A method of image-based quantification for allergen skin reaction includes imaging an area of skin that has been subject to a skin-prick test to produce one or more images of the area. The method includes identifying regions of wheal and/or flare in the one or more images of the area and quantifying weal and/or flare indicators based on the regions identified. The method also includes outputting results of the quantified wheal and/or flare indicators indicative of quantified allergen skin reaction.