Small lumps and swellings (possible allergy?)

[Hocksy_Funter]

One of our horses has quite a few small 'under skin' lumps and bumps running all down the underside of his neck and one or two around the rest of his body. They showed up first around the time of the spring grass coming through and we put it down to a reaction to the new grass. They then went away but have come back again. They seem painless to him. He shares a field with 4 other horses and none of them show any similar signs. They look like a reaction or allergy to something. We only had him last September so don't know what he was like this time last year. He does wear a high neck fly sheet, mainly to keep him clean. Any suggestions appreciated?

Thanks, HF.

 

[jojo180]

my horse has lumps come up due to fly bites, he is just more sensitive than the others. he gets them every where, only in summer while flies are about then they start to reduce within few days/week, there not painful or itchy to him.
the first year i had him it worried me, as they reduced the skin became flacky but he just has bad reactions to them.
He's in a full fly rug now because of this, i did once forgot to put his nose zip on his fly mask and his bottom part of nose came up swollen poor boy but he isn't at all bothered by them