What is chronic pneumonia?
By definition, chronic pneumonia is a lung infection that lasts at least 6 weeks [1].
Causes
Chronic pneumonia is usually caused by slowly growing microbes (Chart 1) [1,3,4]. Circumstances in which chronic pneumonia can develop:
- Acute pneumonia that does not respond well to treatment
- Untreated atypical pneumonia, for example Mycoplasma (walking) pneumonia
- Fungal pneumonia in individuals with poor immunity
Chronic pneumonia rarely occurs in otherwise healthy individuals.
Chart 1. Chronic Pneumonia Causes and Spread |
||
Cause |
Spread |
Disease |
| Bacteria | ||
| Actinomyces [6,13] | Aspiration of mouth bacteria | Thoracic actinomycosis |
| Mycobacterium tuberculosis [7] | Droplet, by coughing and sneezing | Pulmonary tuberculosis; cavities in lungs |
| Fungi | ||
| Aspergillus [10,15] | Inhalation from indoor or outdoor environment | Chronic necrotizing pulmonary aspergillosis |
| Blastomyces [3,8] | Inhalation from decaying vegetables and soil | Pulmonary blastomycosis; round lung mass, skin sores |
| Candida [4] | Aspiration of fungi that live in mouth or nose | Pulmonary candidiasis |
| Coccidioides [1,3,4] | Inhalation of microbes from soil during excavation work or travel | Pulmonary coccidiomycosis |
| Cryptococcus [9] | Inhalation of bird droppings from soil | Pulmonary cryptococcosis; associated with meningitis |
| Histoplasma [4,12] | Inhalation of bird and bat droppings (in barn cleaners, farmers, bridge painters) | Pulmonary histoplasmosis; lung cavities |
| Sporothrix [4] | Inhalation from decaying vegetables (in gardeners) | Pulmonary sporotrichosis; lung cavities |
| Parasites (one-cell) | ||
| Entamoeba [11,14] | Fecal-oral infection from water or food contaminated by human stool | Pulmonary amoebiasis; pleural effusion, liver abscess |
| Parasites (worms) | ||
| Ancylostoma [11] | Fecal-oral infection by food contaminated by human stool; or through skin cuts | Pulmonary ancylostomiasis; bronchopneumonia |
| Ascaris [11] | Fecal-oral infection by food contaminated by human stool | Pulmonary ascariasis; lung granulomas |
| Schistosoma [11] | Ingestion of parasites during swimming in water contaminated by human stool | Pulmonary schistosomiasis; lung nodules, enlarged liver |
| Strongyloides [11] | Autoinfection from the stool in the intestine; in HIV/AIDS; in South Asia | Pulmonary strongyloidiasis; bronchopneumonia |
What is recurrent pneumonia?
Recurrent pneumonia is defined as two or more episodes of lower respiratory tract infection separated by at least a month [1]. Common causing microbes are Streptococcus pneumoniae and Haemophilus influenzae [17].
Risk Factors
Risk factors for chronic and recurrent pneumonia [1,3,4,17]:
- Impaired immunity, for example, in HIV/AIDS, chemotherapy, corticosteroid or immunosuppressant therapy, removed spleen (asplenia), low blood leukocytes (neutropenia)
- Underlying chronic diseases: chronic obstructive pulmonary disease (COPD), bronchiectasis, alcoholism, diabetes mellitus, cancer, leukemia, cystic fibrosis [16]
- Chronic conditions that allow frequent aspiration: difficulty swallowing, neurological conditions (dementia, Parkinson’s disease), alcoholism, seizures, gastroesophageal reflux disease (GERD) [18]
Symptoms
Symptoms of chronic pneumonia usually develop slowly, can be mild or severe and can include [2,3]:
- Persistent dry cough or, rarely, coughing up yellow or green mucus or blood, chest pain during coughing
- Shortness of breath during exercise
- Low-grade fever, night sweets
- Anorexia, weight loss
- Fatigue
- Swollen lymph nodes in the chest, neck and armpits
- Skin rash
Diagnosis
Tests to identify microbes [11]:
- Culture from blood, sputum and bronchial secretions
- Antibodies against microbes (IgE antibodies in parasites)
- Blood cells: eosinophils in parasitic pneumonia
X-ray can show patchy lung infiltrates (bronchopneumonia), lung cavities, abscesses or enlarged chest lymph nodes [11].
Differential Diagnosis
Health conditions that can mimic chronic or recurrent pneumonia [4]:
- Chronic eosinophilic pneumonia
- Pneumonitis
- Coal worker’s pneumoconiosis
- Interstitial pulmonary fibrosis
- Chronic bronchitis
Treatment
Treatment includes management of the underlying diseases, antibiotics for bacterial pneumonia, antifungals for fungal and metronidazole and other antiparasitic drugs for parasitic pneumonia.
- References
- Gepper EF, 1992, Chronic and recurrent pneumonia PubMed
- Zuger A, 2001, How Long Does Pneumonia Take to Go Away? NEJM Journal Watch
- Chronic Pulmonary Infections The Ohio State University
- Mandanas RA, Fungal pneumonia Emedicine
- Kurdgelashvili G, Nocardiosis Emedicine
- Mabeza GF et al, 2003, Pulmonary actinomycosis European Respiratory Journal
- Pinto LM et al, 2010, Pulmonary tuberculosis masquerading as community acquired pneumonia ScienceDirect
- Okereke CC, Blastomycosis Emedicine
- King JW, Cryptococcosis Emedicine
- Harman EM, Aspergillosis Emedicine
- Cheepsattayakorn A et al, 2014, Parasitic Pneumonia and Lung Involvement Hindawi
- Fayyaz Y, Histoplasmosis Emedicine
- Okulicz JF, Actinomycosis Emedicine
- Entamoeba histolytica – Pathogen Safety Data Sheet Public Health Agency of Canada
- Argento A, 2013, Master Differential Diagnosis: Internal Medicine, p. 388
- Cystic fibrosis MedlinePlus
- Garcia-Vidal C et al, 2009, Aetiology of, and risk factors for, recurrent community-acquired pneumonia
PubMed - Mikita CP, Aspiration syndromes, clinical presentation Emedicine