A truck driver presented with history of fever since four weeks, and dry cough. He also gives a history of weight loss of about 10 kg. X-ray shows bilateral reticulonodular infiltrates. The most likely diagnosis is:
Answer is B (Pneumocystis carinii Pneumonia): Presence of prolonged fever, weight loss and bilateral reticulonodular infiltrates in a person at increased risk of HIV (Long distance Truck drivers in India) suggests a diagnosis of Atypical pneumonia due to Pneumocystis carinii infection. Note Pneumocystic Pneumonia in Adults In adults the disease appears to be predominantly alveolar Air spaces (alveoli) are filled with a foamy, eosinophilic exudate and appear honey coombed The intra-alveolar exudate consists of organisms, surface glycoprotein exudate and debri of macrophages and inflammatory cells. Pneumocystis Pneumonia in molnourished infants In infants the disease has a predominant interstitial component The interstitium is filled with fluid plasma cells and lymphocytes. These formed elements seem to overflow into air spaces which are filled with a frothy eosinophilic exudates. Pneumocystic pneumonia is one of the most common AIDS - defining oppounistic infections and should be considered in any patient presenting with atypical pneumonia who is at increased risk of acquiring HIV (eg Professional sex workers, Homosexuals men, Intravenous drug users and Long distance Truck drivers in India) Presentation of patient is consistant with diagnosis of Pneumocystic Pneumonia Pneumocystis carinii is an impoant cause of Atypical Pneumonia in immunocompromised states especially AIDS Pneumocystic Pneumonia is recognized as one of the most common AIDS defining oppostunistic infections. `A diagnosis of Pneumocystic pneumonia should be considered in any patient presenting with sings / symptoms of Atypical Pneumonia in a patient who is at increased risk of acquiring HIV infection' Long Distance Truck Drivers in India are considered a high risk population for contracting the HIV virus (Nag, 1996) Charachteristic clinical manifestations include significant weight loss, fever, non productive cough and dysponea Clinical Manifestations (Textbook of Pulmonary Medicine' by Behera 2"d/413) Profound weight loss 100%) Fever 97%) Dyspnea ( 63%) Non Productive cough 75%) The most charachteristic finding an chest X-Ray is bilateral diffuse infiltrates beginning in the perihilar region although various atypical manifestations including nodular lesions, cavitatory lesions etc have also been repoed The classic finding on chest radiography consists of bilateral diffuse infiltrates beginning in the perihilar region However no radiographic pattern is pathognomic for pneumocystic pneumonia. Tuberculosis is unlikely as it usually present with productive cough and the patient in question has a non productive dry cough. Also, bilateral diffuse reticulonodular infiltrates are not charachteristic of Tuberculosis. Interstitial Luna Diseases is unlikely as these disorders usually do not present with fever and weight loss, although bilateral reticulonodular infiltrates may be seen on chest x-Ray. 'With most interstitial lung diseases, constitutional symptoms like fevers, chills and weight loss are absent'- Fishman's Pulmonary Diseases Note: Patients with Acute Interstitial Pneumonias (Type of ILD) may present with the a similar clinical and radiological picture, but these disorders constitute only a small fraction of Interstitial Lung Diseases (< 1%). Pneumonia is unlikely as it presents with typical features of pneumonia including productive cough and consolidation on chest x-rays. The patient in question has a form of atypical pneumonia. AIR Space Penumonia (Typical Pneumonia) Interstitial Pneumonia (Atypical Pneumonia) Exudate in alveoli i.e. consolidation No exudate, alveoli are air tilled i.e. no consolidation (infiltrate in interstitium) Infiltrate is primarily of neutrophills (PMN) Infiltrate is primarily lymphatic Agents responsible are extracellular Agents responsible are intracellular Cough is productive of purulent sputum Cough is dry Chest X-ray shows alveolar pattern Chest X-ray shows interstitial pattern
Tuberculosis
Pneumocystis carinii Pneumonia
Pneumococcal pneumonia
Interstitial Lung Disease