Items tagged “infectious disease”

Achalasia (primary achalasia) is a failure of organized esophageal peristalsis causing impaired relaxation of the lower esophageal sphincter, and resulting in food stasis and often marked dilatation of the esophagus.  Obstruction of the distal esophagus from other non-functional etiologies, not...

Acute unilateral airspace opacification is a subset of the differential diagnosis for airspace opacification.   Differential diagnosis The exhaustive list of all possible causes would be huge, but a useful framework includes: pus, i.e. pulmonary infection bacterial pneumonia fungal pneumoni...

Bell palsy, also known as idiopathic peripheral facial paralysis, is characterized by rapid onset facial nerve paralysis, often with resolution in 6-8 weeks, without an identifiable etiology. As there are numerous causes of facial nerve palsy, many acute in onset, it is currently a diagnosis of ...

Chronic bilateral airspace opacification is a subset of the differential diagnosis for airspace opacification. An exhaustive list of all possible causes of chronic bilateral airspace opacities is long, but a useful framework is as follows: inflammatory sarcoidosis granulomatosis with polyangi...

Fournier gangrene is necrotizing fasciitis of the perineum. It is a true urological emergency due to the high mortality rate but fortunately, the condition is rare. It is primarily a clinical diagnosis and definitive treatment, typically consisting of surgical debridement and antibiotics. Imagin...

Herpes simplex (HSV) encephalitis is the most common cause of fatal sporadic fulminant necrotizing viral encephalitis and has characteristic imaging findings.  Two subtypes are recognized which differ in demographics, virus, and pattern of involvement. They are 1: neonatal herpes encephalit...

Pulmonary Pneumocystis jiroveci infection, also known as Pneumocystis jiroveci pneumonia (PJP) or Pneumocystis pneumonia (PCP), is an atypical pulmonary infection and the most common opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). Terminology Classically, "P...

Leptomeningitis, which is more commonly referred to as meningitis, represents inflammation of the subarachnoid space (i.e. arachnoid mater and pia mater) caused by an infectious or noninfectious process. Pathology Etiology Infective pyogenic meningitis elderly Streptococcus pneumoniae Lis...

Mnemonics for peripheral lung opacities seen on chest x-ray or CT are useful to remember differentials. Examples include: AEIOU SIC CUE Mnemonics AEIOU A: alveolar sarcoidosis E: eosinophilic pneumonia I: infarction O: organizing pneumonia (including COP) U: usual interstitial pneumonit...

Tree-in-bud sign or pattern describes the CT appearance of multiple areas of centrilobular nodules with a linear branching pattern. Although initially described in patients with endobronchial tuberculosis, it is now recognized in a large number of conditions. Pathology Pathogenesis Simply put...

Causes of neonatal distress can be broadly split into intrathoracic, extrathoracic and systemic: Intrathoracic Medical respiratory distress syndrome (RDS) transient tachypnea of the newborn (TTN) meconium aspiration syndrome bronchopulmonary dysplasia (BPD) patent ductus arteriosus (PDA) ...

Pulmonary manifestations of tuberculosis are varied and depend in part whether the infection is primary or post-primary. The lungs are the most common site of primary infection by tuberculosis and are a major source of spread of the disease and of individual morbidity and mortality. A general d...

Tuberculous meningitis is the most common presentation of intracranial tuberculosis, and usually refers to infection of the leptomeninges. Uncommonly tuberculosis can be limited to the pachymeninges (dura mater), it is called tuberculous pachymeningitis and is discussed separately.  The remaind...

The bulging fissure sign refers to lobar consolidation where the affected portion of the lung is expanded, causing displacement of the adjacent fissure. Any type of pneumonia or space-occupying process can lead to bulging (sagging) fissure sign. Classically, it has been described in right upper ...

There are several causes leading to a perfusion defect on a VQ scan with an acute pulmonary embolus being only one of them: Vascular causes acute pulmonary embolus previous pulmonary embolus (including fat embolism, thromboembolism, air embolism, tumor) vasculitides affecting the pulmonary v...

Pulmonary Mycobacterium avium complex (MAC) infection is a type of non-tuberculous mycobacterial (NTM) infection. It is relatively common and continues to pose significant therapeutic challenges. In addition, the role of MAC in pulmonary pathology remains controversial in many instances.  Epide...

Acute pyelonephritis (plural: acute pyelonephritides) is a bacterial infection of the renal pelvis and parenchyma most commonly seen in young women. It remains common and continues to have significant morbidity in certain groups of patients. Epidemiology The incidence of acute pyelonephritis p...

Whipple disease is a rare infectious multisystem disorder caused by the actinobacteria Tropheryma whipplei. Epidemiology The incidence of Whipple disease is not truly known, one Swiss study estimated it at approximately 1 per 1.5 million per year 7. The peak age for presentation is in the fif...