Case report
Allergic Hypersensitivity Skin Reactions Following Sun Exposure
Liborija Lugović Mihić
Vedrana Bulat
Mirna Šitum
Vlatka Čavka
Iva Krolo
Abstract
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.
Keywords
allergic reactions; sun allergy; photoallergic reactions; solar urticaria; polymorpheus light eruption; photodermatoses
Hrčak ID:
34643
URI
Publication date:
1.10.2008.
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