Hi,
It sounds like your friend may be experiencing an 
allergic reaction to either the 
Combiflam or the prawns. Allergic reactions can range from mild to severe, and it's important to take them seriously.
Here are some steps your friend can take urgently:
- Stop taking Combiflam or eating any more prawns.
- Wash the affected area with mild soap and water to remove any allergens.
- Apply a cool, damp compress to the affected area to help reduce itching and inflammation.
- Take an over-the-counter antihistamine like 
cetirizine or 
loratadine to help relieve symptoms like itching and swelling.
If the symptoms are severe or the 
rash is spreading rapidly, seek emergency medical attention. Your friend needs to avoid taking Combiflam in the future and to speak with a doctor about alternative pain relief options. They should also avoid eating prawns or any other known allergens.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Priyanka, General & Family Physician