Phototherapeutic and photosensitive agents

Abstract:

Topical photoactive drugs of plant origin administered in combination with sun exposure may be effective treatment for different skin disorders. The most important phototherapeutic methods are photochemotherapy (PUVA) and photodynamic therapy (PDT). PUVA includes the use of a photosensitising agent in combination with UVA light (ultraviolet light with a wavelength between 320 and 400 nm). It is indicated in the treatment of severe forms of psoriasis and atopic dermatitis. PTD involves the use of photochemical reactions mediated by interactions between photosensitizing agent, visible light and oxygen in the affected tissue. It selectively destroys premalignant and malignant cells and preserves the healthy tissue. Special attention should be given to drug-induced photosensitivity, whose manifestations include phototoxic, photoallergic or lichenoid reactions, subacute cutaneous lupus erythematosus or porphiria. Drug-induced photosensitivity may be caused by many different drugs used in everyday practice. 

Key words:
dermatitis, photoallergic; dermatitis, phototoxic; photochemotherapy; ultraviolet rays