In view of gradually rising incidences of allergic diseases that are often associated with an infection, which can exacerbate allergic reaction [21], here, we found that serum levels of TNF-α and IL-6 in PGN-challenged OVA allergic mice were significantly increased as compared with only OVA allergic mice, but anti-T20 treatment markedly attenuated their increase. Here, IL6 is linked to infection.