Feeling the Burn: Phototoxicity and Photoallergy.

An interaction between light's radiation and certain exogenous and endogenous substances can lead to the development of photoallergic and/or phototoxic dermatoses. Clinically, reactions may range from acute and self-limited to chronic and recurrent. Delays in diagnosis are not uncommon due to complex clinical presentations, broad differentials, and limited number of specialists who perform phototesting. Therefore, a critical understanding of these dermatoses is essential for accurate diagnosis and appropriate management. The epidemiology, light sources, mechanisms, clinical presentations, evaluation protocols, common culprits, treatments, key challenges, and future directions related to photoallergy and phototoxicity are reviewed herein.

Photocontact Dermatitis and Its Clinical Mimics: an Overview for the Allergist.

Photo-contact dermatitis (PCD) describes the adverse cutaneous reaction that occurs in some patients as a result of simultaneous exposure to a contactant and to light. PCD can be subdivided into photo-allergic and photo-irritant dermatitis depending on whether the contactant respectively invokes an allergic or irritant reaction. Photo-irritant reactions are commonly caused by plants, psoralens, and medications taken internally, whereas photo-allergic reactions are commonly caused by sunscreens and topical nonsteroidal anti-inflammatory medications. The work-up of photo-contact dermatitis includes a thorough history and physical exam augmented by patch and/or photopatch testing, as the cornerstone of treatment for PCD is identification and avoidance of the irritating or allergenic chemical. Photo-contact dermatitis has the potential to significantly impact quality of life, so an informed approach to diagnosis and management is critical. Clinical mimics of PCD include polymorphic light eruption, solar urticaria, actinic prurigo, hydroa vacciniforme, cutaneous porphyrias, and systemic disorders with photosensitivity such as lupus and dermatomyositis. Herein, we review the clinical presentation, differential diagnosis (including the clinical mimics mentioned above), pathogenic mechanisms, diagnostic testing, and therapeutic considerations for PCD.

Allergic contact dermatitis: Patient management and education.

Allergic contact dermatitis is a common diagnosis resulting from exposure to a chemical or chemicals in a patient's personal care products, home, or work environment. Once patch testing has been performed, the education and management process begins. After the causative allergens have been identified, patient education is critical to the proper treatment and management of the patient. This must occur if the dermatitis is to resolve. Detailed education is imperative, and several resources are highlighted. Photoallergic contact dermatitis and occupational contact dermatitis are other considerations a clinician must keep in mind.

Analysis of solar urticaria in Thai patients.

BACKGROUND: Solar urticaria (SU) is an uncommon photodermatosis characterized by erythema and whealing within minutes to a few hours after exposure to sunlight or an artificial light source. OBJECTIVE: To determine the clinical features, photobiological characteristics and treatment outcomes in Thai SU patients visiting a tertiary referral hospital. METHOD: A retrospective analysis of 13 patients with SU was conducted. Demographic data, disease characters, phototesting results, laboratory investigations, treatment and outcome were evaluated. RESULTS: Of the 13 patients diagnosed with SU from 2000 to 2012, most patients were female (10, 77%). The mean age of onset was 29 years (15-51). The mean duration of SU was 46 months (6-120) at presentation. The most common affected location was the upper extremities (92%), followed by head and neck (77%). The responsible action spectra were visible light in 8 patients (61.5%), ultraviolet A (UVA) in 1 patient (8%), and both visible light and UVA in 4 patients (31%). The median course from disease onset to disease resolution was 63 months (95% confidence interval 30-95). After 13 months and 55 months from the onset of symptoms, 23% and 49% of patients, respectively, were predicted to recover from their symptoms. CONCLUSION: Solar urticaria is a rare condition in Thailand. The common eliciting spectra of SU were visible light and UVA. Management of SU remains challenging.

Photosensitive disorders of the skin with ocular involvement.

