Oedema - pitting vs non-pitting
Oedema is swelling due to excess fluids in tissues.
In pitting oedema, pressing on the affected area leaves an indentation (that persists after removing the pressure). In non-pitting oedema, the area feels firm to touch and does not form indentations.
Pitting oedema:
The excess fluid is mainly composed of water
Commonly caused by heart failure, venous insufficiency, or nephrotic syndrome
Non-pitting oedema:
The excess fluid consists of water WITH protein and salts
Usually indicates a condition of the thyroid / lymphatic system
Different types:
Lymphoedema is due to a build-up of lymphatic fluid (e.g. due to a tumour blocking lymphatic flow / after removal of lymph nodes).
Myxoedema occurs in hypothyroidism and often affected the pretibial or periorbital area.
Angioedema is localised swelling of the skin and is usually due to allergic reactions. It typically affects the face, tongue, larynx, abdomen, arms, and legs. When the larynx is affected, it may affect breathing, which is an emergency!
Lipoedema is when fat accumulates in subcutaneous tissues - it usually affects the legs/buttocks and almost exclusively occurs in postpubertal females (not the same as cellulite!)
If patients present with oedema, it's always important to test if it's pitting or non-pitting as this helps to determine the cause and correct treatment!
