In cellulitis which is a serious, bacterial skin
infection there is a skin
rash with areas of swollen red skin
that are hot and sensitive to the touch. Contact dermatitis, insect bite all can cause red itchy rash on the ankle but swelling is unlikely in these conditions. Ankle swelling can be seen in rheumatoid arthritis, reactive arthritis, osteoarthritis, gout.heart problems, kidney ailments etc. In gout the joint appears purple, shiny, feels very sore and tender, and is inflamed/swollen.