Standard Article


Target Organ and Tissue Toxicity

  1. Rūta Dubakienė Dr. Med. Habil

Published Online: 15 DEC 2009

DOI: 10.1002/9780470744307.gat178

General, Applied and Systems Toxicology

General, Applied and Systems Toxicology

How to Cite

Dubakienė, R. 2009. Photoallergy. General, Applied and Systems Toxicology. .

Author Information

  1. Vilnius University, Professor, Clinics of Chest, Allergology and Radiology, Medical Faculty, Vilnius, Lithuania

Publication History

  1. Published Online: 15 DEC 2009


Photosensitive skin reactions occur when human skin abnormally reacts to ultraviolet radiation or visible light. The forms of photosensitivity are phototoxity and photoallergy. Phototoxic disorders have a high incidence, whereas photoallergic reactions are much less frequent in the human population. Several hundred substances, chemicals or drugs may invoke phototoxic or photoallergic reactions. In order to avoid photosensitive reactions it is essential to determine the photosensitizing properties of such substances before drugs are introduced in therapy or products made available on the market. This chapter reviews the mechanisms of photosensitization, explains the most important differences between phototoxic and photoallergic reactions, summarizes the most common photosensitzers and presents the clinical features and diagnostic procedures of phototoxic and photoallergic reactions.


  • photosensitivity;
  • photosensitizers;
  • phototoxic reaction;
  • photoallergic reaction