My father has had swelling of serosanguinous fluid (that clear/red tinged fluid). It is important to note that the fluid has NO PUS, no white, green or any other color fluid. He gets these places on his face and back. They don't have a head - you wouldn't know they were there except his cheeks look big - he has to cut them open to relieve the pain from the swelling. He loses so much blood when he opens them that he has had to have 2 blood transfusions. However, 'bleeding' them is the only way he can get relief. Other symptoms include fever, severe skin sensitivity (all over his body - not just where the items are swollen), and fatigue (probably from the blood loss). He thinks that the swollen areas are always present, but just not always swollen to the point of hurting. They seem to be exacerbated by heat, humidity, and stress. He has been to many doctors and none know what it is. The last one sent him to a psychiatrist who said he needed to see a doctor.
I hope someone out there recognizes this disorder. He is miserable and I really want to help him.