my BB have the same when he was 7 months old....Dr also said probably becos of allegy, but cant tell allegy to what....Dr said we have to check by ourself, may be food, may be clothes, may be weather.....
Since my BB also got 濕疹 sometimes, so Dr advised us to take some allegy test....but i study some bloggers web site and some of them found that not so useful to to the test at this age.....may be better when he is bigger, therefore, i did not do anything...
the night before my BB have 風難, he ate chinese tofu, not sure if this is the reason, but i did not give chinese tofu to him anymore, i just give the japanese tofu from now on
my daughter is allergic to milk, cheese, soy bean and many other things, I bought her to see specialist and did a skin test, now i know exactly what to avoid, and she's drinking HP milk powder, u should bring ur baby to see specialist to find out what is causing the reaction