3 | DISCUSSION
In this article, we describe an interesting case of pulmonary
actinomycosis in a patient with a background of COPD, heavy smoking, and
poor dental hygiene. The patient’s initial presentation with pleuritic
chest pain, fever, productive cough, and dyspnea may give the impression
of a clinical diagnosis of pneumonia. This makes pulmonary actinomycosis
a very challenging condition to diagnose, and physicians need to
maintain a high index of suspicion.
Actinomyces is a common commensal that forms part of the normal flora of
the oral cavity. Pulmonary actinomycosis is caused by aspiration of the
oropharyngeal secretions; this results in a direct invasion of the
bronchopulmonary tree, putting the lower segments of the right lung at a
higher risk [4]. Moreover, individuals with poor dental hygiene and
alcoholism are more susceptible to develop pulmonary actinomycosis,
which was the case in our patient. Other predisposing factors for
pulmonary actinomycosis infection include underlying lung disorders such
as chronic bronchitis, emphysema, and bronchiectasis [5], which was
also noted in our case.
The radiological features of pulmonary actinomycosis aren’t specific;
they may include consolidation, cavitation, abscess formation, draining
sinuses, mass, and hilar or mediastinal lymph node enlargement. Pleural
involvement may also result in pleural effusion, thickening, or empyema
in about 15%–50% of cases [6]. These different findings make
pulmonary actinomycosis difficult to spot early, leading to it being
misdiagnosed as lung malignancy or pulmonary tuberculosis.
The diagnosis of pulmonary actinomycosis is challenging due to the
difficulty of isolating the organism. Simple culture using a sputum
sample, either expectorated or extracted using bronchoalveolar lavage
(BAL), is inadequate for the diagnosis of pulmonary actinomycosis unless
the patient presents with lung cavitation [2, 7]. The gold standard
for diagnosis is the histopathological examination and bacterial culture
in anaerobic conditions from a pleural biopsy sample, looking for
gram-positive branching filamentous rods with yellow sulfur granules
[1–3]. Although sulfur granules are considered to be a
pathognomonic histological feature and quite suggestive of actinomyces,
it is important to know that sulfur granules can also be found in
nocardiosis, coccidioidomycosis, and aspergillosis [8]. Moreover, it
is quite helpful to realize that a sample taken from the pleural
effusion in patients with pulmonary actinomycosis is unlikely to grow or
yield any bacterial growth [2].
The treatment regimen for pulmonary actinomycosis requires a prolonged
course of high doses of beta-lactam antibiotics such as penicillin G,
amoxicillin, or cephalosporin. The recommended treatment duration is
6–12 months with the administration of antibiotics intravenously over
2–6 weeks, followed by oral medications [3, 5]. In patients with
penicillin allergies, the recommended options include clindamycin,
doxycycline, and erythromycin, with the latter being a safe option for
pregnant women [1–3]. Antibiotics are the cornerstone of
actinomycosis treatment, and a good response is usually observed, as
seen in our patient. Nevertheless, surgical management is indicated in
patients who develop massive hemoptysis or a localized lung infection
such as (empyema, or abscess), also in cases of sinus tracts or
fistulas, and finally in those who don’t respond to medical treatment
[9].
ACKNOWLEDGEMENT
Not applicable.
CONFLICTS OF INTEREST
All authors declare that there are no conflicts of interest.
CONSENT
Written consent for publication has been obtained from the patient and
the authors.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the
corresponding author upon reasonable request.