Capillary Fragility Test & Vascular Bleeding Disorders

A set of 45 vocabulary flashcards summarizing essential terms, disorders, procedures, and factors related to the Capillary Fragility Test and primary hemostatic abnormalities.

Capillary Fragility Test (CFT)

A diagnostic procedure that assesses the ability of capillary walls to withstand elevated hydrostatic pressure without rupturing and forming petechiae.

Tourniquet Test

Common name for the Capillary Fragility Test in which a blood-pressure cuff or tourniquet is used to create controlled venous congestion.

Rumpel-Leede Test

Historical synonym for the tourniquet (capillary fragility) test, named after the physicians who described it.

Hydrostatic Pressure (CFT context)

Increased intravascular pressure produced by cuff inflation that challenges capillary wall strength during the test.

Anoxia (CFT context)

Transient oxygen deprivation of capillary endothelium created by venous congestion in the tourniquet test.

Petechiae

Small (<2 mm), non-blanching, red-purple macules caused by capillary leakage of blood into the skin.

Purpura

Medium-sized hemorrhagic skin lesions (>2 mm and ≤1 cm) formed by coalesced petechiae or vascular inflammation.

Ecchymosis

Large (>1 cm) irregular areas of subcutaneous bleeding, commonly called bruises.

Hematoma

A localized collection of blood in tissue or a body cavity that often elevates the skin or causes pain and swelling.

Primary Hemostasis

The initial platelet-dependent phase of clot formation producing a temporary platelet plug at the injury site.

Secondary Hemostasis

The coagulation-factor–mediated phase that stabilizes the platelet plug with a fibrin-rich clot.

von Willebrand Factor (vWF)

Multimeric plasma protein that mediates platelet adhesion to the vessel wall and stabilizes factor VIII.

Mucocutaneous Bleeding

Surface bleeding from skin or mucous membranes, typical of primary hemostatic defects such as thrombocytopenia.

SBP (Systolic Blood Pressure)

The peak arterial pressure during ventricular contraction; needed to set cuff pressure for the tourniquet test.

DBP (Diastolic Blood Pressure)

The lowest arterial pressure during ventricular relaxation; combined with SBP to calculate mid-cuff pressure in CFT.

Positive CFT Result

Finding of ≥10 petechiae per 1 sq inch (or ≥20 for higher specificity) after the tourniquet test, indicating capillary fragility.

Specificity (CFT)

Ability of the test to correctly identify patients without capillary fragility; rises when the petechiae cut-off is increased.

Sensitivity (CFT)

Ability of the test to detect true capillary fragility; decreases when higher petechiae thresholds are used.

Defervescence

Phase when fever subsides; tourniquet test is more likely to be positive near dengue defervescence.

Thrombocytopenia

A decrease in platelet count that weakens capillary support and predisposes to petechiae and a positive CFT.

Platelet Function Defect

Qualitative platelet abnormality that impairs aggregation and capillary wall protection despite a normal count.

Glanzmann Thrombasthenia

Inherited platelet disorder marked by absent GPIIb/IIIa receptors causing defective aggregation and bleeding.

Bernard–Soulier Syndrome

Rare platelet disorder due to GPIb deficiency, leading to giant platelets and impaired vWF-mediated adhesion.

Hereditary Hemorrhagic Telangiectasia (HHT)

Autosomal-dominant vascular disorder with mucocutaneous telangiectasias and arteriovenous malformations.

Ehlers-Danlos Syndrome (EDS)

Connective-tissue disorder with collagen defects causing hyperextensible skin, joint laxity, and fragile vessels.

Scurvy

Vitamin C deficiency that impairs collagen synthesis, leading to gum bleeding, petechiae, and poor wound healing.

Senile Purpura

Easy bruising in elderly patients due to dermal atrophy and fragile superficial vessels on sun-exposed skin.

Henoch-Schönlein Purpura (HSP)

IgA-mediated small-vessel vasculitis presenting with palpable purpura, arthralgia, and abdominal pain.

Vasculitis

Inflammatory destruction of blood-vessel walls by autoimmune or infectious processes, causing purpura and ulcers.

Capillary Integrity

Structural soundness of capillary walls that prevents leakage of red cells under physiological pressure.

Quick’s Method

Variant of the tourniquet test using 80–100 mm Hg pressure for 1–3 minutes to screen for capillary fragility.

Gothlin’s Method

CFT variant applying 35 mm Hg on both arms for 15 minutes; >12 petechiae indicates fragility.

Hess Test (Suction Test)

Capillary fragility assessment in which negative pressure (≈200 mm Hg) is applied to the skin to provoke petechiae.

Pressure Influence (CFT)

Excessive cuff pressure may cause false-positive petechiae, whereas insufficient pressure may yield false negatives.

Skin Type Influence

Thin, fragile, or diseased skin elevates the likelihood of petechiae formation independent of true capillary weakness.

Medication Influence

Use of aspirin, anticoagulants, or steroids can heighten bleeding tendency and alter CFT results.

Temperature Influence

Cold-induced vasoconstriction can obscure petechiae; warm environments may accentuate their visibility.

Physical Activity Influence

Recent vigorous exercise increases capillary permeability and can exaggerate petechiae formation during CFT.

Contraindication (CFT)

A condition in which performing the test is inadvisable due to risk of harm or unreliable results.

Severe Anemia

Markedly low hemoglobin that, along with bleeding disorders like hemophilia, makes CFT potentially hazardous.

Platelet Dysfunction Disorder

Any hereditary or acquired condition (e.g., Bernard-Soulier) that impairs platelet function and skews CFT results.

Anti-Platelet Drugs

Medications such as aspirin or clopidogrel that reduce platelet activity and may produce false-positive CFTs.

Major Bleeding

Hemorrhage causing death, critical-organ compromise, ≥2 g/dL hemoglobin drop, or need for ≥2 PRBC units.

Reference Values (CFT)

Expected petechiae counts: 0–10 normal, 10–20 borderline, >20 abnormal indicating fragile capillaries.

Capillary Resilience

The capacity of microvessels to withstand mechanical or hypoxic stress without rupturing.