Change in medicine occurs all the time.This often imperceptible progress is ata much more rapid pace than weimagine. With these thoughts in mind Itackled the third edition of this book,asking myself, for every sentence andeach page, 'how has the practice andapproach to the topic been advanced?'Many changes, both subtle and moreblatant, were needed. Advances ingenetics, molecular biology andimmunology have been incorporated,alterations in treatment regimensinserted and the cultural change of'theh ...