Might b caused by the weather? Heat rash? My boy is always 'botak'. Everytime his hair grow to a certain length he scratch his head when its hot. Notice that he scratches when he perspire. So i assume that its the sweat made the head like ticklish. During one to two mths after shave no scratching issue. Once the hair grows to those spiky length he starts to scratch when its hot, like the sweat 'accumulate' in between the hair.
Our family all loves cold hates warm. My younger bro was worst, when he was lil he has to go botak cos once weather turns warm there will b red patches on head neck back area. Once its cool the patches go away..