My father has had a skin allergy since the beginning of May - red blotches on the lower arms and back, which have spread to larger areas across the lower back and lower arms. The arms have become much worse all underneath the lower arm is red and itchy and it has now become swollen in the last week since he has been given anti-histamines. He is on warfarin and has had small eczema patches but I believe this is hives as it is red, slightly raised, hot and itchy. The muscles under the chin area are also swollen and the side of the face is itchy and slightly red and slightly swollen.