Sickle cell crises (aplastic)

Aplastic sickle cell crises occur when the bone marrow temporarily shuts down. There is an acute fall in haemoglobin levels - by up to 1 g per dl per day - and there is a complete absence of reticulocytes in the blood film.

The characteristics of aplastic crises are that they often occur in children, they occur in epidemics and in families, and they have a very stereotyped clinical course and recovery if treated appropriately.

The causative agent is usually human parvovirus B19. Because of the shortened red cell survival marrow shutdown leads to profound anaemia over a period of a few days.

Aplastic crises is characterised by

• reticulocytopaenia – seen after around 5 days post exposure and continues for 7 – 10 days
• symptomatic anaemia
• serum IgM antibodies to parvovirus B19 (1)

Parental education is very important so that they recognise this condition early and act to prevent fatality.

Reference:

• (1) Okpala I. The management of crisis in sickle cell disease. Eur J Haematol. 1998;60(1):1-6