Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain you have got an
allergic reaction to the poisnous chemical left by the wasp stinger under the skin causing the above explained symptoms as well as swelling, pain and
redness are due to localized reaction of the sting at the site of bite..
You should continue taking Zyrtec as it is anti allergic medication and as it has suppressed the
generalized allergy symptoms it will also help in relieving localized symptoms..
Take anti inflammatory painkiller like
Ibuprofen for pain relief..
Do cold packs over the inflamed area..
Take a close look at the affected area and if the wasp stinger is embedded in the skin either remove it yourself or get it removed by a doctor as stinger keeps releasing toxin under skin..
Apply
Steroid based ointment over the swelling..
Apply numbing gel over the swollen and painful area for relief..
If after all this also there is no improvement you should consult your doctor in his clinic and get evaluated as there can also be infection at the injury site which then will have to be treated with antibiotics..
Hope you get well soon..
Thanks and regards..
Dr.Honey Nandwani Arora..