constantly wiping face - habit or irritation?

[Linz2]

Not sure whether my 2 year old has developed a habit or something is irritating his skin although nothing new has been introduced food wise or in the house. A couple of weeks a go he started to wipe his eyes/nose/cheeks not rubbing or scratching but wiping. We did think that maybe he was developing conjunctivitus as he had come into contact with a child we thought had had it but then a week last saturday he got chickenpox and did seem to stop doing it, however he is over chicken pox now and he has started doing it again in the last day or so! His hair is worn a bit longer but not in his eyes but am going to get it cut off asap incase it is his hair bothering him!, although he has had longer hair for a while and did not do it until last 2 weeks. I did ring the docs a week or so back who suggested that it could be the start of a cold but obviously has not got this.Anybody had any experience of this and how to deal with it as if it is just a habit I do not want him doing it as he will make his face sore constantly wiping it.