benadryl plus capsules work to relieve the symptoms of hay fever & other allergic conditions such as pet skin or dust allergies plus associated congestion. these symptoms include blocked sinuses stuffy nose itchy & runny nose itchy & watery eyes sneezing & urticaria (hives & itchy skin rash)., active in 15 minutes, lasts 8 hours, hay fever, dust allergies, pet allergies, skin allergies, contains pseudoephedrine to relieve congestion