IgM response to appear in 15 mn and decrease in 1h unless followed by a delayed reaction (type III reaction occuring 5:00H later or type IV 12:00H later).
Brostoff J, Scadding GK, Male D, Roitt IM. Immunologie clinique. De Boek Université 1993,438pp.
But in my experience some atopic patients have marked tuberculinic skin test reactions without however being infected with BK...