CROUP in Children

Definition

Croup is a clinical syndrome, including a heterogeneous group diseases of larynx, infra/subglottis, trachea and bronchi, characterized by hoarseness, barking cough, stridor with or without inspiration of respiratory stress. often occurs in children.
 

Classification

 I. Croup generally classified into two groups, namely:

A. VIRAL CROUP (laringotracheobronhotis): Characterized by prodromal symptoms respiratory infections: Respiratory tract obstruction symptoms lasted 3-5 days. Age 6-6 years. Stridor (+), Cough (all of time), Fever (+) high, duration 2-7 days, Family history (+), Predisposition by asthma (-).

B. SPASMODIC CROUP : Spasmodic cough, there is atopic factor, without prodromal symptoms, child  can suddenly get respiratory tract obstruction, usually at night before take a bed, attacked for a while then return to normal.

II. Based on severity degrees, croup classified into 4 categories:

A. LIGHT: Marked by loud barking cough that sometimes arise,  Stridor which can't heard when the patient take a rest or no activities and light chest retraction.

B. MODERATE: Marked by  frequently barking cough, Stridor more can heard when patient less activities without respiratory distress.

C. SEVERE: Marked by frequently barking cough, Stridor inspiration more can heard when patient less activities or take a rest, and sometimes accompanied by expiratory stridor, chest wall retraction, also respiratory distress.

D. FAILED BREATH THREATENING: Cough sometimes isn't clear, stridor (+), impaired consciousness, and lethargy.

Etiology

Virus are common causes of Human Para-influenza Virus type 1 virus (HPIV-1) 60%, HPIV-2, 3 and 4, Influenza A and B viruses, Adenovirus, Respiratory Syncytial Virus (RSV) and Measles Virus.

Patophysiology
Virus transmission (mainly parainfluenza and RSV) can occur due to direct inoculation of secretion which carry the virus through the hands or by large inhalation particles entering through the eyes or nose. Virus infection in laryngotracheitis, laryngotracheobronchitis and laryngotracheobronchopneumonia usually starts from the nasopharynx or oropharynx which get down to the larynx and trachea after an incubation period of 2-8 days. Diffuse inflammation that causes erythema  and edema of the mucosa wall of the respiratory tract. Larynx is the narrowest part of upper respiratory tract, which makes it very suspectible to the occurrence of obstruction. The same mucosa edema in adults and children will lead to different refinement. Mucosa edema with 1 mm thickness will cause airway narrowing by 44% in children and 75% in infants.
Mucosa edema of glottis area will cause a disruption of vocal cord mobility. edema on subglottis area can also cause symptoms of shortness of breath. Airway narrowing due to inflammation causes air turbulence that causes stridor.
In Laryngotracheitis acute edematous area, there are histologically containing cellular infiltrates in the  lamina propria, submucosal and advensisia. These infiltrates contain histiocytes, lymphocytes, plasma cells, and neutrophils.

Clinical Manifestations

Clinical manifestations of Croup aren't preceded by such a high fever during  12-72 hours, runny nose, sore swallow, and mild cough. this condition will develop into a loud cough, the voice becomes hoarse and rough. Accompanying systemic symptoms such as fever and malaise. When severe conditions can occur shortness breath, severe stridor inspiratory, the child restless, and symptoms will worsen at night.

Treatment

1. The key management is treat of airway obstruction

2. Inhalation therapy using cold vapor to humidify respiratory tract, alleviate inflammation

3. Epinephrine Nebulation: Should be given to children with croup syndrome is accompanied by severe stridor at rest and require intubation, and children with retraction and stridor which failed by inhalation therapy

4. Corticosteroid: used to reduce edema in larynx by mucous anti inflammation mechanism. Dexamethasone given at a dose of 0,6 mg/kg/oral or IM, single dose, repeated within 6-24 hours. prednisone at a dose 1-2 mg/kg

Intubation endotracheal, conducted in patients with severe croup syndrome, which is not responsive to other therapies. The indications are hypercarbia and the threat of breath failure, there is an increasing stridor, increased frequency of breath, increased pulse rate, chest retraction, cyanosis, and impairment of consciousness.

References
1. http://www.mja.com.au/public/issues/179_07_061003/fit10207_fm.html
2. http://www.eguidelines.co.uk/user/login_newsys.php?
3. http://www.pedsradiology.com/Historyanswer.aspx?qid=303&fid=1
4. http://kidshealth.org/parent/infections/bacterial_viral/croup.html
5. http://www.nlm.nih.gov/medlineplus/ency/article/000959.htm
6. http://kamaroperasi.blogspot.com/2009/03/croup.html
7. http://pediatrics.about.com/cs/commoninfections/a/croup.htm
8. http://www.mayoclinic.com/health/croup/ds00312
9. http://www.virtualpediatrichospital.org/providers/ElectricAirway/Text/MICCroupSymptoms.shtml