I was told about low cholesterol in an off-handed comment by my doctor while he was inspecting an FBT for the cellulitis I am treating that low cholesterol is bad for you.
Is this true? Is it bad to have low cholesterol?
In the following, I assume you meant total cholesterol and not HDL or LDL-cholesterol.
Low cholesterol can be found in some rare genetic diseases, and in people affected by other illnesses. For example, hyperthyroidism will cause low cholesterol because it fastens the metabolism and increases the use of lipids in general. Any illness that involves inflammation will be likely to lower the cholesterol blood level as well.
People affected by metabolic disorders and who have to follow a strict diet (especially hypoprotidic ones, like phenylcetonuria) will often have low cholesterol.
Additionally, children often have low cholesterol because cells use cholesterol to expand and multiply, and the growth period therefore use a lot of cholesterol.
As for the risks associated with low cholesterol, there is still little research on the subject. Low cholesterol seem to be a bad prognosis factor for severely ill patients, and associated with stroke, infections or mental illnesses. However, it is unclear if the cholesterol level is just a marker of the risk (a consequence) or a cause.
Like all biological factors, it'd be probably interesting to do another test to see if this low cholesterol happened just once or if it's a trend. Since you're being treated for cellulitis, it's likely that this infection is responsible for your current low cholesterol (which would be confirmed if your cholesterol returns to normal after treatment).
Sadly I can't be more precise than this answer as there is, as far as I know, no specific study on cholesterol levels in people treated for cellulitis.