lab like RANBAXY ,RELIGARE are doing allergy
test with different allergen more then 200.
it has branch all over india .so take contact no from net and ask them detail.
there are different allergen like food ,inhale ,drug,chemical etc
one thing i like to tell u that urticaria
is unpredictable condition and take 2 month to 20 yr to resolve
so take only antihistamine tab for it ,do not take steroid