[Non-pneumococcal bacterial pneumonias (II). Respiratory infections by Mycoplasma and Chlamydia. Viral pneumonias].

Non-pneumococcal and viral pneumonias are included in the group termed atypical pneumonias. They are caused by a wide range of bacteria and viruses; in most cases an aetiological diagnosis is not reached. Their clinical presentation is usually mild, although fatal cases have been described, principally in immunocompromised patients. Occasionally, extrapulmonary symptoms are associated, which makes diagnosis difficult. Microbiological tests are not indicated for diagnosis, except in the event of therapeutic failure or if the patient needs to be hospitalised. Early, empirical antibiotic treatment should be started as promptly as possible, since this has proven to reduce morbidity and mortality. Modifications to the treatment or associated viral treatment are only indicated according to the clinical progression or severity of the disease. Other treatments, such as corticotherapy, remain controversial.