Antihistamines are for any kind of allergy. They don't care if it's from breathing in something, touching something, or eating something. Allergy is an allergy.
Were they thinking, "The patient might find these handy if they have pollen allergies but never really thought to do anything about it"?
Or, were they thinking, "The patient doesn't seem to know if they're allergic to this prescription I'm giving them, so I'll give them an antihistamine to go along with it just in case."
