What will make my shoulder tattoo stop itching?

I have quite a few tattoos, all well past healed. All are fine but one. My largest one, covering my entire shoulder from under my collar bone down onto my shoulder blade, has been really itchy in just one small spot with tiny bumps like an eczema breakout for about a week now. My clothes, laundry detergent, perfumes, etc. are all what they have always been. My lotion is an organic lotion containing lavandin oil, sunflower oil, and distilled water. So what is it, and what will make it go away?