Itching without rashes. Kindly advise.

Onset of one year duration Last year itching along with rashes during summer. Subsided after summer. Though Minimum itching without rashes continued. Aggravated again now with summer again. Relieved with antihistamines. Itching more on fingers and legs. Neck and scalp second area commonly affected. Lately becoming bothersome at night after which need to take antihistamines. Aggravated on exercising esp on hands. Last year this was the same area ( hands and scalp) where I had applied ice to relieve itching. since 1.5 years using hair dye. Blood counts normal Liver function and kidney profile normal limits. Blood sugar normal. Cholesterol .. border line higher side. Confused whether this is allergy or prickly heat! Already consulted neurologist and dermatologist. So taken vitamins and antihistamines. Kindly advise.. Thank you