Possibly you are twisting the pinky inward toward the palm as you rest your hand down to pin. If the pain decreases susbtantially within a week or two of not pinning or using it you have your answer. If not- you may have arthritis, perhaps gout. The itchiness is likely from the heat of the inflammation rather than allergy if you prewash your fabrics. Let us know how it turns out. Get better soon!