Hello Sir..i Have An Ellergic Problem On Skin..redness,itching In Sunlight

hello sir..i have an ellergic problem on skin..redness,itching in sunlight specially,swalling..i have used softin tablets(loratadine 10 mg) almost 2 weeks...the problem was diminished ..but after 4 months later it appears again slowly .can i use this again?is it have side effects?how i use it?how long i use it now to relief this probles permanently