Patients with photosensitive disorders of the skin may present with ocular manifestations that are evident at birth or may be manifested later with progression of the disorder. Dermatologists should be able to recognize these and appropriately refer patients for further management. Ocular involvement associated with immunologically mediated photodermatoses, drug- and chemical-induced photosensitivity, photodermatoses associated with defective DNA repair/chromosome instability, and photoaggravated dermatoses are reviewed. Photodermatoses are commonly classified into four general groups: (1) immunologically mediated photodermatoses; (2) drug- and chemical-induced photosensitivity; (3) photodermatoses associated with defective DNA repair/chromosome instability; and (4) photoaggravated dermatoses. Photodermatoses in these groups with ocular involvement will be discussed. In addition, skin diseases associated with photophobia are also described.

Adverse reactions to sunscreen agents: epidemiology, responsible irritants and allergens, clinical characteristics, and management.

Sunscreen is a key component in the preventive measures recommended by dermatologists and public health campaigns aimed at reducing sunburn, early skin aging, and skin cancer. To maximize compliance, adverse reactions to sunscreens should be minimized. Although inactive ingredients cause many of these reactions, it is important for dermatologists to be aware of reactions to active ultraviolet filters. There are approximately 120 chemicals that can function as ultraviolet (UV) filters. This review focuses on the 36 most common filters in commercial and historical use. Of these, 16 are approved for use by the US Food and Drug Administration. The benzophenones and dibenzoylmethanes are the most commonly implicated UV filters causing allergic and photoallergic contact dermatitis (PACD) reactions; benzophenone-3 is the leading allergen and photoallergen within this class. When clinically indicated, patch and photopatch testing should be performed to common UV filters.

Fitofotodermatite por Ruta graveolens com manifestação cutânea extensa / Phytophotodermatitis due to Ruta graveolens with extensive cutaneous manifestation

Dermatite de contato por planta ou fitodermatite é uma erupção cutânea resultante do contato com substâncias produzidas por diferentes espécies de vegetais. Ruta graveolens, popularmente conhecida como arruda, é uma planta da família das Rutaceae, que inclui algumas frutas cítricas, e contém inúmeras substâncias químicas fotossensíveis, incluindo os furocumarínicos. Relatamos um caso de reação de fitofototoxicidade grave em uma paciente que usou uma infusão de arruda pelas supostas qualidades ”místicas e purificadoras” da planta com extensa erupção cutânea.

Plant dermatitis or phytodermatitis is a cutaneous eruption resulting from contact with substances produced by different plant species. Ruta graveolens, popular known as common rue, is an herbal plant from the Rutaceae family, which includes the citrus fruits, and contains numerous photosensitizing substances, including furocoumarins. We report a severe case of phytophototoxicity reaction in a patient who used a common rue infusion because of its “powerful and purification” qualities.

Photodermatoses: classification, evaluation and management.

Photodermatoses are skin disorders induced or exacerbated by light. They can be broadly classified into four groups: (i) immunologically mediated photodermatoses (idioapathic); (ii) drug- and chemical-induced photosensitivity; (iii) defective DNA repair disorders; and (iv) photoaggravated dermatoses. The exact pathomechanism of those diverse skin reactions to light radiation remains unclear. Immunologically mediated photodermatoses are the most common dermatoses among all photosesnsitive disorders. The management of photodermatoses starts with clinical recognition of characteristic lesions localized predominantly in light exposed skin. Detailed history-taking, phototesting and photopatch testing are required to establish a correct diagnosis, especially if patients present in disease-free intervals. Classification and short description of distinctive clinical features of most common photodermatoses, several practical aspects of evaluation and management of the patient with photosensitivity will be outlined.

Photodermatoses with onset in the elderly.

Photodermatoses are a group of skin disorders induced by ultraviolet radiation (UVR) and, in some cases, visible light. To establish a diagnosis it is important to carefully take a history, physical examination and perform phototesting as well as other testing when appropriate (patch and photopatch tests, antinuclear antibodies, porphyrin profile). This article focuses on the photodermatoses that affect the elderly, which with the ageing of population, particularly in the industrialized societies, are becoming an increasingly important group for the healthcare systems. The most common photodermatoses with onset in the elderly are chronic actinic dermatitis and drug induced photosensitivity.

