While it is possible to have an allergy to gold, it is rare - far more rare than reactions to metals like nickel used in white gold alloys, for example. They used to almost always use gold to cap teeth with because it is typically non reactive. My skin eats gold plating away and alloys under 14K discolour on me, but they do not irritate my skin.
CAN an allergy develop? I suppose it could, but then again, you COULD develop an allergy to the fabrics in the clothing you wear, the detergent you use to wash, the perfume you wear, the cosmetics you use, or any pets you might have. In other words, a metal allergy is not any more or less likely to occur than any other reaction, and to fear buying gold when you have worn it without issue in the past is slightly irrational, IMO.
CAN an allergy develop? I suppose it could, but then again, you COULD develop an allergy to the fabrics in the clothing you wear, the detergent you use to wash, the perfume you wear, the cosmetics you use, or any pets you might have. In other words, a metal allergy is not any more or less likely to occur than any other reaction, and to fear buying gold when you have worn it without issue in the past is slightly irrational, IMO.