Arrange for follow up if symptoms persist or worsen, or if new problems develop. Most colds are self-limiting illnesses, and many treatments may appear to work by coincidence alone. Do not prescribe inappropriate antibiotics simply because you suspect the insistent patient will obtain them elsewhere. This is not justification for poor medical practice. Do not undertake expensive diagnostic testing on uncomplicated cases.
Bacterial superinfections require antibiotics.
Mycoplasma pneumonia can present with headache, cough, myalgias, and perhaps bullous myringitis, and may respond to erythromycin. Coughing can precede wheezing as an early sign of asthma, and response to beta agonists helps make the diagnosis. Antibiotics have not turned out to be very useful for acute bronchitis, and vitamin C as prophylaxis for colds has also not done well in controlled trials.