An allergy can often be somewhat of a mystery, starting off with a stuffy nose and swollen eyes, ending in itchy, irritated skin or exacerbated asthma symptoms. Whichever side effects your allergy is causing it's best to find out what that allergy is and eradicate what's causing it.
Finding out what you're allergic to is easier said than done, so be prepared to do some painstaking research. If your symptoms have come on suddenly then think of what has changed in your home or work environment. Has someone bought a new pot plant to the office? Is it that time of year when everything starts to release pollen? Perhaps you've recently changed make up and your skin is reacting to it. It could even be a change in diet. Unfortunately, allergies can develop as we grow older, so something you weren't allergic to as a child could be causing you problems now. Similarly, things can trigger reactions, such as stress or illness, so if you've suffered from one of these bear in mind that it might not be a new allergen.
Firstly, keep a diary of your symptoms, when they start and when they are at their most severe (or when they're completely absent). Does caffeine make them worse? Are they worst when you first wake up and go to bed at night? This diary will be very useful to show your doctor, or it might identify trends that you can discuss with an allergy specialist.
If you think it could be something in your home, like dust mites, a pet allergy or new detergent causing the problem then try spending time in different rooms each day. If you find the allergies are worst on the days you spend in your bedroom and that's where the detergent is (on the bedclothes) then give the rest of the bottle away and buy some hypo allergenic detergent instead. Also, doing a very thorough hoover, in all the corners, shaking out rugs, cushions and dusting everywhere can help with dust mite allergies. If you find your symptoms are better after this then you may find that all you need to do is a very thorough clean one a fortnight.
One sure fire way to find out if you are allergic to certain foods, dust mites, dander from household pets or various chemicals is to order a home test from the internet. These can be expensive at around £19 per kit to test for one thing, but they're very useful if your doctor is reluctant to refer you to a specialist or you're almost sure it's this one substance causing the allergic symptoms.
If you have no idea what could be causing your allergic reaction then you will need the patience to try out things one at a time to see if they make your condition worse or better. Of course, at some point you may have to put up with worsened symptoms when you hit the jackpot. Just remember that after this revelation you can start work towards removing that allergen from your life and live itch, asthma and eczema free from then on.