Hello and welcome to healthcaremagic
I would keep a possibility of Acute Urticaria. It presents as itching and skin welts/swellings, which can be distributed all over the body.
Urticaria OR hives can occur due to various causes like(to name a few):
--Infections(bacterial , viral, fungal)
--Drugs(Pain killers/ antibiotics etc)
--Certain foods and food additives/preservatives
--Physical Urticaria: Cold temperature, Heat, Pressure(Prolonged Standing, Sitting), Dermaographism etc.
--Cholinergic Urticaria: in response to strong emotions, exercise, spicy food etc --
Autoimmune disorders like SLE, RA etc.
--A few cases have no underlying cause and are known as idiopathic urticaria
An oral antihistamine like
Fexofenadine (Allegra 180 mg tab) OR
Loratadine (Alaspan 10mg tablet) once or twice daily for a week would be suitable. They are non-sedating and wont affect your alertness level.
If I was your treating doctor I would have also given you a shot of injectable antihistamines like Avil(
pheniramine) and Injectable effcorlin(
hydrocortisone) for rapid relief.
A topical soothing lotion like calamine would help you symptomatically.
take care
regards