Glossary of terms

Caval compression – the vena cava is a major vein in the body. After 16 weeks of pregnancy the weight of the uterus (womb) can restrict the blood flow through the vena cava if the patient should lie on their back.

Epitopes – allergic markers which are recognised by the immune system.

Mastocytosis – this is a rare condition caused by excessive amounts of mast cells gathering in the tissues of the body. These cells release large amounts of histamine and other chemicals into the blood, causing symptoms such as a skin rash, itchy skin and hot flushes.

Purpuric and petechial rash – Red or purple discolouration of the skin, caused by bleeding under the skin, that do not blanch when pressure is applied. Often seen in Meningococcal meningitis and septicaemia.

Sensitisation – a reaction in which exposure to an antigen produces antibodies, this can subsequently lead to an allergic reaction.

Septic shock – Septic shock is a serious condition often resulting from infection. It can cause multiple organ failure and death.

Stridor  – a harsh lower pitched sound occurring during breathing in, and coming from the larynx and trachea.

Systemic disease – an illness that affects multiple organs, systems or tissues, or the entire body.

Vaso-vagal episode – a fainting episode.