Page 345 - Essential Haematology

Chapter 25 Bleeding disorders / 331

Abnormal b leeding usually normal and the other tests of haemostasis
are also normal. Vascular defects may be inherited

This may result from:
or acquired.
1 Vascular disorders
2 Th rombocytopenia
Inherited v ascular d isorders
3 Defective platelet function or
4 Defective coagulation. Hereditary h aemorrhagic t elangiectasia

The pattern of bleeding is relatively predictable Th is uncommon disease is transmitted as an auto-
depending on the aetiology. Vascular and platelet somal dominant trait. Various genetic defects
disorders tend to be associated with bleeding from underlie the disease, e.g. of the endothelial protein,
mucous membranes and into the skin whereas in endoglin. Th ere are dilated microvascular swellings
coagulation disorders the bleeding is often into which appear during childhood and become more
joints or soft tissue (Table 25.1 ). numerous in adult life. These telangiectasia develop

Th e first three categories are discussed in this chapter in the skin, mucous membranes (Fig. 25.1 a) and
and the disorders of blood coagulation follow in internal organs. Pulmonary, hepatic, splenic and
Chapter 26 . cerebral arteriovenous shunts are seen in a minority
of cases. Recurrent epistaxes are frequent and recur-
rent gastrointestinal tract haemorrhage may cause
Table 25.1 Clinical differences between chronic iron deficiency anaemia. Treatment is with

diseases of platelets/vessel wall or of
coagulation factors. embolization, laser treatment, oestrogens, tran-
examic acid and iron supplementation.
Platelets/vessel Coagulation

wall diseases diseases
Connective t issue d isorders
Mucosal Common Rare
In the Ehlers – Danlos syndromes there are
bleeding
hereditary collagen abnormalities with purpura
Petechiae Common Rare resulting from defective platelet aggregation, hyper-
Deep Rare Characteristic extensibility of joints and hyperelastic friable skin.
haematomas Pseudoxanthoma elasticum is associated with arte-
rial haemorrhage and thrombosis. Patients may

Bleeding from Persistent Minimal

skin cuts present with superficial bruising and purpura fol-
lowing minor trauma or after the application of a
Sex of patient Equal > 80% male tourniquet. Bleeding and poor wound healing after
surgery may be a problem.
Vascular b leeding d isorders
Giant c avernous h aemangioma

The vascular disorders are a heterogeneous group of

conditions characterized by easy bruising and spon- These congenital malformations occasionally cause
taneous bleeding from the small vessels. Th e under- chronic activation of coagulation leading to labora-
lying abnormality is either in the vessels themselves tory features of disseminated intravascular coagula-
or in the perivascular connective tissues. Most cases tion (DIC) and in some cases thrombocytopenia.
of bleeding caused by vascular defects alone are not
severe. Frequently, the bleeding is mainly in the skin
Acquired v ascular d efects
causing petechiae, ecchymoses or both (Fig. 25.1 ).
In some disorders there is also bleeding from 1 Simple easy bruising is a common benign disor-
mucous membranes. In these conditions the stand- der which occurs in otherwise healthy women,

ard screening tests are normal. The bleeding time is especially those of child - bearing age.