Reddish Blotches On The Forearms In Summer. Have Itching. Allergy?

I'M AN ASIAN WOMAN FROM THE PHILIPPINES,OF 57 YEARS OLD,OF GOOD HEALTH,MY CONCERN IS THAT EVERY COMING OF THE SUMMER TIME MY SKIN IN THE FOREARMS(BOTH)ITCHES AND RED BLOCHES APPEARS,LIKE ECZEMA,IT HAS LITTLE PIGMENTATION LIKE A RINGWORM,I WASH IT EVERYTIME AND PUT SOME SKIN OINTMENT,HYDROCORTISONE 1% FOR ITCH,THEN WASH IT WITH MY SELSUN BLUE SHAMPOO WHEN ITS SO ITCHY,WHEN THE HOT SEASON IS DONE,MY ITCHY THING IS GONE TOO,I CANT EAT ANYTHING LIKE CHEESE,SEA FOOD,PORK FOR IT BECOME ITCHY,PLEASE HELP,