How is late onset Type I HS?

➢ In some cases, a late onset reaction may occur after allergen exposure and the acute response. The immediate allergic reaction caused by mast-cell degranulation is followed by a more sustained inflammation, known as the Late-phase reaction (LPR). ➢ This late response involves the recruitment of other effector cells, notably TH2 lymphocytes, eosinophils, and basophils, which contribute significantly to the immunopathology of an allergic response ➢ LPR occurs hours after immediate reaction. It generally peaks at about 6–12 h and subsides at about 24 h. The LPR can last hours to days (24-72 hours). ➢ Signs and symptoms of delayed or late-phase allergic reactions are generally the same as those for immediate allergic reaction