Allergy disease history has been identified as a risk factor for increased AA susceptibility and a strong genetic link exists between AA and atopy (allergic rhinitis, atopic dermatitis, asthma) through the interleukin 13 and CLEC16A/KIAA0350 susceptibility loci, which have been identified in AA and other diseases such as psoriasis and arthritis.23 This evidence concerns the gene IL13 and arthritic joint disease.