HI ! Possibly you are getting some kind of hypertrophied scars
over your tattoo pricks, which is now inflammed. If infection is excluded, then you can start some steroidal cream for local application. The cough
along with the bad throat possibly is not be related to this and is just coincidental. If the red bums are increasing, then I would suggest you to see a Dermatologist
in your area. Wishing you an early relief of your symptoms.