I've had awful hayfever for about 15yrs now. Before I became pregnant, I used a beconase inhaler, eye drops, benadryl 3-a-day tablets, citirizine tablets and an asthma inhaler (the doc said i'd be ok to combine the tablets occasionally...)
The combo worked really well, but I couldn't take ANYTHING when pregnant... so I went all out and bought a homeopathy kit. Its really good. There were about 12 different remedies in the kit, and a sheet explaining the symptoms to look out for for each remedy. Itchy mouth is my worst symptom, and a general lethargy, heavy / tired body and achey head. Arundo remedy worked wonders for me (symptom description: Itching in nostrils & sneezing; Itching in roof of mouth and ears) and gelsemium (symptom: Where there is voilent sneexing and the nose tingles and streams, partic in the morning. Face feels hot, eyes heavy, throat and swallowing causes pain in ears. Body aches and limbs feel heavy).
I'm still breastfeeding, so I still can't take most of my old prescriptions, and the homeopathy is great as a 'boost'. You can buy mail order online from some places. It doesn't always work, but i think thats because its sometimes v hard to diagnose yourself when you're feeling really awful!!
hope you find something that helps, its really terrible, and last weekend was a nightmare. i itched the back of my mouth with my tongue so hard at the weekend, that I've got a massive painful ulcer beside my tonsils now, and its not going away!!!
xx