photodermatoses: diagnosis and treatment. 1935 31

Photodermatoses are a group of skin disorders caused or exacerbated by ultraviolet and/or visible radiation, which collectively affect a high proportion of the population and substantially affect quality of life (QoL). Our objective was to assess the psychological impact of these conditions. Patients with a range of photodermatoses diagnosed at a specialist investigation centre in the UK completed questionnaires evaluating (i) anxiety and (ii) depression, using the Hospital Anxiety and Depression Scale (HADS), (iii) social anxiety, using the Fear of Negative Evaluation measure (FNE), (iv) coping strategies (brief COPE) and (v) QoL, using the Dermatology Life Quality Index (DLQI). Questionnaires were returned by 185 of 260 patients (71.1% response rate). Mean age was 50.2 years (SD 14.5, range 20-85), 80.3% female. Polymorphic light eruption was the most common diagnosis, followed by photoaggravated eczema, other photoaggravated dermatological conditions and solar urticaria. Across the sample, high percentages, i.e. 23% and 7.9% of individuals, showed scores indicating clinical levels of anxiety and depression, respectively. Facial involvement was a strong indicator for depression (t = 2.7, p < 0.01). In regression analyses psychological factors (particularly depression and adaptive coping) were the principle predictors of QoL, accounting for 17.7% of the variance (F = 7.61, p < 0.01), while clinical variables accounted for an additional 10.1% (F = 8.96, p < 0.01), with number of months/year affected exerting a significant effect (p < 0.01). This study demonstrates the high psychological comorbidity of these conditions; more awareness of this is required, with adoption of a biopsychosocial approach to their management.
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PMID:Photodermatoses: environmentally induced conditions with high psychological impact. 2296 5

Photodermatoses are a group of skin diseases primarily caused by, or exacerbated by exposure to ultraviolet and or visible radiation. The effect of sunlight on skin depends on a number of factors including skin colour, skin phototype and the content and type of melanin in the skin. There are only a few studies describing photodermatoses in populations with dark skin. A PubMed search was conducted to summarize currently available information on differences in biology of melanin in dark and light skin and photodermatoses in dark skin. Dark skin is characterised by higher content of melanin, higher eumelanin to pheomelanin ratio, lower tyrosinase activity, and more effective distribution of melanin for protection against ultraviolet light. Photodermatoses are common in dark skinned patients with some variation in the spectrum of photodermatoses. Polymorphous light eruption (PMLE) is the commonest, followed by chronic actinic dermatitis. Pin-point papular and lichenoid variants of PMLE and actinic lichen planus are more frequent in dark skin whereas actinic prurigo, solar urticaria and hydroa vacciniforme are uncommon. Photodermatoses are common in dark skinned patients despite better natural photoprotection. It is proposed that lichenoid photodermatoses may be added to the classification of photodermatoses in dark skin.
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PMID:Photodermatoses in pigmented skin. 2312 22

The systematic evaluation of photosensitive patients involves a comprehensive history, physical examination, phototesting, and, if necessary, photopatch testing and laboratory evaluation. Polymorphous light eruption, chronic actinic dermatitis, solar urticaria, and photosensitivity secondary to systemic medications are the most commonly encountered photodermatoses in dermatology clinics worldwide.
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PMID:Evaluation of patients with photodermatoses. 2489 Oct 50