Skin rash on arms and around neck

[Codus]

So more than a week ago my arms became very itchy and rash (small light red pimples) started to develop. Around same time same itchy rash started to develop around neck (basically between breasts and neck). Sometimes itch goes away or becomes almost unnoticeable, but sometimes (mostly around evening, before sleep) it becomes unbearable so I start to scratch them.
Could it be scabies? Or some sort of allergy (but my lifestyle haven't really changed for last couple of weeks).
In these pictures you can see rash:  
So more than a week ago my arms became very itchy and rash (small light red pimples) started to develop. Around same time same itchy rash started to develop around neck (basically between breasts and neck). Sometimes itch goes away or becomes almost unnoticeable, but sometimes (mostly around evening, before sleep) it becomes unbearable so I start to scratch them.
Could it be scabies? Or some sort of allergy (but my lifestyle haven't really changed for last couple of weeks).
In these pictures you can see rash:  

http://bildites.lv/images/vq35532b/29730/original.jpg
http://bildites.lv/images/hrdftvp9/29731/original.jpg