Skin itching heavily from past 8months.

Hi.. This is Rajesh and i am 25 years old. Whenever my body temperature rises .. even a slight increase in temperature leads to crazy itching all over my body (needle itching) After a little scratching that portion becomes red.. Situations when i suffer this itching problem- 1. Exposure to Sunlight(cannot stay for 1min also in sun or hot place) 2. Whenever I feel Nervousness, Anxiety and anger 3. Eating spicy hot food (itching on scalp) 4. When my body heats up due to physical workout besides even making a little scratch on my body makes that part red . 5. If I sweat single drop. Am seeing hives on hands, chest and entire body itching it's not bearable.( images attached) 6. Some times itching making me to wake up from sleep. All most all medicines I use but not cured Allegra Atarax Teczine Rantac Alaspan Polaramine Please help me With your suggestion.