“…20 Although we would now expect to see three to four cases of PCH in 1 year, our experience and that of others is that they often present in small clusters; sometimes two or three occur close together, and at other times, long periods pass without a case being referred. 8,21,22 Paroxysmal cold hemoglobinuria is typically associated with infection 7,10,12,[23][24][25] and this was evident, or implied by the antibiotic treatment, in three of the four patients.There are several case reports of the disease following specific illnesses, including measles, 13 measles immunization, 10 parvovirus, 24 mumps, 25 Klebsiella pneumonia, 12 chicken pox, 7 and upper respiratory tract infections. 7,14,20,26 The condition is most commonly encountered in a severe acute transient form, as in the present cases, and has been the subject of an excellent review.…”