[Why is my foot swollen and red?].

We present the case of a 26 year old man reporting to the family doctor due to swelling and redness of the foot. After thrombosis and a tumorous mass could be excluded, the suspicion fell on an acrodermatitis chronica atrophican which could be confirmed by laboratory tests. During therapy there was a significant regression of the cutaneous lesion. The treatment of the Lyme disease was taken over by the casualty insurer.