Clinical and Therapeutic Aspects of Thrombocytopenic Purpura

THE title Morbus Maculosis Werlhofii for the severe form of purpura haemorrhagica is derived from the fact that the first clear and accurate clinical account of this condition was made by Werlhof in 1775. However, over two centuries earlier, a Portuguese called Amatus Lusitanus described in one of his works, under the title of Morbus Pulicaris Absque Febre, the case of a boy with undoubted acute haemorrhagic purpura who had a spontaneous recovery. Indeed, little can be added today to these earlier clinical descriptions which are full of the fruits of keen observation and reflect the scholarship of their age. The disease is characterised by the presence of petechial hoemorrhages in the skin-compared by one earlier worker to "flea bitings." These are more commonly seen in the limbs but may also occur on the trunk. These minute haemorrhages may spread to produce purpuric spots or coalesce to form extensive superficial ecchymoses. Associated lesions are commonly seen in the buccal mucosa where they assume the characters of blood filled blisters. These manifestations are associated with free bleeding from mucous surfaces with epistaxis, hoematuria, haematemesis or persistent oozing from the gums. In women profuse uterine bleeding is not uncommon and may be the presenting sign and reason for the patient's hospitalisation, as it has been in two of our cases. It was not until late in the nineteenth century that Bizzozero (1882) noted the relationship of blood platelets to clot formation and this was quickly followed by the observation in some cases of purpura of a diminished number of circulating blood platelets. Thus, the understanding of the function of blood platelets preceded any knowledge as to their origin, which was the subject of considerable dispute until Wright (1910) clearly demonstrated platelets budding off from the megakaryocytes of the bone marrow. Further study of the relationship of circulating blood platelets to the presence of clinical purpura received intensive study which revealed that there were two major kinds of purpura. In the first of these the number of circulating blood platelets is normal. This is called non-thrombocytopenic purpura and in this type the bleeding is almost certainly due to a disturbance of the walls of blood vessels. In the second type the number of circulating blood platelets is reduced. This is called thrombocytopenic purpura and in this type the bleeding is clearly related to the diminished number of circulating blood platelets although, an associated …