Sinus suggestions?
Sometimes when I get a tension type headache my sinuses get congested too.
It may not be allergies.
If it is an ongoing problem, he should get checked out by a Dr.
This is what I do for myself and clients:
Pressure points and facial massage.
Apply pressure to all areas around the eyes, nose, and across the forehead (frontalis).
Apply pressure to the eyebrow area below the actual brow (orbicularus oculi).
You could have him try and apply a cold compress to his face or add that into your session with him.
Some EO's in steam on the face can help also (he can do this with a pot of water at home-caution not to make it too hot-water should not be boiling).
Most clients get sinus issues from being prone. Sometimes adjusting your face cradle cushion can help. Some cushions press on the face and can cause sinus pain.
Oblas is a good product for sinus problems:
http://www.olbas.com/index.html
HTH!