Brief Answer:
Allergy vs dermatitis...

Detailed Answer:
Hi,

Though not common some individuals develop itchy rash after exposure to sun. The changes are allergic in nature and described as polymorphic light eruption.

May I know what medication was prescribed for urticaria 2 years ago?
I will suggest to start antihistamine drugs like tab levocet 5mg at night one tablet for few days to treat the itching and rashes.
Use sunscreen agents and a moisturizing agent on the affected area.

I also recommend a visit to a dermatologist for further evaluation and treatment.

Hope this helps. Let me know if you need clarifications.

Regards

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