Bleeding diathesis is a term describing a propensity toward bleeding or hemorrhage, which can be a constitutive feature of numerous disorders of vascular, genetic, or autoimmune origin. The diagnosis rests on identifying the underlying cause through a detailed patient history and laboratory workup.
The clinical presentation of bleeding is diverse, and it is imperative to recognize different forms of bleeding that may provide vital information about the underlying cause. Cutaneous (petechiae, epistaxis, purpuric spots, ecchymosis) or mucosal bleeding (for eg. gingival or conjunctival bleeding) rises suspicion toward platelet disorders (such as thrombotic thrombocytopenic purpura (TTP), splenic sequestration or drug-induced thrombocytopenia) and vascular abnormalities  . Muscular, parenchymal, intracavitary (hemoperitoneum, hemothorax), or orificial bleeding can point to disorders of impaired coagulation, including hemophilia A and B, vitamin K deficiency, celiac disease, von Willebrand disease (vWD) and many other   . In fact, a tendency towards bleeding can be the first manifestation of patients with celiac disease (CD) . In addition to the type of bleeding, signs such as excessive hemorrhage from cuts, easy bruising or intracranial bleeding may suggest some form of coagulopathy as well (vitamin K deficiency or any of the inherited genetic disorders)  . Menorrhagia, especially when present in younger women, is a diagnostic hallmark of bleeding disorders in this population. The onset of bleeding is also an important clue, as bleeding diathesis may last throughout the entire childhood or just for a few days, depending on the underlying cause. Hepatosplenomegaly, tachycardia, skin or conjunctival pallor, and anemia presenting with a heart murmur are other notable symptoms. In very rare cases, eczema and recurrent infections accompanied by frequent bleeding episodes are highly specific for Wiskott-Aldrich syndrome, an X-linked genetic disease .
A detailed patient history should be obtained in all patients with a bleeding diathesis, as it may reveal key findings such as prior use of aspirin or anticoagulant therapy, a prolonged duration of symptoms and the familial presence of bleeding disorders  . The type and severity of bleeding noted during the physical examination are pivotal as well, but to determine the underlying cause, an extensive laboratory workup is necessary. A complete blood count (CBC) can detect anemia and more importantly thrombocytopenia (defined as platelet count <150,000/μL), which may occur either as a result of impaired function or insufficient production of platelets. Initial workup should also comprise prothrombin time (PT) and activated partial thromboplastin time (aPTT), to determine whether the extrinsic or intrinsic pathway is disturbed . Prolonged PT suggests factor VII deficiency, while hemophilias A and B, Von Willebrand disease, and deficiency of factors XI and XII are the most likely causes of bleeding if aPTT is prolonged . If both extrinsic and intrinsic pathways are defective, vitamin K deficiency, liver disease, use of anticoagulant therapy or deficiency of factors V, X, or II must be considered in the differential diagnosis . Additional procedures include a peripheral blood smear, platelet function analysis (PFA), thrombin time, inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein, fibrinogen and D-dimer), as well as the determination of individual coagulation factors  .