Graphical abstract : Cross reactivity between environmental allergens and TPO, Tg and Il24. Graphical abstract: Some lineal and conformational epitopes for human TPO, Tg and IL24 were proposed, however it seems there is not cross reactivity with enviromental allergens. La IgE anti-TPO puede afectar la piel por qué; • La TPO o el complejo IgE anti-TPO, llega a la piel y es reconocida por FceRI. • La TPO tiene similitud con una molécula de la piel; la IgE reconoce la de la piel por su similitud con la TPO o viceversa; la IgE reconoce la TPO por similitud a una proteína de la piel. (¿epidermal FABP, profilina, queratina, filagrina?). • Una proteína sérica, con similitud con la TPO (¿IL24, factor tisular?) que llega a la piel. • TPO similar a una proteína externa que llega a la piel (¿aeroalergenos?). • In silico analysis allowed to identify antigen patches of human proteins TPO, Tg and IL24. • These antigen patches could explain the autoreactive response in chronic urticaria and hypothyroidism. • There was no cross reactivity between the identified antigen patches and the tested environmental allergens. Human proteins such as interleukin-24 (IL24), thyroperoxidase (TPO) and thyroglobulin (Tg) are targets of IgE or IgG autoantibodies. Why these proteins are recognized by autoantibodies in some patients with chronic spontaneous urticaria (CSU) or hypothyroidism is unknown. Through in silico analysis, identify antigen patches of TPO, Tg and IL24 and compare the sequences of these human proteins with some prevalent allergens. The amino acids sequences of IL24, thyroperoxidase and thyroglobulin were compared between them and with 22 environmental allergens. Phylogenetic studies and multiple pairing were carried out to explore the degree of protein identity and cover. The proteins without 3D structure reported in the database, were modeled by homology with "Swiss Modeller" and compared through PYMOL. Residues conserved and accessible to the solvent (rASA> 0.25) were located in the 3D model to identify possible areas of cross-reactivity and antigen binding. We build a 3D model of the TPO and thyroglobulin protein base on proteins closely related. Five epitopes for TPO, six for IL24 and six for thyroglobulin were predicted. The amino acid sequences of allergens from different sources (Dermatophagoides pteronyssinus, Blomia tropicalis, Betula verrucosa, Cynodon dactylon, Aspergillus fumigatus, Canis domesticus, Felis domesticus) were compared with human TPO, Tg and IL24. The cover and alignments between allergens and human proteins were low. We identify possible linear and conformational epitopes of TPO, Tg and IL24 that could be the target of IgE or IgG binding in patients with urticaria or hypothyroidism; These epitopes do not appear to be present among common environmental allergens, suggesting that autoreactivity to these human proteins are not by cross-reactivity. [ABSTRACT FROM AUTHOR]