[trallnag]

What kind of evidence are you expecting? Many diseases are treated with antibiotics without definitive evidence via some kind of test. Often, evaluating symptoms is deemed sufficient. For example, in the case of Erysipelas, an infection of the skin

[epcoa]

The commenter did not expound on any specific evidence that would suggest a bacterial lung infection. 2 weeks of malaise and non specific upper respiratory symptoms is not strong evidence of a bacterial pneumonia, sorry.

For external infections, observation by visible inspection is still evidence, a sign, not a symptom. So, not sure what your point is. Erysipelas is invariably diagnosed by signs, not symptoms. Very rarely are bacterial infections diagnosed by symptoms alone.

[trallnag]

The difference between symptoms and signs was unclear to me. Just checked. Thanks