Broadening of the soft tissues (non-edematous swelling of soft tissues) of the digital tips in all dimensions associated with an increased longitudinal and lateral curvature of the nails.

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event.

A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation.

Difficult or labored breathing. Dyspnea is a subjective feeling only the patient can rate, e.g., on a Borg scale.

Replacement of normal lung tissues by fibroblasts and collagen.

Perceived difficulty to breathe that occurs with exercise or exertion and improves with rest.

Very rapid breathing.

Interstitial lung disease (ILD), or pneumonitis, is a heterogeneous group of disorders characterized pathologically by expansion of the interstitial compartment of the lung by inflammatory cells. Fibrosis occurs in many cases (Visscher and Myers, 2006). See also interstitial lung disease-1 (ILD1; 619611). Desquamative interstitial pneumonitis (DIP) was originally described as a pathologic entity by Liebow et al. (1965). Lung biopsy shows diffuse and uniform filling of alveoli by clusters of cells which Liebow et al. (1965) speculated to be 'desquamated pneumocytes.' Since then, these cells have been shown primarily to be pigmented alveolar macrophages. Other features include thickened alveolar septa with an infiltrate of inflammatory cells and plump, cuboidal type II pneumocytes. Mild collagen deposition without architectural distortion or honeycombing may be present. Different forms of ILD represent pathologic classifications based on histologic patterns rather than clinical diagnoses and may occur in a variety of clinical contexts (Visscher and Myers, 2006). Although DIP occurs most often as a sporadic disorder in adults during the third to fifth decade of life and is highly associated with smoking (Carrington et al., 1978), reports of a familial form with onset in infancy and early death suggest a genetic basis (Sharief et al., 1994). Cases of DIP reported in infants are often more severe and refractory to treatment than those reported in adults (Nogee et al., 2001).

Honeycombing represents destroyed and fibrotic lung tissue containing numerous cystic airspaces with thick fibrous walls, representing the late stage of various lung diseases, with complete loss of acinar architecture. The cysts range in size from a few millimeters to several centimeters in diameter, have variable wall thickness, and are lined by metaplastic bronchiolar epithelium. On chest radiographs, honeycombing appears as closely approximated ring shadows, typically 3-10 mm in diameter with walls 1-3 mm in thickness, that resemble a honeycomb; the finding implies end-stage lung disease. On CT scans, the appearance is of clustered cystic air spaces, typically of comparable diameters on the order of 3-10 mm but occasionally as large as 2.5 cm. Honeycombing is usually subpleural and is characterized by well-defined walls. It is a CT feature of established pulmonary fibrosis. Because honeycombing is often considered specific for pulmonary fibrosis and is an important criterion in the diagnosis of usual interstitial pneumonia, the term should be used with care, as it may directly impact patient care.

Paraseptal emphysema is characterized by predominant involvement of the distal alveoli and their ducts and sacs. It is characteristically bounded by any pleural surface and the interlobular septa. This emphysema is characterized by subpleural and peribronchovascular regions of low attenuation separated by intact interlobular septa, sometimes associated with bullae.

Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea.

An abnormally low level of blood oxygen.

A severe form of respiratory insufficiency characterized by inadequate gas exchange such that the levels of oxygen or carbon dioxide cannot be maintained within normal limits.

Temporally uniform (all lesions are in the same stage of evolution) pattern of diffuse inflammatory interstitial process, mostly symmetric over the entire lung, involving mainly the alveolar septa.

Radiological appearance of increased density around the walls of a bronchus or large bronchiole. This feature is thought to be related to edema involving the bronchial wall as well as the peribronchial interstitial space. If the cross section of a bronchus is captured in a radiograph or computed tomography image, it is said to have the appearance of a donut because of the central lucency representing the airway of the bronchus surrounded by a circular region of increased density.

Respiratory difficulty as newborn.

On pulmonary high-resolution computed tomography, reticular pattern is characterized by innumerable interlacing shadows suggesting a mesh.

The so-called crazy paving pattern appears as thickened interlobular septa and intralobular lines superimposed on a background of ground-glass opacity, resembling irregularly shaped paving stones. The crazy-paving pattern is often sharply demarcated from more normal lung and may have a geographic outline. It was originally reported in patients with alveolar proteinosis and is also encountered in other diffuse lung diseases that affect both the interstitial and airspace compartments, such as lipoid pneumonia.

A nodular pattern is characterized on pulmonary high-resolution computed tomography by the presence of numerous rounded opacities that range from 2 mm to 1 cm in diameter, with micronodules defined as smaller than 3 mm in diameter.

On pulmonary high-resolution computed tomography, the cystic pattern is composed by well-defined, round and circumscribed air-containing parenchymal spaces with a well-defined wall and interface with normal lung. The wall of the cysts may be uniform or varied in thickness, but usually is thin (less than 2 mm) and occurs without associated emphysema.

Temporal and spatial heterogeneity in lungs based on presence of fibrosis and honeycombing.

Significantly decreased level or failed detection of surfactant protein C in broncho-alveolar lavage fluid. Comment

Accumulation of amorphous PAS-positive material in the space between alveolar macrophages, sometimes as condensed form (oval bodies) are typically found in alveolar proteinosis.

On chest radiographs, ground-glass opacity appears as an area of hazy increased lung opacity, usually extensive, within which margins of pulmonary vessels may be indistinct. On CT scans, it appears as hazy increased opacity of lung, with preservation of bronchial and vascular margins. It is caused by partial filling of airspaces, interstitial thickening (due to fluid, cells, and/or fibrosis), partial collapse of alveoli, increased capillary blood volume, or a combination of these, the common factor being the partial displacement of air. Ground-glass opacity is less opaque than consolidation, in which bronchovascular margins are obscured.

Bluish discoloration of the skin and mucosa due to poor circulation or inadequate oxygenation of arterial or capillary blood.