Allergic hypersensitivity skin reactions following sun exposure.

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.

[Eczematous skin diseases]. / Ekzemás megbetegedések.

The skin, as one of the most important barriers of the human body, protects the inner homeostasis from the harmful environmental influences as well as physical, chemical and biological factors. When the impact of these factors exceeds the tolerance and reproducing capacity of the skin, pathological alterations will develop. If follows from this that dermatology can surely be considered to be a part of environmental medicine. Eczematous diseases are mostly pathological pictures of varied mechanisms developing as a result of environmental influences (irritants, contact allergens, microbes). Since their clinical appearance is similar, it is a serious professional challenge to diagnose them. In this article we present the clinical features, provoking factors of these skin diseases as well as therapeutical possibilities.

Investigation of photosensitive disorders.

Investigation of photodermatosis is based primarily on the history and clinical findings, histological, immunological and biochemical findings are variably helpful depending on the clinical picture. Formal testing for photosensitivity may be the only definitive test proving photosensitivity on occasion. This article delineates the important features which allow classification of patients which then enables appropriate treatment.

Photosensitivity to exogenous agents.

OBJECTIVE: To better understand cutaneous photosensitivity reactions, a review of its etiologic factors, clinical characteristics, pathogenesis, and treatment modalities was undertaken. METHODS: Articles discussing the above aspects of phototoxic and photoallergic reactions were used to demonstrate what is currently known about photoinduced reactions and how to treat them. RESULTS: Upon interaction of solar UV radiation with the chemical that is present in significant levels on the skin, one of two known reactions may occur in susceptible patients: a phototoxicity and/or photoallergy. Phototoxic and photoallergic reactions can be diagnosed separately on the basis of pathogenesis, clinical characteristics, and histology. Examples of drugs capable of inducing a phototoxic reaction include amiodarone, retinoids, nonsteroidal antiinflammatory agents, diuretics, and antibiotics. Substances known to cause a photoallergic response are fragrances, sunscreens, topical antimicrobials, NSAID, and psychiatric medications, such as chlorpromezine. CONCLUSION: Photoinduced reactions produced by exogenous chemicals are common skin disorders. Definitive therapy requires identifying and removing the offending agent, either the photosensitizing chemical or light. The use of fully protective clothing and a sunscreen of high SPF are important measures when light exposure is inevitable.

[Solar urticaria]. / Lichturtikaria.

Solar urticaria serves as a model to illustrate the photodiagnostic approach in rare photodermatoses and to demonstrate how patients can be effectively helped by prophylactic and therapeutic intervention. To accomplish these tasks, advanced knowledge and experience in photodermatology is required, along with equipment which is often available in specialized centers only. A list is attached listing the dermatology departments with photodiagnostic units in Germany, Austria, and Switzerland.

Clinical and therapeutic aspects of polymorphous light eruption.

BACKGROUND: Polymorphous light eruption (PLE) is an idiopathic eruption induced by ultraviolet (UV) radiation (UVR). OBJECTIVE: Evaluation of the clinical aspects, diagnostic criteria of PLE in a major Swiss referral center. METHODS: 25 patients with PLE were tested with a standardized protocol for the assessment of photodermatoses. RESULTS: 25 patients (22 women vs. 3 men) were identified. Papular and papular-vesicular eruptions were the most common clinical presentations. 6 of 25 patients had a reduced minimal erythema dose (MED) for UVA and 8 of 25 patients had a reduced MED for UVB. Photoprovocation was positive in 11 of 20 patients for UVA and 7 of 20 patients for UVB. Photohardening with narrow-band UVB was successful in 8 of 10 patients. Combined UVA/UVB therapy had a satisfactory effect in 10 of 15 patients. Narrow-band UVB therapy was still successful after ineffective UVA/UVB therapy. CONCLUSION: The MED was of no value for the diagnosis of PLE. The typical lesions were reproduced by UVA and UVB photoprovocation. We recommend photohardening with narrow-band UVB (311 nm).

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.