Outline 3.1 Introduction 3.2 Signs and Symptoms 3.3 Description of the Skin Lesions 3.31 Gross Appearance 3.32 Microscopic Appearance 3.33 Epilation and Nail Pigmentation 3.4 Therapy 3.5 Factors Influencing Severity of the Lesions 3.51 Character of the Fallout Material 3.52 Dose to the Skin 3.53 Protective Factors 3.54 Factors Favoring the Development of Lesions 3.6 Lack of Correlation With Hematological Findings 3.7 Discussion 3.8 Summary