Specific immune therapy could work for many people with allergies, according to the German Institute for Quality and Efficiency in Health Care.
The Institute has reviewed the latest independent analyses of allergy research to find out which treatments or prevention measures could really work.
Allergen immunotherapy can be done by injections or sublingual drops, tablets or sprays. Both injections and sublingual treatments work.
A report has shown that more than a dozen of these immunotherapy extracts are now amongst the 3,000 most prescribed medicines in Germany.
"Sublingual therapy in particular is becoming very popular in Europe. Research has shown that it can reduce allergic symptoms in adults and it causes less adverse reactions than injections. We are still not completely certain if it is as effective as injections, or whether it works for children. But many more trials are being done and we expect good answers to these questions soon," Professor Peter Sawicki, the Director of the Institute, said.
The Institute also examined the latest research on some of the biggest-selling anti-histamines.
They can all relieve symptoms, but adverse effects are common with all of them.
Some might provide relief more quickly than others, and some might have more adverse effects.
The Institute also looked at what might work to prevent allergies developing in children and came to several conclusions.
If the parents quit smoking, this can help. Some infant formulas can occasionally cause some allergies. And there are early signs that pregnant women taking probiotics late in pregnancy might be able to help.
"Probiotics in pregnancy is an area of research the Institute will continue to monitor, to see whether trials establish whether or not this can really prevent allergies," Professor Sawicki said.