We describe a 23-year-old patient who presented acutely with haemophagocytic lymphohistiocytosis (HL) and Melkersson-Rosenthal syndrome (MRS). MRS and HL are two unusual and complex clinical patterns that may present acutely and to our knowledge, an association between them has never been reported. The clinical investigations in this patient led to identification of parvovirus B19 (PB19) viraemia by PCR. Parvovirus infection has been reported as a cause of virus-associated HL, but the presence of PB19 has never been sought or reported as a possible trigger for MRS. This observation suggests a possible association between PB19 and HL, and opens the possibility of its association also with acute-onset MRS. Further investigations for the presence of PB19 in cases of MRS are warranted.