>>Antihistamines ... will probably also make you sleepy...

There are some (e.g. loratadine, sold as Claritin) that do not pass the blood brain barrier. Interestingly, at least one of the ones that does pass the BBB can slow the progression of MS as it inhibits the auto-immune reaction that's destroying oligodendrocytes. Patients don't stay on it as is makes them soo... sleeepy...

Also, there's some correlational data showing that chronic use of first generation antihistamines raises the risk for dementia. Note that correlation is not causation - but I'd stick with the second generation ones.