Swelling differential- Fluid
- Overgrowth
- Tumour
- Shrinkage of t'other side
Fluid flow
- Net pressure is OUT OF capillaries over their entire length
- => There is no venous reabsorption of fluid
- => Lymphatics do it all
- NB this is not what used to be taught
Lymphatic failure
- Filtration oedema
- Lymphatics still functional, just overloaded
- e.g. In acute heart failure
- Pits easily as fluid is still flowing fine
- Lymphoedema
- Damage to lymphatics
- e.g. From sustained filtration oedema
- Pits at early stages
- Non-pitting later on
Lymphoedema stages
- Stage 0 (latent):
- Vessel damage but transport capacity is still sufficient for the amount of lymph being removed
- Lymphedema not present
- Stage 1 (spontaneously reversible)
- Tissue is still at the "nonpitting" stage
- Usually upon waking in the morning, the limb or affected area is normal or almost normal in size
- Stage 2 (spontaneously irreversible)
- The tissue now has a spongy consistency and is considered "pitting"
- Fibrosis found in stage 2 lymphedema marks the beginning of the hardening of the limbs and increasing size
- Stage 3 (lymphostatic elephantiasis)
- Swelling is irreversible and usually the limb(s) or affected area is very large
- The tissue is hard (fibrotic) and unresponsive
Milroy's disease
- VEGFR-3 mutation => Spontaneous oedema
Distinguishing features of lymphoedema (vs filtration oedema)
- Only slightly helped by elevation
- Diuretics don't help
- >1 attack of cellulitis
- Due to reduced immune cell trafficking
- Exercise helps
- Pitting
- Skin thickening/hyperkeratosis
Notes
- Lymphatics
- Small collecting ducts
- Large draining ducts, with valves + smooth muscle
- Don't confuse lipodermatosclerosis with cellulitis
- Requires elevation and compression, not antibiotics
- CCBs block lymphatic smooth muscle pumping and can cause lymphoedema
- Plexiform neurofibroma
- Brown spots + swollen leg
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