Q: I am 40 years old and all of a sudden I develop hives on my left cheek, which leads to itching. The left part of my face then starts to swell and my head starts hurting. I took Benadryl (diphenhydramine) but the swelling is still there. My head turns cold too. What is my problem?

A:You seem to be having a condition called angioedema. Angioedema is an uncomfortable and disfiguring type of temporary swelling and at worst a life-threatening one. It is very similar in many ways to urticaria, with which it often coexists and overlaps. Although both conditions may result from allergy, mostly this is not the case when they keep happening without apparent cause. The swellings happen especially in the lips and other parts of the mouth and throat, the eyelids, the genitals, and the hand and feet. If you get angioedema one or both of your lips may look like sausages, your eyelids may be nearly or even completely closed by swelling, or your tongue may be so swollen that you have difficulty speaking. Angioedema is life threatening if swelling in your mouth or throat makes it difficult for you to breathe. Less often the sheer amount of swelling means that so much fluid has moved out of your blood circulation that your blood pressure drops. Fortunately only a small minority of people with angioedema get these dangerous features, but if you are one of them you need detailed instruction by a specialist in the necessary safety precautions, and special care to make sure that some undiscovered cause of your trouble has not been overlooked. Angioedema is called acute if it lasts only a short time (minutes to days) and does not keep coming back. A typical example would be angioedema caused by eating shrimps or prawns if you are allergic to them. However, acute angioedema can also be caused by the same things, which cause chronic angioedema. If angioedema keeps coming back over a long period, it is called chronic angioedema. If one is hypersensitive to aspirin, or some other drugs, one may get swelling which can sometimes be life-threatening, not only from aspirin, but also from other painkillers such as ibuprofen and other drugs of a type also used for rheumatic conditions. The treatment of angioedema is in many ways very similar to the treatment for urticaria. You may need adrenaline (epinephrine) inhalers or injections if you have swelling in your mouth or throat, so that you have difficulty in breathing or if this seems a danger. In the rare form of angioedema caused by lack of C1 inhibitor, Adrenaline seems not to help particularly and antihistamines are of no use, though people still try adrenaline; other treatments are more important in C1 inhibitor deficiency. Avoid the cause if you or your doctor can find one. Allergy to nuts, latex, other foods, and medicines can all cause angioedema. Avoiding medicines, which cause angioedema in ways other than allergy may solve your problem. Aspirin hypersensitivity for example is not a true allergy, but is important and means you also have to avoid some other medicines and may have to avoid some foods. Antihistamines often help tremendously in preventing swellings, and it may be worth your while to take one regularly. Make sure you get one with no unnecessary side effects. If you take them by mouth it takes about an hour before they get into your bloodstream. But in some people antihistamines don't help the angioedema at all. This is very frustrating. Sometimes when this happens tablets used for hereditary angioedema (tranexamic acid and epsilon-aminocaproic acid) help when antihistamines have failed. We don't know the reason for this, but we are grateful when it works. If you feel an attack of swelling is not under good control, or might slip out of control, get yourself to a hospital with emergency facilities.