I have had the same exact thing for 3 yrs....I have tried the allergy specialist done the testing and nothing conclusive. I take Zyrtec and Zyzol no help. The swelling can be in my face, feet or arms....all I hear is its idiopathic recurring angioedema......I WISH WE COULD FIND AN ANSWER!
Ive had something similar happen too. Out of nowhere my lip started swelling. Ive had it happen several times. I know its some sort of allergic reaction but it could be from almost anything. I say see an allergist as well. good luck
Has something in his diet changed or soap, after shave, Does his tongue swell
I suggest he should see an Allergist and or a Dermatologist!