Items tagged “infectiousdisease”

127 results found

Acute mastoiditis

Acute mastoiditis is largely a disease of childhood and occurs when acute otitis media extends into the mastoid air cells.  Terminology When mastoiditis and acute otitis media occur concurrently, sometimes the term acute otomastoiditis is used.  When mucoperiosteal involvement evolves into bo...

Air crescent sign (lung)

An air crescent sign describes the crescent of air that can be seen in invasive aspergillosis, semi-invasive aspergillosis or other processes that cause pulmonary necrosis. It usually heralds recovery and is the result of increased granulocyte activity. In angioinvasive fungal infection, the no...

Idiopathic interstitial pneumonia (mnemonic)

Idiopathic interstitial pneumonias (IIPs) are diffuse interstitial lung diseases of unknown cause. A useful mnemonic for the American Thoracic Society-European Respiratory Society (ATS-ERS) classification of IIPs is: All Idiopathic Chronic Lung Disease aRe Nonspecifically Patterned The mnemoni...

Bat wing opacities (lungs)

Bat's wing or butterfly pulmonary opacities refer to a pattern of bilateral perihilar shadowing. It is classically described on a frontal chest radiograph but can also refer to appearances on chest CT 3-4. Differential diagnosis Bat's wing pulmonary opacities can be caused by: pulmonary oedem...

Chronic unilateral airspace opacification (differential)

Chronic unilateral airspace opacification is a subset of the differential diagnoses for airspace opacification. An exhaustive list of all possible causes of chronic unilateral airspace opacities is long, but a useful framework is as follows: neoplastic post obstructive lymphoma lymphocytic ...

Eosinophilic lung disease

Eosinophilic lung diseases are a heterogenous group of disorders that are characterised by excess infiltration of eosinophils within the lung interstitium and alveoli and are broadly divided into three main groups 1: idiopathic: unknown causes secondary: known causes eosinophilic vasculitis: ...

Ground-glass opacification

Ground-glass opacification/opacity (GGO) is a descriptive term referring to an area of increased attenuation in the lung on computed tomography (CT) with preserved bronchial and vascular markings. It is a non-specific sign with a wide aetiology including infection, chronic interstitial disease a...

Varicella pneumonia

Varicella pneumonia is a type of viral pneumonia. It is a common cause of multiple small round calcific lung lesions. Varicella-zoster virus most commonly causes self-limited benign disease (chickenpox) in children. However, in adults it tends to cause significant complications including varicel...

Respiratory distress syndrome

Respiratory distress syndrome (RDS) is a relatively common condition resulting from insufficient production of surfactant that occurs in preterm neonates.  On imaging, the condition generally presents as bilateral and relatively symmetric diffuse ground glass lungs with low volumes and a bell-s...

Idiopathic interstitial pneumonias

Idiopathic interstitial pneumonias (IIPs) are diffuse interstitial lung diseases of unknown cause. They are characterized by cellular infiltration of the interstitial compartment of the lung with varying degrees of inflammation and fibrosis. Classification For many years many attempts have bee...

Septal lines in lung

Septal lines, also known as Kerley lines, are seen when the interlobular septa in the pulmonary interstitium become prominent. This may be because of lymphatic engorgement or oedema of the connective tissues of the interlobular septa. They usually occur when pulmonary capillary wedge pressure re...

Miliary opacities (lungs)

The term miliary opacities refers to innumerable, small 1-4 mm pulmonary nodules scattered throughout the lungs. It is useful to divide these patients into those who are febrile and those who are not. Additionally, some miliary opacities are very dense, narrowing the differential - see multiple...


Neuroblastomas are tumours of neuroblastic origin. Although they may occur anywhere along the sympathetic chain, the vast majority arise from the adrenal gland. They represent the most common extracranial solid childhood malignancy and are the third commonest childhood tumour after leukaemia an...


Otomastoiditis, or more simply inflammation of the mastoid air cells, can be divided into two distinct entities: acute otomastoiditis: usually due to bacterial infection chronic otomastoiditis: usually due to Eustachian tube dysfunction

Pulmonary sequestration

Pulmonary sequestration, also called accessory lung, refers to the aberrant formation of segmental lung tissue that has no connection with the bronchial tree or pulmonary arteries. It is a bronchopulmonary foregut malformation (BPFM). There are two types: intralobar sequestration (ILS) extral...

Hepatic abscess

Hepatic abscesses, like abscesses elsewhere, are localised collections of necrotic inflammatory tissue caused by bacterial, parasitic or fungal agents.  Epidemiology The frequency of individual infective agents as causes of liver abscesses are intimately linked to the demographics of the affec...

Reverse bat wing pulmonary opacities

Reverse bat wing pulmonary opacities refer to peripheral opacities of the lungs, sparing the perihilar region. It is a relatively unusual appearance with a relatively narrow differential: chronic eosinophilic pneumonia organising pneumonia (formerly bronchiolitis obliterans with organising pne...


Pneumothorax refers to the presence of gas (air) in the pleural space. When this collection of gas is constantly enlarging with resulting compression of mediastinal structures, it can be life-threatening and is known as a tension pneumothorax. For those pneumothoraces occurring in neonates see t...


Spondylodiscitis is characterised by infection involving the intervertebral disc and adjacent vertebrae. Epidemiology Spondylodiscitis has a bimodal age distribution, which many authors consider essentially as separate entities: paediatric older population ~50 years Clinical presentation T...

Pulmonary Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) can be seen as part of widespread involvement in patients with disseminated LCH or more frequently as a distinct entity in young adult smokers. This article focuses on the latter.  Epidemiology PLCH is usually identified in young adults (20-40 yea...

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