Research presented at an allergy conference in 2010 suggests that another person's saliva can present problems for an allergic person even hours after eating. Brushing your teeth may help, but it may not be enough, Bassett said. Talk to your partner about his or her level of comfort regarding what you eat before smooching.

Beware of scented creams and oils

Massage oils, lotions and fragrances can all have ingredients that make people break out into rashes; ask ahead of time if there are particular chemicals or essential oils that cause problems.

Almond and macadamia nut oils, for instance, may be present in common beauty products. Keep this in mind also for purchasing gifts.

If you're going all the way ...

Some people are allergic to latex. If you are planning on using condoms, be aware if your lover has a latex allergy and use a nonlatex condom if so. Tests are available to confirm if someone is hypersensitive to latex.

Be understanding and supportive

A willingness to take extra precautions surrounding allergies, especially life-threatening food allergies, will go a long way.

Everyone with food allergies should have an anaphyalxis action plan that they discuss and formulate with their doctor, and you should be familiar with it, too.

An epinephrine auto-injector, which people with severe food allergies are recommended to carry, can save a life if symptoms such as shortness of breath, throat closure and dizziness appear. After using one, a patient will may still need emergency medical attention, so call 911 or go to the nearest hospital emergency room.

You should know where the appropriate medications are kept and what your significant other's emergency contact information is in case you need to go to the hospital.

Lastly, Miller said, remember to remain focused on the point of Valentine's Day -- "being together, expressing affection, support and love to each other."