What is the clear fluid inside a blister?
This question came up the other day in mixed company, and we can’t find the answer anywhere. It’s driving us crazy, so we thought we’d go to the experts.
My Dorland’s gives blood blister : blood/water blister : clear watery contents. Then there are herpes blisters.
Checking under ‘lymph’, the second definition is any clear water fluid resembling lymph. The definition of lymph is long, so will not include it.
Hope this helps.
IANADoctor, but I say it’s lymphatic fluid. As you may or may not know, your body has two circulatory systems: one for blood, and one for lyphatic fluid. This contains lots of complex things useful for fighting disease and such. I’m sure someone more qualified can be more specific, but that’s never stopped anyone here posting. 
I would agree with lymphatic fluid or a mass amount of cytoplasm from the cells one has ruptured with a burn or friction.
I am not a physician nor a doctor of any sort nor have I ever played one on TV, radio, etc. I am a translator and so therefore work with language. I agree that ‘lymph’ as the name of the fluid sounded strange to me as well and I have probably only heard ‘lymphatic fluid’ myself, but Dorland’s Illustrated Medical Dictionary does not list ‘lymphatic fluid’. It does list ‘lymphatic’: ‘pertaining to lymph or a lymph vessel; by extension, the term is used alone to designate a lymphatic vesel or, in the plural, to designate the lymphatic system.’
Since there seems to be some question about ‘lymph’, will quote that definition as well, ‘a transparent, slightly yellow liquid of alkaline reaction, found in the lymphatic vessels and derived from the tissue fluids. …[about colour]… Under the microscope, lymph is seen to consist of a liquid portion and of cells, most of which are lymphocytes. Lymph is collected from all parts of the body and returned to the blood via the lymphatic system. Called the lympha.’
Lympha: ‘the fluid found in the lymphatic vessels.’ This would be the Latin term.
Dorland’s is published in Phil. PA
Blakiston’s GOULD MEDICAL DICTIONARY (McGraw-Hill) seconds the opinion.
Now that we have a small problem of a difference in expert opinions and the authors of the books are not answering questions (I think), could you possibly shed some light on this so that my translations will be correct. Thanks for the help.
When the skin is irritated, local capillaries respond by getting “leaky” so blood fluids, cells, and chemicals migrate from the circulatory system.
Therefore, blister fluids in general are ultra-filtrates of blood and generally may contain some unique components based on what caused the blister (herpes blister fluids contain herpes virus, allergic blister fluids contain eosinophils). As such they usually are full of protein and electrolytes, and also inflammatory mediatiors.
QtM, MD
And poison ivy blisters do not contain material that will spread the rash, right Qadgop? Isn’t it the same stuff you mentioned above that’s in a allergic blister?
A topical irritant rash such as poison ivy would be spread by touching it because the irritant material is still on the skin (or clothes) surface, not in the fluid. The fluid in this case would be mostly products of an inflammatory response. The body would not manufacture more of the irritant chemical (which came from outside the body in the first place), or in most cases be able to localize it or concentrate it. The body uses the immune response to try to keep the irritant chemical from doing further damage/penetrating further.
But if the blister fluid is due to infection, it will contain infectious agents.