swelling on hands

I have red hot swollen areas on my hands. these always appear overnight. the swelling can be 2 - 3 in in diameter, which is pretty large. the swelling is also very prominent.
I cleaned my bed and bed linens. also cleaned the area around the bed.
the swelling takes 3-5 days to disappear. at the end it gets very itchy. sometimes i notice a red spot at the center, like something bit me, but most times there is no sign of a bite. Once i had multiple of these everyday. so i took allegra and they went away. this was almost 1.5 years ago. now again i have these. i cant think of a reason why i get these. my husband sleeps on the same bed, but he has no such symptoms. its only me.
i really want to find a prevention to this problem please help

[Dr Santos]

Hi,
How are you? Are there other symptoms present? It is good that the swelling resolves after intake of antihistamine, which suggests that it is due to histamine release similar to allergies.  management is usually with avoidance of triggers.  A journal to identify the possible triggers for every recurrence may help. If the trigger can not be identified, an allergy test may help. Check with your doctor or be referred to a dermatologist for proper evaluation. Take care and hope to hear from you soon.  

[Stephanie1013]

Hi Suma,

I have had the same problem for the past 2 years. My symptoms started with instant itching and swelling. I went to an allergist and she did a skin test on me. It came back that I am allergic to everything on earth BUT (oranges and seasame seeds) how can that be possible? I have since been taking an allergy pill everyday for 2 years. It seems to work when the symptoms begin. Yesterday my hand swelled up and an allergy pills did not take the swelling down. My sugestion to you would be to go to a doctor and don't leave untill you get an answer to resolve your problem. If you do get an answer please let me know. Best of luck to you,

Steph